NCHurricane2009's Blog

2016 Atlantic Hurricane Season Birdseye Discussion #180

By: NCHurricane2009, 6:01 AM GMT on November 27, 2016

***To track what is left of former Atlantic Tropical Storm Otto which recently crossed over into the eastern Pacific...an eastern pacific view has been added in the atmospheric and thermodynamic charts below***

...SUNDAY NOVEMBER 27 2016 1:00 AM EDT...
The following statement concerns area of interest #1 marked over the eastern Pacific in the atmospheric features chart below. Under unfavorable easterly vertical shear induced by the south side of an upper ridge over southern Mexico...Tropical Storm Otto has degenerated into a remnant surface trough. In addition there is plenty of dry air in Otto's environment that may have contributed to the dissipation of the tropical storm. The dry air may have been produced by upper-level convergence and resulting sinking air due to upper-level southeasterlies induced by the southwest side of Caribbean upper ridging clashing with upper-level northeastleries induced by the southeast side of the southern Mexico upper ridge. This is my final statement on this system on this blog...and with no other areas of interest this will be my final blog update until the threat of tropical activity returns to the Atlantic basin.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1928Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #179

By: NCHurricane2009, 10:12 PM GMT on November 25, 2016

**An earlier lack of upper-level wind data for the atmospheric features chart due to data outage...then thanksgiving holiday activities...have prevented me from getting this blog update out by this morning as promised in special update #178A. Apologies for the belated blog post***

...FRIDAY NOVEMBER 25 2016 5:30 PM EDT...
Otto moves into the eastern Pacific Ocean from Costa Rica and Nicaragua while weakening to a tropical storm...but will continue to issue special feature sections with forecasts on Otto on this blog. See the special feature section below for additional details on Otto. Visit www.nhc.noaa.gov for up to the minute latest information on Otto.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1200Z and 1328Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

...SPECIAL FEATURE...TROPICAL STORM OTTO...
Current Prognosis...Since speical update #178A...Otto weakend to a tropical storm while moving across Nicaragua and Costa Rica...and remains a tropical storm while moving into the eastern Pacific Ocean. Otto is situated south of a southern Mexico upper ridge axis where upper easterlies are shearing thunderstorms slightly to the west of the surface spin. Based on the latest satellite animation...Otto should be approaching 9.5N-90W by 0000Z tonight.

Atmospheric Outlook for the Forecast Period...Otto continues westward while steered by surface ridging across North America. By 72 to 96 hours...a large surface frontal system supported by an upper trough moving into western North America will create a gap between the North America surface ridge and central Pacific surface ridge that will likely cause Otto to slow down and bend northward in track...and its possible that by the end of the 120 hour forecast period Otto turns more westward while reaching the southeastern periphery of the central Pacific surface ridge. Upper-level winds could become more favorable for Otto as the southern Mexico upper ridge mentioned in the above current prognosis section gets pushed southward directly over Otto by the upper trough moving into western North America...in which case the upper ridge will stop shearing and start ventilating Otto. This may allow Otto to re-strenghen late in the forecast period.

Thermodynamic Outlook for the Forecast Period...Otto will be passing over favorable 29 to 30 deg C waters over the eastern Pacific during the forecast period.


My (red) track and intensity forecast points in the above graphic:

24 Hr Forecast (0000Z Nov 27)...50 mph maximum sustained wind tropical centered over the eastern Pacific at 9.5N-95W

48 Hr Forecast (0000Z Nov 28)...50 mph maximum sustained wind tropical storm centered over the eastern Pacific at 9.8N-100W

72 Hr Forecast (0000Z Nov 29)...70 mph maximum sustained wind tropical storm centered over the eastern Pacific at 10.5N-102.5W

96 Hr Forecast (0000Z Nov 30)...80 mph maximum sustained wind hurricane centered over the eastern Pacific at 11.5N-105W

120 Hr Forecast (0000Z Dec 1)...100 mph maximum sustained wind hurricane centered over the eastern Pacific at 12N-108W

Track Forecast...Otto by 0000Z (6 PM CST) tonight will be arriving to a position that is slightly southwest of my previous forecast track and so I have adjusted my forecast slightly southwest accordingly. Forecast track shows a slow down with a bend to the north at 72 to 96 hours...followed by a turn towards the west at 120 hours...per the steering influences mentioned in the above atmospheric outlook section.

Intensity Forecast...Under easterly vertical shear Otto appears to be on track to weaken further to 50 mph maximum sustained winds in the short term. Then as upper-level winds become more favorable in the 72 to 120 hour forecast timeframe...I show re-strengthening of Otto into a hurricane (see above atmospheric outlook seciton for how upper-level winds are expected to become more favorable). My current intensity forecast is unchanged from my previous one and thus is a continuation of my previous one.

Impact Forecast...The impact swath in the above forecast graphic is an extrapolation of the 3 PM CST NHC tropical storm wind field along my forecast track...with the swath grown in size later in the forecast to reflect the potential for re-strengthening.

2016 Atlantic Hurricane Season Birdseye Discussion #178A (Special Update)

By: NCHurricane2009, 6:43 PM GMT on November 24, 2016

...THURSDAY NOVEMBER 24 2016 1:45 PM EDT...
Hurricane Otto makes history by rapidly strengthening into a maximum category 2 with 110 mph maximum sustained winds...and making landfall in Nicaragua just norht of the Costa Rica/Nicaragua border...an area that does not commonly see hurricanes of this intensity. Flash flooding is expected over parts of Nicaragua and Costa Rica...and significant wind damage is expected near the center at the landfall location and part of the way inland. As a result of its current intensity and current forward pace...Otto is expected to survive its passage across Central America and move into the eastern Pacific. In such a scenario the National Hurricane Center would retain the name Otto and I would continue to issue special feature sections with forecasts on Otto.

I will be issuing my next full blog update on Otto and the rest of the Atlantic tropics either late tonight or early tomorrow morning. Visit www.nhc.noaa.gov for up to the minute latest information on Otto...including watches and/or warnings that are currently in effect.

2016 Atlantic Hurricane Season Birdseye Discussion #178

By: NCHurricane2009, 10:28 AM GMT on November 24, 2016

...THURSDAY NOVEMBER 24 2016 5:30 AM EDT...
Hurricane Otto approaching landfall in Nicaragua and Costa Rica...preparations in warned areas should have been completed by now. See the special feature section below for additional details on Otto. Visit www.nhc.noaa.gov for up to the minute latest information on Otto...including watches and/or warnings that are currently in effect.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1946Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

...SPECIAL FEATURE...HURRICANE OTTO...
Current Prognosis...Since the previous blog update...Otto briefly weakened to a tropical storm while ingesting some cool dry air delivered far south by the 1002 mb frontal cyclone in the western Atlantic. However as the frontal cyclone continues moving eastward and away...Otto has re-developed a large comma shaped thunderstorm field and is back at hurricane strength...even stronger than ever at 85 mph maximum sustained winds while approaching Nicaragua and Costa Rica. As of 0000Z earlier in the night the center of Otto passed over 11.2N-81.5W...and as of 0600Z this morning the center passed over 11.2N-82.2W which provides a current motion of about 0.7W longitude per 6 hours (or 2.8W longitude per 24 hours).

Atmospheric Outlook for the Forecast Period...Otto continues to move westward while steered by surface ridging across North America...but the ridge currently has a weakness generated by a 1012 mb frontal cyclone moving into the eastern US such that Otto is only slow moving to the west at the present time. After 24 hours as the aformentioned frontal cyclone leaves North America...the steering ridge will re-build and accelerate Otto across Central America and into the eastern Pacific. By the end of the 120-hour forecast period...a large surface frontal system supported by an upper trough moving into western North America will create a gap between the North America surface ridge and central Pacific surface ridge that will likely cause Otto to slow down again. As Otto moves into the eastern Pacific...it will likely encounter unfavorable easterly vertical shear on the south side of an upper ridge over southern Mexico...but by the end of the 120-hour forecast period this upper ridge will shift southward and possibly ventilate and re-stregnthen Otto while becoming pushed by the aformentioned upper trough moving into western North America.

Thermodynamic Outlook for the Forecast Period...Otto will be over favorable 29 deg C waters in the southern Caribbean...and then by the end of the 120-hour forecast period reach warmer 29 to 30 deg C waters in the eastern Pacific.


My (red) track and intensity forecast points in the above graphic:

24 Hr Forecast (0000Z Nov 25)...70 mph maximum sustained wind tropical storm centered inland over the Nicaragua/Costa Rica border at 11N-84.3W

48 Hr Forecast (0000Z Nov 26)...50 mph maximum sustained tropical storm centered over the eastern Pacific at 11N-89.3W

72 Hr Forecast (0000Z Nov 27)...50 mph maximum sustained wind tropical centered over the eastern Pacific at 11N-94.3W

96 Hr Forecast (0000Z Nov 28)...50 mph maximum sustained wind tropical storm centered over the eastern Pacific at 11N-99.3W

120 Hr Forecast (0000Z Nov 29)...70 mph maximum sustained wind tropical storm centered over the eastern Pacific at 11N-102.5W

Track Forecast...The initial first 24 hours of my updated forecast track is based on the current 2.8W longitude rate of progression noted in the above current prognosis section. I then accelerate the westward track after 24 hours as the surface ridge over North America re-builds per the above atmospheric outlook section...now catching up to the latest model guidance which has been going with a faster westward track than my previous forecasts showed. By 120 hours I slow the westward pace of Otto again as Otto gets caught in a gap between the North America surface ridge and central Pacific surface ridge per the above atmospheric outlook section.

Intensity Forecast...Otto is likely to strengthen beyond its current 85 mph maximmum sustained wind intensity before landfall in Nicaragua and Costa Rica...but I have lowered the intensity forecast for the timeframe that is 24 hours away as the updated faster forecast track moves Otto into land sooner and in fact by later today. However I have set the 24-hour forecast point at maximal tropical storm strength (70 mph) to account for the fact Otto will have just made landfall as a strong hurricane not long before the 24-hour forecast point. The updated faster forecast track makes it likely that Otto will survive its passage across Central America into the eastern Pacific. If so...the National Hurricane Center would retain the name Otto and I would continue to issue special feature sections with forecasts on Otto. Over the eastern Pacific...I initially show additional weakening to 50 mph maximum sustained winds due to expected easterly vertical shear mentioned in the above atmospheric outlook section. I then maintain a 50 mph intensity in the forecast through 96 hours as upper wind forecasts suggest the shearing upper-level easterlies will become divergent in nature...which would help ventilate Otto in the shear regime. By the end of the 120 hour forecast period...upper-level winds could become more favorable for Otto per the above atmospheric outlook section...and thus I show re-strengthening by that time.

Impact Forecast...The impact swath in the above forecast graphic is an extrapolation of the 4 AM EDT NHC tropical storm wind field along my forecast track...with the swath initially shrunken to reflect forecast weakening...and then re-expanded at the end of the forecast period to reflect forecast re-strengthening.

2016 Atlantic Hurricane Season Birdseye Discussion #177

By: NCHurricane2009, 4:41 AM GMT on November 23, 2016

...TUESDAY NOVEMBER 22 2016 11:41 PM EDT...
Otto strengthens further into a hurricane...and additional strengtheing is expected before Otto makes landfall in southern Nicaragua and Costa Rica later this week. Therefore interests in these areas and offshore southern Caribbean islands should be rushing preparations to completion for a possible severe strike from a strong hurricane. See the special feature section below for additional details on Otto. Visit www.nhc.noaa.gov for up to the minute latest information on Otto...including watches and/or warnings that are currently in effect.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1933Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

...SPECIAL FEATURE...HURRICANE OTTO...
Current Prognosis...While strengthening into a hurricane this past afternoon...the cloud field of Otto expanded...became more symmetric...and took on a large comma shape...and the wind field expanded accordingly. However this evening...the outer cloudiness appears to have eroded due to some intrusion of dry...cold...stable air being driven southward by the large 994 mb frontal cyclone entering the west Atlantic. Very recently...the inner core has re-organized with a strengthening and rather compact circular thunderstorm mass while the outer cloudiness remains weak...and the wind field has shrunken. This might indicate Otto has recently re-organized into a rather compact hurricane tonight. As of 0000Z earlier this evening the center of Otto was beginning a westward drift while passing over 10.5N-80W.

Atmospheric Outlook for the Forecast Period...Otto has finally begun a westward drift while finally becoming steered by the 1031 mb ridge over eastern North America approaching from the northwest. Meanwhile as the large upper trough/surface frontal cyclone over the west Atlantic shifts eastward and away...upper-level winds have become more favorable as the ventilating upper ridge over Otto now has room to re-locate and expand at a position directly on top of the hurricane...espeically while bolstered by the latent heat release of Otto's thundrestorm activity. The westward drift of Otto is expected to remain slow for the next 48 to 72 hours as the 1001 mb frontal cyclone and its upper trough over the central United States weakens the steering 1031 mb ridge. By 96 hours this frontal cyclone will have moved into the Atlantic which will allow the ridge to re-build north of Otto...resutling in a westward acceleration of Otto into the eastern Pacific.

Thermodynamic Outlook for the Forecast Period...Otto will be over favorable 29 deg C waters in the southern Caribbean supportive of tropical development. It appears the large mass of dry..cool...stable air immediately north of the hurricane may not have an effect on the hurricane as the hurricane has recently established a protective tight core of strong thunderstorms per the above current prognosis section.


My (red) track and intensity forecast points in the above graphic:

24 Hr Forecast (0000Z Nov 24)...85 mph maximum sustained wind hurricane centered offshore of Nicaragua and Costa Rica at 10.5N-81.5W

48 Hr Forecast (0000Z Nov 25)...100 mph maximum sustained wind hurricane centered just offshore of Nicaragua and Costa Rica at 10.5N-82.5W

72 Hr Forecast (0000Z Nov 26)...50 mph maximum sustained tropical storm centered over north-central Costa Rica at 10.5N-84.5W

96 Hr Forecast (0000Z Nov 27)...Remnant low centered over the eastern Pacific at 10.5N-87.5W

Track Forecast...Computer models continue to trend with a weaker version of the 1001 mb frontal cyclone currently crossing over the central US. This will allow the steering ridge to the north of Otto to remain stronger and therefore I have upped the westward pace of my forecast track in the 72 to 96 hour timeframe to begin catching up with the latest model guidance. I may have to continue increase the westward pace of the forecast track in later updates.

Intensity Forecast...With Otto remaining a compact tropical cyclone and a history of compact tropical cyclone rapidly intensifying...with warm waters of 29 deg C (thermodynamic outlook section)...and with favorable upper-level winds (atmospheric outlook section)...I continue to forecast Otto to reach category 2 100 mph maximum sustained wind strength before landfall. I also continue to show rapid weakening and dissipation by 96 hours after landfall as compact storms like Otto can rapidly weaken...even over smaller land masses like Central America. However should the westward pace of the track forecast continue to increase...this would allow Otto to reach eastern Pacific waters more quickly and thus Otto might survive its passage over Central America. In such a scenario the National Hurricane Center would retain the name Otto as it moves into the eastern Pacific...and I would continue to issue special feature sections with forecasts on Otto. However should Otto dissipate and then later re-generate in the eastern Pacific...it would be re-named as an eastern Pacific tropical cyclone and I would not be tracking it on this blog.

Impact Forecast...The impact swath in the above forecast graphic is an extrapolation of the 10 PM EDT NHC tropical storm wind field along my forecast track.

2016 Atlantic Hurricane Season Birdseye Discussion #176

By: NCHurricane2009, 7:26 AM GMT on November 22, 2016

...TUESDAY NOVEMBER 22 2016 2:30 AM EDT...
The area of disturbed weather in the southern Caribbean Sea supported by a surface low rapidly develops into strong Tropical Storm Otto. Additional rapid intensification is possible before Otto makes landfall in southern Nicaragua and Costa Rica later this week...therefore interests in these areas and offshore southern Caribbean islands should be preparing now for a possible severe strike from a strong hurricane. See the special feature section below for additional details on Otto. Visit www.nhc.noaa.gov for up to the minute latest information on Otto...including watches and/or warnings that are currently in effect.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1929Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

...SPECIAL FEATURE...TROPICAL STORM OTTO...
Current Prognosis...The surface low that has persisted in the south-central Caribbean Sea has finally strengthened into tropical depression sixteen...and then Tropical Storm Otto...in the last 24 hours. Newly-named Otto appears to already be developing at a brisk pace while already reaching an intensity of 60 mph maximum sustained winds. As of 0000Z earlier this evening the center of Otto was pinwheeling stationary at 10.5N-79W. The thunderstorm activty of Otto is biased to the west of the center as the tropical storm is under light easterly shear while being under the west side of (instead of directly below) the upper ridge that has been ventilating this system over the last few days. The upper ridge has been suppressed to the east of Otto due to strong 986 mb frontal cyclone and its upper trough dominating eastern North America and the west Atlantic.

Atmospheric Outlook for the Forecast Period...Otto is currently stationary while trapped between the westerly steering flow from the upper trough and 986 mb surface frontal cyclone over the western Atlantic and eastern North America...and easterly steering flow of a strong 1030 mb surface ridge over central North America. As the upper trough/surface frontal cyclone shift eastward and away...the current easterly shear regime mentioned in the above current prognosis section should subside as there will be room for the ventilating upper ridge to re-locate and expand over directly over Otto...espeically while bolstered by the latent heat release of Otto's thundrestorm activity. In addition Otto will likely begin moving westward toward Nicaragua and Costa Rica while the 1030 mb ridge shifts to the north of Otto and pushes it. By 48 to 96 hours...a pair of frontal cyclones moving into eastern North America will weaken the ridge which could cause Otto's westward track to slow down. However unlike previous forecasts...I no longer show Otto stalling during this timeframe as the models have trended with weaker frontal cyclones. In fact already by 96 hours the latest model runs show the ridge re-building...and so I have increased the westward pace of my forecast track for the 72 to 96 hour timeframe. I further increase the westward pace under the re-building ridge for the 96 to 120 hour forecast period.

Thermodynamic Outlook for the Forecast Period...Otto will be over favorable 29 deg C waters in the southern Caribbean supportive of tropical development.


My (red) track and intensity forecast points in the above graphic:

24 Hr Forecast (0000Z Nov 23)...70 mph maximum sustained wind tropical storm centered at 10.5N-80.5W

48 Hr Forecast (0000Z Nov 24)...85 mph maximum sustained wind hurricane centered offshore of Nicaragua and Costa Rica at 10.5N-81.5W

72 Hr Forecast (0000Z Nov 25)...100 mph maximum sustained wind hurricane centered just offshore of Nicaragua and Costa Rica at 10.5N-82.5W

96 Hr Forecast (0000Z Nov 26)...100 mph maximum sustained wind hurricane making landfall on the Nicargua/Costa Rica border at 10.5N-83.7W

120 Hr Forecast (0000Z Nov 27)...35 mph maximum sustained wind tropical depression weakening to a remnant low over northwestern Costa Rica coast...centered at 10.5N-85.7W

Track Forecast...Once again I have had to shift my forecast track south and east as Otto continued to shift south and east during its formative stages...likely due to northwesterly flow on the southwest side of the large upper trough/surface frontal cyclonic system that has been over eastern North America/west Atlantic. Per the above atmospheric outlook section...I have incrased the westward pace of Otto for 48 hours and beyond...see atmopsheric outlook section for details.

Intensity Forecast...With Otto becoming a compact tropical cyclone and a history of compact tropical cyclone rapidly intensifying...with warm waters of 29 deg C (thermodynamic outlook section)...and with atmopsheric conditions expected to become even more favorable with a reduction in shear (atmoshperic outlook section)...I have no choice but to raise the intensity forecast especially considering that Otto has jumped well ahead of my previous intensity forecast in the last 24 hours. The intensity forecast in fact may have to be raised even further to show Otto becoming a major hurricane (115+ mph) in the next day or so should signs of rapid development indeed manifest...and therefore interests in southern Nicaragua and Costa Rica should be taking Otto seriously and begin making preparations for a potentially severe strike late this week. Rapid weakening is then shown by 120 hours as compact tropical cyclones tend to rapidly weaken at landfall...even for smaller land masses such as Central America.

Impact Forecast...The impact swath in the above forecast graphic is an extrapolation of the 10 PM EDT NHC tropical storm wind field along my forecast track...with some slight growth in the swath to reflect the anticipated strengthening. The rather small wind field at 10 PM EDT indicates that Otto is structured as a compact tropical cyclone...although it may not seem that way with a field of cloudiness attached to Otto extending to the east-northeast. However note that these clouds are associated with the tail end of cold fronts associated with the large 986 mb frontal cylcone moving into the west Atlantic...and not necessarily associated with the compact tropical storm.

2016 Atlantic Hurricane Season Birdseye Discussion #175

By: NCHurricane2009, 3:16 AM GMT on November 21, 2016

...SUNDAY NOVEMBER 20 2016 10:17 PM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. The area of disturbed weather in the region supported by a surface low continues to become better organized...and conditions will become more favorable for development as the base of the large upper trough over the west Atlantic and eastern North America shifts eastward and away which will allow the overhead upper ridge that is ventilating the surface low to expand. See the special feature section below for additional details on this developing situation. Interests in Nicaragua and Costa Rica should monitor the progress of this disturbance as it could develop into a strong tropical storm or possibly a hurricane while slowly moving toward Central America over the next few days.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1933Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

...SPECIAL FEATURE...CARIBBEAN SURFACE LOW INVEST 90-L...
This special feature section is for area of interest #1 marked in the above atmospheric features chart.

Current Prognosis...The surface low that has persisted in the south-central Caribbean Sea over the last few days continues to become better organized while aided by warm sea surface temperatures and upper-level outflow from an overhead upper ridge. As of 1800Z earlier this afternoon the center of the surface low was pinwheeling stationary at 11.5N-80W and features curved thunderstorm bands around the center. This is slightly east of my previous forecast and therefore I have shifted my track forecast eastward listed below accordingly. I have also raised my intensity forecast as the eastward-adjusted track gives more time for this system to develop over water before making landfall in Central America.

Atmospheric Outlook for the Forecast Period...The surface low is currently stationary while trapped between the westerly steering flow from the upper trough and 985 mb surface frontal cyclone over the western Atlantic and eastern North America...and easterly steering flow of a strong 1032 mb surface ridge over the central North America. As the upper trough/surface frontal cyclone shift eastward and away...the unfavorable westerly vertical shear applied by the base of the upper trough will reduce and the favorable overhead upper ridge will expand. In addition the surface low will likely begin moving westward toward Nicaragua and Costa Rica while the 1032 mb ridge shifts to the north of the surface low and pushes it. By 96 to 120 hours...a pair of frontal cyclones moving into eastern North America will weaken the ridge which could cause the surface low to stall again.

Thermodynamic Outlook for the Forecast Period...The surface low will be over favorable 29 deg C waters in the southern Caribbean supportive of tropical development.

24 Hr Forecast (1800Z Nov 21)...35 mph maximum sustained wind tropical depression centered at 11.5N-80W

48 Hr Forecast (1800Z Nov 22)...50 mph maximum sustained wind tropical storm centered just east of southern Nicaragua at 11.5N-81.5W

72 Hr Forecast (1800Z Nov 23)...70 mph maximum sustained wind tropical storm centered just offshore of southern Nicargua at 11.5N-83W

96 Hr Forecast (1800Z Nov 24)...80 mph maximum sustained wind hurricane centered just offshore of southern Nicaragua at 11.5N-83W

120 Hr Forecast (1800Z Nov 25)...80 mph maximum sustained wind hurricane centered just offshore of southern Nicaragua at 11.5N-83W

2016 Atlantic Hurricane Season Birdseye Discussion #174

By: NCHurricane2009, 10:10 PM GMT on November 19, 2016

...SATURDAY NOVEMBER 19 2016 5:11 PM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. The area of disturbed weather in the region supported by a surface low has already become better organized...and conditions will become more favorable for development as the bases of both the upper troughs in the west Atlantic and eastern North America shift eastward and away which will allow the overhead upper ridge that is ventilating the surface low to expand. Therefore I have upgraded this system to a special feature on this blog with a tropical cyclone formation forecast...see the special feature section below for additional details on this developing situation. Interests in Nicaragua and Costa Rica should monitor the progress of this disturbance as it could develop into a strong tropical storm or possibly a hurricane while slowly moving toward Central America over the next few days.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1200Z and 1329Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

...SPECIAL FEATURE...CARIBBEAN SURFACE LOW INVEST 90-L...
This special feature section is for area of interest #1 marked in the above atmospheric features chart.

Current Prognosis...The surface low that has persisted in the south-central Caribbean Sea over the last few days has finally begun to become better organized while aided by warm sea surface temperatures and upper-level outflow from an overhead upper ridge. As of 1800Z earlier this afternoon the center of the surface low was pinwheeling stationary at 11.5N-81W and features curved thunderstorm bands around the center.

Atmospheric Outlook for the Forecast Period...The surface low is currently stationary while trapped between the westerly steering flow from the upper troughs and 990 mb and 992 mb surface frontal cyclones over the western Atlantic and eastern North America...and easterly steering flow of a strong 1040 mb surface ridge over the central United States. As the pair of upper troughs/surface frontal cyclones shift eastward and away...the unfavorable westerly vertical shear applied by the bases of both upper troughs will reduce and the favorable overhead upper ridge will expand. In addition the surface low will likely begin moving westward toward Nicaragua and Costa Rica while the 1040 mb ridge shifts to the north of the surface low and pushes it. By the end of the 120-hour forecast period...another frontal cyclone moving into eastern North America will weaken the ridge which could cause the surface low to stall again.

Thermodynamic Outlook for the Forecast Period...The surface low will be over favorable 29 deg C waters in the southern Caribbean supportive of tropical development.

24 Hr Forecast (1800Z Nov 20)...Surface low centered at 11.5N-81W

48 Hr Forecast (1800Z Nov 21)...35 mph maximum sustained wind tropical depression centered at 11.5N-81W

72 Hr Forecast (1800Z Nov 22)...50 mph maximum sustained wind tropical storm centered just east of southern Nicaragua at 11.5N-82.5W

96 Hr Forecast (1800Z Nov 23)...70 mph maximum sustained wind tropical storm centered over southeastern Nicaragua at 11.5N-84W

120 Hr Forecast (1800Z Nov 24)...35 mph maximum sustained wind tropical depression centered over southeastern Nicaragua at 11.5N-84W

2016 Atlantic Hurricane Season Birdseye Discussion #173

By: NCHurricane2009, 1:19 AM GMT on November 18, 2016

...THURSDAY NOVEMBER 17 2016 8:20 PM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. The area of disturbed weather in the region supported by a surface low has become less organized as wind shear increases due to the base of the upper trough that has recently entered the west Atlantic from eastern North America. After this upper trough and upper trough currently over the western United States pass by over the next few days...the shear could again relax to allow for tropical cyclone formation. Therefore not currently upgrading this system to a special feature on this blog with a tropical cyclone formation forecast...but will considering doing so should this system further develop in the shear environment or later develop when the shear relaxes again.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1927Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #172

By: NCHurricane2009, 3:19 AM GMT on November 17, 2016

...WEDNESDAY NOVEMBER 16 2016 10:19 PM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. The area of disturbed weather in the region supported by a surface low and upper ridge has not become better organized as wind shear increases due to the base of an upper trough from eastern North America nearing. After this upper trough and upper trough currently moving into western North America pass by over the next few days...the shear could again relax to allow for tropical cyclone formation. Therefore not currently upgrading this system to a special feature on this blog with a tropical cyclone formation forecast...but will considering doing so should this system further develop in the shear environment or later develop when the shear relaxes again.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1932Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #171

By: NCHurricane2009, 6:54 AM GMT on November 16, 2016

...WEDNESDAY NOVEMBER 16 2016 2:00 AM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. The area of disturbed weather in the region supported by a surface trough and upper outflow induced by an upper ridge has further organized into a broad 1009 mb surface low. Conditions could become less favorable for development in the next 24 hours as the base of the upper trough emerging from eastern North America will be nearing and inducing westerly vertical shear. After this upper trough and upper trough currently moving into western North America pass by over the next few days...the shear could again relax to allow for tropical cyclone formation. Therefore not currently upgrading this system to a special feature on this blog with a tropical cyclone formation forecast...but will considering doing so should this system further develop in the shear environment or later develop when the shear relaxes again.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1921Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #170

By: NCHurricane2009, 6:26 AM GMT on November 15, 2016

...TUESDAY NOVEMBER 15 2016 1:27 AM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. Although the thunderstorm activity in the area supported by a surface trough and upper outflow induced by an upper ridge is becoming increaingly organized just east of Nicaragua...conditions could become less favorable for development by 48 hours when the base of the upper trough moving into eastern North America nears the Caribbean and induces westerly vertical shear. The current rate of organization does not appear to be fast enough for tropical cyclone formation before the shear increases by 48 hours. Therefore not currently upgrading this system to a special feature on this blog with a tropical cyclone formation forecast...but will continue to monitor this system and may later upgrade this system to a special feature depending on the evolution of this system as the shear increases.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0231Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #169

By: NCHurricane2009, 2:58 AM GMT on November 14, 2016

...SUNDAY NOVEMBER 13 2016 10:00 PM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. The thunderstorm activity in the area supported by a surface trough and upper outflow induced by an upper ridge is becoming concentrated east of Nicaragua and south of Jamaica. Conditions could become less favorable for development by 72 hours when the base of the upper trough currently over the central United States nears the Caribbean and induces westerly vertical shear. However if current trends continue...I will be upgrading this system to a special feature in my next blog update with a tropical cyclone formation forecast...as a tropical cyclone could form before 72 hours.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1926Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #168

By: NCHurricane2009, 8:29 AM GMT on November 13, 2016

...SUNDAY NOVEMBER 13 2016 3:30 AM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. Although a surface trough has moved into this area...the thunderstorm activity in the region supported by enhanced upper outflow from an amplified upper ridge has decreased and remains poorly-organized. Therefore I have not yet upgraded this area of disturbed weather to a special feature with a tropical cyclone formation forecast even though computer model support for tropical cyclone development remains high. However will continue to monitor this area carefully over the next few days.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0128Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #167

By: NCHurricane2009, 7:59 AM GMT on November 12, 2016

...SATURDAY NOVEMBER 12 2016 3:00 AM EDT...
The following statement concerns area of interest #1 marked in the central Caribbean Sea in the atmospheric features chart below. The surface low in the eastern Caribbean has weakened into a surface trough...but is approaching an area of increasing thunderstorm activity in the central Caribbean boosted by enhanced upper outflow from an amplifying upper ridge. Therefore tropical cyclone formation will be possible over the next few days as the surface trough moves into the central Caribbean.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0133Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #166

By: NCHurricane2009, 7:51 AM GMT on November 11, 2016

...FRIDAY NOVEMBER 11 2016 2:52 AM EDT...
The following statement concerns area of interest #1 marked in the western Atlantic in the atmospheric features chart below. As expected a portion of the shortwave upper trough and surface frontal system that recently emerged from eastern North America has amplified into a deep-layered frontal cyclonic system while diving into the western Atlantic longwave upper trough regime that has persisted over the last several days. There is a lack of thunderstorm activity near this frontal cyclone's center...and tropical development is not expected as it will quickly become absorbed by the 982 mb frontal cyclone fast approaching from eastern Canada. This is my final statement on this system on this blog.

The following statement concerns area of interest #2 marked in the eastern Caribbean Sea in the atmospheric features chart below. A review of satellite imagery over the last few days suggests a weak tropical wave has evolved into a small surface tropical low while moving into the Caribbean Sea. This system may develop as it moves into the central Caribbean Sea under a low shear and enhanced upper outflow environment developing in the region as upper ridging is amplifying. Therefore will watch this system over the next few days.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1947Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #165

By: NCHurricane2009, 1:12 AM GMT on November 10, 2016

...WEDNESDAY NOVEMBER 9 2016 8:14 PM EDT...
The following statement concerns area of interest #1 marked just offshore of the Carolinas in the atmospheric features chart below. A shortwave upper trough currently emerging into the western Atlantic from eastern North America is supporting a lengthy surface frontal system...and in the next 24 hours the portion of this weather system currently offshore of the Carolinas is expected to amplify into a cut-off frontal cyclonic system while diving into the western Atlantic longwave upper trough regime that has persisted over the last several days. However the latest model runs show that another frontal system coming from Canada is likely to quickly absorb any frontal cyclonic system that develops before it can acquire tropical characteristics. Will continue to monitor this situation in case model solutions change again.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1931Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #164

By: NCHurricane2009, 2:58 AM GMT on November 09, 2016

...TUESDAY NOVEMBER 8 2016 10:05 PM EDT...
The following statement concerns area of interest #1 marked over the western Atlantic just northeast of Bermuda in the atmospheric features chart below. The deep-layered frontal cyclone in the area has not acquired additional tropical characteristics. This system will be accelerated northeastward into even cooler waters southeast of Atlantic Canada by the upper trough and surface frontal system approaching from eastern North America...therefore subtropical cyclone formation is not expected. This is my final statement on this system on this blog.

The following statement concerns area of interest #2 marked over the central United States in the atmospheric features chart below. A shortwave upper trough currently over eastern North America is supporting a lengthy surface frontal system...and in 48 hours the portion of this weather system currently over the central United States could amplify into a cut-off frontal cyclonic system while diving into the western Atlantic longwave upper trough regime that has persisted over the last several days. However the latest model runs show that another frontal system coming from Canada is likely to quickly absorb any frontal cyclonic system that develops. Will continue to monitor this situation in case model solutions change again.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1928Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #163

By: NCHurricane2009, 2:05 AM GMT on November 08, 2016

...MONDAY NOVEMBER 7 2016 9:05 PM EDT...
A pattern supporting a series of frontal disturbances that could acquire tropical characteristics to persist in the western Atlantic over the next several days...resuming daily updates on the Atlantic tropics on this blog...

The following statement concerns area of interest #1 marked over the western Atlantic just north of Bermuda in the atmospheric features chart below. Over the last 48 hours...a surface frontal depression and its associated shortwave upper trough from eastern Canada has dived southeastward into the longwave western Atlantic upper trough regime that has persisted over the last several days. The shortwave upper trough has amplified into a cut-off upper vortex during this process...with stronger upper divergence on the east side of the amplifying upper feature causing the surface frontal depression to rapidly strengthen into a 1002 mb frontal cyclone located just north of Bermuda. Even though the frontal cyclone is currently just northeast of warm 26 deg C waters typically supportive of tropical development...increasingly organizing showers and thunderstorms have fired around and close to the center due to de-stabilizing cold temperatures of the overhead cut-off upper vortex. Although I will watch for the development of subtropical characteristics from this frontal cyclone in the next 24 hours...by 48 hours it will be accelerated northeastward into even cooler waters southeast of Atlantic Canada by the upper trough and surface frontal system approaching from central North America...and so subtropical cyclone formation does not appear likely at the moment.

The following statement concerns area of interest #2 marked over the central United States in the atmospheric features chart below. A shortwave upper trough currently over central North America is supporting a lengthy surface frontal system...and in 72 hours the portion of this weather system currently over the central United States could amplify into a cut-off frontal cyclonic system while diving into the western Atlantic longwave upper trough regime that has persisted over the last several days. At this time it appears such a frontal cyclone would form over sufficiently warm waters over or near Bermuda to potentially acquire subtropical characteristics. Therefore will also monitor the progress of this frontal system over the next few days.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1918Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #162

By: NCHurricane2009, 11:44 PM GMT on November 05, 2016

...SATURDAY NOVEMBER 5 2016 7:44 PM EDT...
The following statement concerns area of interest #1 marked over the north-central Atlantic in the atmospheric features chart below. The broad surface low that was in the central Atlantic has not transitioned into a subtropical cyclone as its supporting upper trough from the western Atlantic has not closed off into an upper vortex. This surface low has already moved into cooler north-central Atlantic waters and will not acquire tropical characteristics.

It is quiet elsewhere in the Atlantic tropics. This will be my final blog update until the potential for tropical development returns to the Atlantic basin.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1925Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #161

By: NCHurricane2009, 10:36 PM GMT on November 03, 2016

...THURSDAY NOVEMBER 3 2016 6:37 PM EDT...
The following statement concerns area of interest #1 marked over the central Atlantic in the atmospheric features chart below. The broad surface low in this area continues to become enhanced by divergence on the east side of an upper trough in the western Atlantic. The upper trough is not expected to become a cut-off upper vortex such that the surface low moves faster to the northeast into cooler waters...making it unlikely that this system becomes a subtropical cyclone. Therefore I will stop mentioning this system on this blog once it becomes removed from the National Hurricane Center tropical weather outlook.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1923Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #160

By: NCHurricane2009, 3:05 AM GMT on November 03, 2016

...WEDNESDAY NOVEMBER 2 2016 11:05 PM EDT...
The following statement concerns area of interest #1 marked over the central Atlantic in the atmospheric features chart below. The broad surface low in this area continues to become enhanced by divergence on the east side of an upper trough fragment in the western Atlantic. However most of the latest model runs continue to back off on the solution where the upper trough fragment becomes a cut-off upper vortex such that the surface low moves faster to the northeast into cooler waters...making it less likely that this system becomes a subtropical cyclone. However will continue to monitor this area in case model solutions change again.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1928Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #159

By: NCHurricane2009, 1:53 AM GMT on November 02, 2016

...TUESDAY NOVEMBER 1 2016 9:54 PM EDT...
The following statement concerns area of interest #1 marked over the western Caribbean Sea and Yucatan peninsula in the atmospheric features chart below. Although thunderstorm activity in this region persists...the associated surface trough is not showing signs of consolidating into a surface low pressure spin. Less favorable westerly vertical shear is likely to increase in 72 to 96 hours as the base of the strong upper trough currently over western North America nears and therefore it is becoming less likely that this system will consolidate and develop into a tropical cyclone before the shear increases. Therefore this is my final statement on this system on this blog.

The following statement concerns area of interest #2 marked over the northeastern Caribbean Islands (Puerto Rico...Virgin Islands...and northern Lesser Antilles) and central tropical Atlantic. The broad surface low in this area is becoming enhanced by the southern fracture of the upper trough currently over the western Atlantic...resulting in a much larger area of thunderstorms that extends into the central Atlantic. However most of the latest model runs continue to back off on the solution where the fracture becomes a cut-off upper vortex such that the surface low moves faster to the northeast into cooler waters...making it less likely that this system becomes a subtropical cyclone. However will continue to monitor this area in case model solutions change again.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1953Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).

2016 Atlantic Hurricane Season Birdseye Discussion #158

By: NCHurricane2009, 10:19 AM GMT on November 01, 2016

...TUESDAY NOVEMBER 1 2016 6:20 AM EDT...
The following statement concerns area of interest #1 marked over the western Caribbean Sea...Nicaragua...and Honduras in the atmospheric features chart below. Although thunderstorm activity in this region has continued to expand and now covers parts of Nicaragua and Honduras...the surface low in the area has not consolidated and is now a broad surface trough. However will continue to monitor this area for a couple more days until the vertical shear becomes unfavorably higher for tropical development.

The following statement concerns area of interest #2 marked over the northeastern Caribbean Islands (Puerto Rico...Virgin Islands...and northern Lesser Antilles). The surface low in this area will become enhanced by a southern fracture of the upper trough currently over the western Atlantic. Most of the latest model runs have backed off the solution where the fracture becomes a cut-off upper vortex such that the surface low moves faster to the northeast into cooler waters which makes it less likely that this system becomes a subtropical cyclone. However will continue to monitor this area in case model solutions change again.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0600Z and 0715Z-released WPC analysis.

Areas of Interest maybe first introduced circled by a yellow-dashed line. If the area of interest becomes introduced in the 5-day National Hurricane Center (NHC) Atlantic tropical weather outlook then it gets upgraded with a green-dashed line encircling it. If the area of interest gets upgraded to an Invest or is mentioned in the 48-hour NHC Atlantic tropical weather outlook then it gets upgraded with a green-solid polygon encircling it.

In light blue is upper air analysis, with 200 mb wind barbs calculated by GOES satellite imagery showing the upper-level wind direction. Based on the 200 mb wind barbs, blue-dashed lines are locations of upper troughs, blue-zig-zag lines are locations of upper ridges. Blue Ls are locations of upper lows (also called an upper vortex or upper cyclone), blue Hs are locations of upper ridges (also called upper anticyclones).

In red is surface analysis, with solid lines indicating locations of surface fronts, dashed lines indicating locations of surface troughs, and zig-zag lines indicating surface ridge axes. Surface troughs labeled with TW indicates the trough is a tropical wave whose origin is from the mid-level African Easterly Jet. Ls indicate surface lows (cyclones), Hs indicate surface highs (ridges/anticyclones).

...THERMODYNAMICS BIRDSEYE CHART...

This chart is generated using GOES water vapor satellite imagery. Brown indicates dry air. White, blue, and purple indicates moist air. An increase in moisture indicates slower air parcel lapse rates with elevation and hence an increase toward instability.

Sea-surface temperatures are overlaid with light blue isotherms. The 26 deg C isotherm is highlighted in red. Waters at and south of the 26 deg C isotherm indicate low-level warmth and hence faster environmental lapse rates with elevation (more instability). Waters north of the 26 deg C isotherm indicate slower environmental lapse rates with elevation (less instability).


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

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