NCHurricane2009's Blog

2016 Atlantic Hurricane Season Birdseye Discussion #75

By: NCHurricane2009, 8:24 AM GMT on July 31, 2016

...SUNDAY JULY 31 2016 4:25 AM EDT...
The following statement concerns area of interest #1 marked over the central tropical Atlantic in the atmospheic features chart below. Tropical wave Invest 97-L continues to become better organized while moving briskly into the eastern Caribbean islands...and tropical cyclone formation is likely as this wave moves across the Caribbean over the next few days. Regardless of development...the Lesser Antilles...Puerto Rico...Hispaniola (Haiti and the Dominican Republic)...eastern Cuba...Jamaica...the Cayman Islands...and the Yucatan peninsula of southeastern Mexico can expect squally vigorous weather from this system over the next few days...and these areas should monitor the progress of this tropical wave. See first special feature section below for additional details.

The following statement concerns area of interest #2 marked over the eastern tropical Atlantic in the atmospheric features chart below. Tropical wave Invest 96-L remains has become less organized but tropical cyclone formation remains possible as it moves into the central tropical Atlantic. See second special feature section below for additional details.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0122Z-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...CENTRAL ATLANTIC TROPICAL WAVE INVEST 97-L...
This special feature section is for area of interest #1 marked in the above atmospheric features chart.

Current Prognosis...Tropical wave Invest 97-L continues to move briskly westward while steered by the 1029 mb surface ridge currently in the Atlantic...and is crossing 60W longitude early this morning. The associated shower and thunderstorm activity has continued to become better organized into spiral bands and already has the appearance of a tropical cyclone...but the National Hurricane Center states that this system is not yet a tropical cyclone while lacking a closed surface circulation at this time. This system is producing squally weather across the Lesser Antilles and Virgin Islands...and will soon spread into Puerto Rico later this morning. Afterwards Hispaniola (Haiti and the Dominican Republic)...eastern Cuba...Jamaica...the Cayman Islands...and Yucatan peninsula of southeastern Mexico over the next few days. These areas should monitor the progress of this tropical wave.

Atmospheric Outlook for the Forecast Period...During the first 48 hours computer models agree that this tropical wave will continue briskly westward while continuing to be steered by the 1029 mb Atlantic surface ridge. After that time the tropical wave is expected to slow down while arriving into the western Caribbean as it reaches weaker steering on the southwest edge of the aforementioned surface ridge. The upper vorticity that was previously strung across the eastern Caribbean and central Atlantic has begun to split into one upper vortex over the western Bahamas and another upper vortex over the central Atlantic...with a favorable upper anticyclone developing between these two upper vortices and over this tropical wave. During the later part of forecast period the tropical wave will pass south of the unfavorable western Bahamas upper vortex and reach the favorable upper anticyclone that is currently centered over the Gulf of Mexico. Even though this tropical wave is poised to stay under favorable upper anticyclones thru the forecast period...tropical cyclone formation is not likely until 72 hours. This is because the current rapid westward pace makes it more challenging for the tropical wave to develop a fully-closed surface circulation. However given the current organization of this system...I have increased the intensity forecast for what is currently the 72 to 120 hour forecast period. I have also slightly shifted the forecast track northward since current organization suggests the circulation is already at 15N latitude.

Thermodynamic Outlook for the Forecast Period...On the forecast track shown below...this tropical wave will track over favorable 29 to 31 deg C waters. As shown by the recent increase in organization...this tropical wave has survived its passage across dry saharan air in the central tropical Atlantic and will reach a more favorable moist atmosphere in the Caribbean currently seen in the latest water vapor imagery.

24 Hr Forecast (0000Z Aug 1)...Tropical wave along 68W longitude in the eastern Caribbean Sea

48 Hr Forecast (0000Z Aug 2)...Tropical wave along 77W longitude in the central Caribbean Sea

72 Hr Forecast (0000Z Aug 3)...35 mph maximum sustained wind tropical depression centered at 17.5N-82W in the western Caribbean Sea

96 Hr Forecast (0000Z Aug 4)...45 mph maximum sustained wind tropical storm centered at 18.5N-87W approaching the Yucatan peninsula of southeastern Mexico

120 Hr Forecast (0000Z Aug 5)...35 mph maximum sustained wind tropical depression centered at 19.5N-91W emerging into the western Gulf of Mexico from the northwestern Yucatan peninsula

...SPECIAL FEATURE...EASTERN ATLANTIC TROPICAL WAVE INVEST 96-L...
This special feature section is for area of interest #2 marked in the above atmospheric features chart.

Current Prognosis...Tropical wave Invest 96-L is currently southwest of the Republic of Cabo Verde and passed 30W longitude as of 0000Z earlier this evening. The low pressure spin is further south and also less organized...and therefore my updated forecast track is further south and updated forecast intensity is lowered. Based on the fact that most of the thunderstorm activity is now south of the low pressure center...this suggests the inverted upper trough just northwest of the tropical wave is supressing the north half of the tropical wave at this time.

Atmospheric Outlook for the Forecast Period...Thru the forecast period this tropical wave is expected to continue westward while steered by the 1029 mb surface ridge currently firmly in place across the Atlantic. To keep up with the latest model runs and because Invest 97-L to its west ended up accelerating westward...I have upped the forecast westward pace of this tropical wave to be faster in the later part of the forecast period. The unfavorfable inverted upper trough to the northwest (mentioned in the above current prognosis section) is still expected to move westward and away while an upper ridge from the eastern tropical Atlantic expands over the tropical wave....potentially allowing this tropical wave to develop under low shear and good upper outflow beneath the more favorable upper ridge. Meanwhile...upper vorticity that was strung across the eastern Caribbean and central Atlantic has begun to split into two upper vortices...with the eastern one potentially producing some less favorable southerly vertical when this tropical wave arrives to the central Atlantic. However with the southward adjusted forecast track and latest model runs showing this upper vortex staying further north...my current forecast assumes this upper vortex will not be much of a factor in affecting development.

Thermodynamic Outlook for the Forecast Period...The forecast track shown below will keep this tropical wave over favorable 28 deg C waters. Water vapor imagery over the last 48 hours suggests a swath of dry saharan air nosing southward into the future path of this tropical wave...and therefore another reason I have lowered the intensity forecast is due to potential ingestion of this dry air.

24 Hr Forecast (0000Z Aug 1)...Tropical low centered at 12N-34.5W

48 Hr Forecast (0000Z Aug 2)...30 mph maximum sustained wind tropical depression centered at 12N-39W

72 Hr Forecast (0000Z Aug 3)...40 mph maximum sustained wind tropical storm centered at 12.5N-43.5W

96 Hr Forecast (0000Z Aug 4)...45 mph maximum sustained wind tropical storm centered at 13N-49W

120 Hr Forecast (0000Z Aug 5)...50 mph maximum sustained wind tropical storm centered at 13.5N-56W approaching the southern Lesser Antilles

2016 Atlantic Hurricane Season Birdseye Discussion #74

By: NCHurricane2009, 8:07 AM GMT on July 30, 2016

...SATURDAY JULY 30 2016 4:08 AM EDT...
The following statement concerns area of interest #1 marked over the central tropical Atlantic. Tropical wave Invest 97-L has become better organized while accelerating briskly from the waters west-southwest of the Republic of Cabo Verde and into the central tropical Atlantic over the last 24 hours. Over the next 24 hours this tropical wave is likely to bring vigorous weather to the Lesser Antilles and northeastern Caribbean Sea islands. The current brisk westward track will allow it to phase with favorable upper winds...and most computer models now agree that this tropical wave is likely to develop while reaching the western Caribbean...Yucatan peninsula of southeastern Mexico...and eventually the western Gulf of Mexico. Therefore I have upgraded this tropical wave to a special feature...see first special feature section below for additional details.

The following statement concerns area of interest #2 marked over the eastern tropical Atlantic. Tropical wave Invest 96-L remains well-organized and tropical cyclone formation remains possible as it moves into the central tropical Atlantic. See second special feature section below for additional details.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0123Z-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...CENTRAL ATLANTIC TROPICAL WAVE INVEST 97-L...
This special feature section is for area of interest #1 marked in the above atmospheric features chart.

Current Prognosis...While encountering some strong steering on the south side of the 1030 mb ridge across the Atlantic...tropical wave Invest 97-L has briskly accelerated into the central tropical Atlantic and is passing 50W longitude early this morning. The associated shower and thunderstorm activity has become better organized over the last 24 hours into curved bands of thunderstorms across the north half of the wave axis.

Atmospheric Outlook for the Forecast Period...During the first 72 hours computer models agree that this tropical wave will continue briskly westward while continuing to be steered by the 1030 mb Atlantic surface ridge. After that time the tropical wave is expected to slow down while arriving into the western Caribbean as it reaches weaker steering on the southwest edge of the aforementioned surface ridge. Upper vorticity continues to linger to the northwest of the tropical wave...across the eastern Caribbean and central Atlantic. This upper vorticity is expected to split into one upper vortex over the western Bahamas and another over the central Atlantic. However at the current westward pace...it is now apparent that the tropical wave will become phased with a favorable upper anticyclone to develop between the upper vortices...and by the end of the forecast period the tropical wave will pass south of the unfavorable western Bahamas upper vortex and reach the favorable upper anticyclone that is currently centered over the Florida peninsula. Even though this tropical wave is poised to stay under favorable upper anticyclones thru the forecast period...tropical cyclone formation is not likely until the late part or just after the 120-hour forecast period when it slows down. This is because the rapid westward pace makes it more challenging for the tropical wave to devlop a fully-closed surface circulation.

Thermodynamic Outlook for the Forecast Period...On the forecast track shown below...this tropical wave will track over favorable 29 to 31 deg C waters. As shown by the recent increase in organization...this tropical wave has survived its passage across dry saharan air in the central tropical Atlantic and will reach a more favorable moist atmosphere in the Caribbean currently seen in the latest water vapor imagery.

24 Hr Forecast (0000Z Jul 31)...Tropical wave along 59W longitude approaching the Lesser Antilles

48 Hr Forecast (0000Z Aug 1)...Tropical wave along 68W longitude in the eastern Caribbean Sea

72 Hr Forecast (0000Z Aug 2)...Tropical wave along 77W longitude in the central Caribbean Sea

96 Hr Forecast (0000Z Aug 3)...Tropical wave along 82W longitude in the western Caribbean Sea

120 Hr Forecast (0000Z Aug 4)...Organizing tropical low centered at 17.5N-87W approaching Belize and Yucatan peninsula of southeastern Mexico

...SPECIAL FEATURE...EASTERN ATLANTIC TROPICAL WAVE INVEST 96-L...
This special feature section is for area of interest #2 marked in the above atmospheric features chart.

Current Prognosis...Tropical wave Invest 96-L has passed south of the Republic of Cabo Verde in the last 24 hours and continues to produce an organized low pressure spin. As of 0000Z earlier this evening the low pressure spin was centered at 12N-25.5W based on satellite imagery. This is slighlty south of my previous forecast and therefore my updated forecast track listed below is adjusted accordingly.

Atmospheric Outlook for the Forecast Period...Thru the forecast period this tropical wave is expected to continue westward while steered by the 1030 mb surface ridge currently firmly in place across the Atlantic. Although an unfavorfable inverted upper trough has formed just northwest of the tropical wave...the inverted upper trough is expected to move westward and away around the south side of the upper anticyclone in the eastern Atlantic...potentially allowing this tropical wave to develop under low shear and good upper outflow beneath the more favorable upper anticyclone. To the northwest of the anticyclone...upper vorticity lingering across the eastern Caribbean and central Atlantic is expected to split into two upper vortices...with the eastern one potentially applying some southerly vertical shear to this tropical wave when it arrives to the central tropical Atlantic in 72 to 96 hours. Therefore I have lowered my intensity forecast for that timeframe. By 120 hours this upper vortex is currently forecast to shift north enough such that conditions become more favorable again.

Thermodynamic Outlook for the Forecast Period...The forecast track shown below will keep this tropical wave over favorable 27 deg C waters. Latest water vapor imagery suggests this tropical wave is embedded in a large moisture field and therefore my forecast below currently assumes dry saharan air in the central Atlantic will not be much of a factor in affecting development.

24 Hr Forecast (0000Z Jul 31)...35 mph maximum sustained wind tropical depression centered at 12.5W-30W

48 Hr Forecast (0000Z Aug 1)...45 mph maximum sustained wind tropical storm centered at 13N-34.5W

72 Hr Forecast (0000Z Aug 2)...50 mph maximum sustained wind tropical storm under southerly vertical shear centered at 13.5N-39W

96 Hr Forecast (0000Z Aug 3)...60 mph maximum sustained wind tropical storm under light southerly vertical shear centered at 14N-43.5W

120 Hr Forecast (0000Z Aug 4)...70 mph maximum sustained wind tropical storm centered at 14.5N-48W

2016 Atlantic Hurricane Season Birdseye Discussion #73

By: NCHurricane2009, 4:37 AM GMT on July 29, 2016

...FRIDAY JULY 29 2016 12:40 AM EDT...
The following statement concerns area of interest #1 marked over the eastern tropical Atlantic to the west-southwest of the Republic of Cabo Verde in the atmospheric features chart below. Although the tropical wave in this area of interest has developed a 1011 mb low pressure spin and was upgraded to Invest 97-L in the last 24 hours...recently its showers and thunderstorms have become less organized while battling some easterly vertical shear on the south side of an upper ridge and dry sahran air in the central/eastern tropical Atlantic. The upper wind forecasts are also not favorable while showing unfavorable upper vorticity currently over the central tropical Atlantic lingering at a more south location and affecting this tropical wave as it eventually approaches the Lesser Antilles and eastern Caribbean Sea. Therefore development of this tropical wave is not likely in the next few days.

The following statement concerns area of interest #2 marked over western Africa and far eastern tropical Atlantic in the atmospheric features chart below. Tropical wave Invest 96-L which recently emerged from Africa in the last day is become increasingly organized over the last 24 hours and has been upgraded to a special feature on this blog while at elevated risk of tropical cyclone formatoin. See special feature section below for additional details.

...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...EASTERN ATLANTIC TROPICAL WAVE INVEST 96-L...
This special feature section is for area of interest #2 marked in the above atmospheric features chart.

Current Prognosis...A tropical wave which has recently emerged from western Africa into the eastern tropical Atlantic is producing an organizing tropical low pressure spin with thunderstorms. As of 0000Z earlier this evening the tropical low was centered at 12N-21W. Twenty-four hours ago satellite imagery suggested the tropical low was located at 17.5W longitude...and therefore my forecast below is based on this tropical wave moving at its current 4.5W per 24 hour pace.

Atmospheric Outlook for the Forecast Period...Thru the forecast period this tropical wave is expected to continue westward while steered by the 1031 mb surface ridge currently firmly in place across the Atlantic. The cut-off upper trough currently in the northeast Atlantic is splitting the upper ridge in the eastern Atlantic into two upper anticyclones...the eastern one over Africa...and the western one marked by a blue H to the northwest of this tropical wave in the above atmopsheric features chart. A less favorable inverted upper trough is likely to form between the two upper anticyclones and just to the northwest of this tropical wave...which is why I delay forecast tropical cyclone formation to 48 hours. The inverted upper trough is then forecast to move westward and away around the south side of the upper anticyclone while dissipating...allowing this tropical wave to develop under low shear and good upper outflow beneath the more favorable upper anticyclone.

Thermodynamic Outlook for the Forecast Period...The forecast track shown below will keep this tropical wave over favorable 27 deg C waters. The vigorous tropical wave to the west (Invest 97-L/area of interest #1) is helping to moisten out some of the dry Saharan air in the central tropical Atlantic that lies ahead...and therefore my forecast below assumes that the dry air will not inhibit devleopment of this tropical wave.

24 Hr Forecast (0000Z Jul 30)...Tropical low centered southwest of the Republic of Cabo Verde centered at 13N-25.5W

48 Hr Forecast (0000Z Jul 31)...35 mph maximum sustained wind tropical depression centered at 13.5W-30W

72 Hr Forecast (0000Z Aug 1)...45 mph maximum sustained wind tropical storm centered at 14N-34.5W

96 Hr Forecast (0000Z Aug 2)...60 mph maximum sustained wind tropical storm centered at 15N-39W

120 Hr Forecast (0000Z Aug 3)...70 mph maximum sustained wind tropical storm centered at 16N-43.5W

2016 Atlantic Hurricane Season Birdseye Discussion #72

By: NCHurricane2009, 3:55 AM GMT on July 28, 2016

...WEDNESDAY JULY 27 2016 11:56 PM EDT...
The following statement concerns area of interest #1 marked over the eastern tropical Atlantic to the southwest of the Republic of Cabo Verde in the atmospheric features chart below. The vigorous tropical wave that was south of the Republic of Cabo Verde is now southwest of the Republic. Once again the upper wind forecasts have returned to a less favorable setting...showing unfavorable upper vorticity currently over the central tropical Atlantic lingering at a more south location and affecting this tropical wave as it eventually approaches the Lesser Antilles and eastern Caribbean Sea. In addition their remains unfavorable dry saharan air in the central tropical Atlantic in the immediate path of this tropical wave...and furthermore this tropical wave has become less organized under some easterly vertical shear caused by a developing jet on the south side of the upper ridge currently in the eastern Atlantic. Therefore development of this tropical wave is not likely in the next few days.

The following statement concerns area of interest #2 marked over western Africa and far eastern tropical Atlantic in the atmospheric features chart below. Another vigorous but more impressive tropical wave is emerging into the eastern tropical Atlantic and has been upgraded to Invest 96-L on the Naval Research Laboratory (NRL) site of the US Navy because it displays an organized low pressure spin. Its chances of development are higher than the tropical wave in area of interest #1 as that wave is moistening out the dry saharan air currently present in the central Atlantic. However I am currently hesitant to upgrade this tropical wave to a special feature on this blog as there are early signs of some easterly vertical shear being induced by a developing jet on the south side of the upper ridge currently in the eastern Atlantic...and it is possible this tropical wave gets entangled with the wave in area of interest #1 immediately to its west in which case it could become less organized while becoming a much larger...less-focused disturbance. Should this tropical wave show signs of remaining localized and becoming more organized in the next 24 hours...I will be upgrading to a special feature in my next blog update (featuring a forecast for tropical cyclone formation).

...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).

2016 Atlantic Hurricane Season Birdseye Discussion #71

By: NCHurricane2009, 3:01 AM GMT on July 27, 2016

...TUESDAY JULY 26 2016 11:02 PM EDT...
The following statement concerns area of interest #1 marked over the northwestern Gulf of Mexico...southern Mississippi...and Louisiana marked in the atmospheric features chart below. The inverted upper trough in the northern Gulf of Mexico region continues westward around the south side of a strong upper ridge over the United States. This upper ridge has been split into two upper anticyclones by the inverted upper trough...with divergence between the eastern anticyclone and inverted upper trough supporting showers and thunderstorms over Louisiana and Mississippi...and divergence between the western anticyclone and inverted upper trough producing some activity over the northwestern Gulf and far to the southwest over the Texas/Mexico border. Interaction with land continues to prevent tropical cyclone formation...and only some additional showers and thunderstorms are expected over southern Mississippi...Louisiana...and the southeastern half of Texas.

The following statement concerns area of interest #2 marked over the eastern tropical Atlantic in the atmospheric features chart below. The vigorous tropical wave with low pressure spin that was over the west coast of Africa last evening is now passing south of the Republic of Cabo Verde. The upper wind forecast for the timeframe that is the next 120 hours has improved for tropical development as the unfavorable upper vorticity in the central Atlantic is shown lifting more northward and out of the way of the path of this tropical wave. However there remains unfavorable dry saharan air in the central Atlantic and computer models continue to not forecast tropical cyclone formation. Regardless...should this tropical wave show signs of organizing further I will be upgrading it to a special feature on this blog.

The following statement concerns area of interest #3 marked over western Africa in the atmospheric features chart below. Another vigorous but more impressive tropical wave is about to emerge into the eastern tropical Atlantic where it will be introduced to favorable conditions beneath an upper ridge persisting in the region. Even though the latest computer model runs also do not show this wave developing...its chances of development are higher than the tropical wave in area of interest #2 if that wave moistens out some of the dry saharan air currently present in the central Atlantic. Should this tropical wave show signs of organizing further I will be upgrading it to a special feature on this blog.

...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).

2016 Atlantic Hurricane Season Birdseye Discussion #70A (Special Update)

By: NCHurricane2009, 9:26 PM GMT on July 26, 2016

...TUESDAY JULY 26 2016 5:27 PM EDT...
Showers and thunderstorms have increased near the center of circulation associated with the tropical disturbance in the northern Gulf of Mexico...resulting in showers and thunderstorms spreading into Louisiana...southern Mississippi...and southern Alabama. Therefore in addition to eastern Texas...the risk of isolated flash flooding is possible across these regions. Tropical cyclone formation is still not expected due to the disturbance interacting with land.

My next full blog update on this disturbance and the rest of the Atlantic tropics will follow late this evening or early tomorrow morning.

2016 Atlantic Hurricane Season Birdseye Discussion #70

By: NCHurricane2009, 3:15 AM GMT on July 26, 2016

...MONDAY JULY 25 2016 11:16 PM EDT...
The following statement concerns area of interest #1 marked over the Gulf of Mexico and eastern Texas in the atmospheric features chart below. A cut-off upper vortex orginating from a frontal system and upper trough that emerged from North America on July 20 has retrograded westward into the northern Gulf of Mexico while steered by the south side of a strong upper ridge over the United States associated with a recent heat wave. Divergence between the west side of the retrograding upper vortex and south side of the upper ridge has generated a 1015 mb surface low with widespread showers and thunderstorms across the Gulf of Mexico and eastern Texas over the last 48 hours. Recently the upper vortex has weakened into an inverted upper trough...marked as a blue-dashed line immediately to the right of the 1015 mb surface low. As the inverted upper trough continues westward...this disturbance is expected to move into eastern Texas in the next 48 hours. Tropical cyclone formation out of the 1015 mb surface low is not likely due to land interaction...as it tracks close to the Lousiana and Texas coast before landfall. Regardless of additional development or not...heavy rainfall with isolated flash flooding is possible across eastern Texas in the next day or so.

The following statement concerns area of interest #2 marked over western Africa and the far eastern tropical Atlantic in the atmospheric features chart below. A vigorous tropical wave with a low pressure spin has arrived to the west coast of Africa...and will emerge into the tropical Atlantic in the next 48 hours. Although atmospheric conditions will be favorable due to an upper ridge currently in the eastern tropical Atlantic...the latest computer model runs only show the development of a tropical low instead of a tropical cyclone...perhaps as the dry Saharan air currently in the central tropical Atlantic impedes development. In addition...some of the unfavorable upper vorticity currently in the central tropical Atlantic may linger and affect this system after a few days.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0126Z-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 #69A (Special Update)

By: NCHurricane2009, 10:56 PM GMT on July 25, 2016

...MONDAY JULY 25 2016 7:00 PM EDT...
A tropical disturbance has been developing across the Gulf of Mexico over the last 48 hours...featuring a broad surface spin across the northern Gulf with an increasingly larger and stronger area of showers and thunderstorms sheared to the south of the spin. This area of disturbed weather is being supported by upper divergence between the west side of a decaying cut-off upper vortex that has entered the northeastern Gulf of Mexico and south side of an upper ridge over the United States. Further details including a discussion of its potential for tropical cyclone formation will follow in my next full blog update late tonight/early tomorrow morning.

2016 Atlantic Hurricane Season Birdseye Discussion #69

By: NCHurricane2009, 5:54 AM GMT on July 25, 2016

...MONDAY JULY 25 2016 1:54 AM EDT...
The following statement concerns area of interest #1 marked over the eastern tropical Atlantic to the southwest of the Republic of Cabo Verde in the atmospheric features chart below. A large area of showers and thunderstorms continues as a surface tropical low interacts with upper divergence on the south side of an upper ridge in the eastern tropical Atlantic. However the activity is decreasing as this disturbance ingests dry saharan air in the central tropical Atlantic and begins interacting with less favorable upper vorticity diving southwestward from the northeastern Atlantic. Therefore this is the final statement on this blog concerning this disturbance.

The following statement concerns area of interest #2 marked over western Africa in the atmospheric features chart below. A vigorous tropical wave is expected to emerge from western Africa and into the eastern tropical Atlantic in 96 hours (4 days)...with the possibility of development into a tropical cyclone due to favorable atmospheric conditions supplied by the upper ridge currently in the eastern tropical Atlantic and also as the disturbance to its west (area of interest #1) helps moisten out some of the unfavorable dry Saharan air in the central tropical Atlantic. However the latest computer model runs have backed off in showing development of this tropical wave.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0126Z-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 #68

By: NCHurricane2009, 1:15 AM GMT on July 24, 2016

...SATURDAY JULY 23 2016 9:17 PM EDT...
The following statement concerns area of interest #1 marked over the eastern tropical Atlantic to the southwest of the Republic of Cabo Verde in the atmospheric features chart below. A large area of showers and thunderstorms continues as a surface tropical low (left behind by a tropical wave) interacts with upper divergence on the south side of an upper ridge in the eastern tropical Atlantic. However the activity is decreasing as this disturbance begins to approach dry saharan air in the central tropical Atlantic...and the less favorable upper vorticity currently concentrated southof the Azores will dive southwestward toward the central tropical Atlantic as well. Therefore development of this disturbance is not expected.

The following statement concerns area of interest #2 marked over western Africa in the atmospheric features chart below. Computer models (particularly the GFS) suggest that a vigorous tropical wave will emerge from western Africa and into the eastern tropical Atlantic in 120 hours (5 days)...with the possibility of development into a tropical cyclone due to favorable atmospheric conditions supplied by the upper ridge currently in the eastern tropcial Atlantic and also as the disturbance to its west (area of interest #1) helps moisten out some of the unfavorable dry Saharan air in the central tropical Atlantic.

...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).

2016 Atlantic Hurricane Season Birdseye Discussion #67

By: NCHurricane2009, 11:43 AM GMT on July 22, 2016

...FRIDAY JULY 22 2016 7:45 AM EDT...
The following statement concerns area of interest #1 marked over the eastern tropical Atlantic in the atmospheric features chart below. A rather large area of showers and thunderstorms continues as a tropical wave in the region interacts with upper divergence on the south side of an upper ridge expanding in the eastern tropical Atlantic...and a 1013 mb surface low has formed in this area centered just south of the Republic of Cabo Verde. Warm air advection ahead of the 1002 mb frontal cyclone over the north Atlantic has developed an upper ridge over the northeast Atlantic...and in turn an upper vortex is beginning to develop between the northeast Atlantic and eastern tropical Atlantic upper ridges. Therefore as this tropical disturbance continues westward...it will later encounter this less favorable upper vortex as the upper vortex dives southward toward the central tropical Atlantic. Currently there are no signs of organization and computer models do not forecast development.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0127Z-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 #66

By: NCHurricane2009, 5:47 AM GMT on July 21, 2016

...THURSDAY JULY 21 2016 1:48 AM EDT...
The following statement concerns area of interest #1 marked over the eastern tropical Atlantic and western Africa in the atmospheric features chart below. A rather large area of showers and thunderstorms continues as a tropical wave in the region interacts with upper divergence on the south side of an upper ridge expanding in the eastern tropical Atlantic. Warm air advection ahead of the 1000 mb frontal cyclone over eastern Canada has developed an upper ridge over the north Atlantic...and in turn an upper vortex is beginning to develop between the north Atlantic and eastern tropical Atlantic upper ridges. This area of disturbed weather has 120 hours to develop underneath the more favorable eastern tropical Atlantic upper ridge...after which time the upper vortex could dive south and makes atmospheric conditions less favorable. Currently there are no signs of organization and computer models do not forecast development.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0143Z-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 #65

By: NCHurricane2009, 9:44 PM GMT on July 20, 2016

**(Statement as of 5:44 PM EDT) It was intended that this blog be posted at 1:15 AM EDT this morning. However a glitch that occurred to my Wunderground account prevented me from releasing this post on time**

...WEDNESDAY JULY 20 2016 1:15 AM EDT...
The following statement concerns area of interest #1 marked over Central America in the atmospheric features chart below. The tropical disturbance that developed over the southern Caribbean Sea has moved into Central America...and if the current west-northwest trajectory continues the disturbance will remain over land over Central America and southeastern Mexico which will prevent tropical development.

The following statement concerns area of interest #2 marked over the eastern tropical Atlantic and western Africa in the atmospheric features chart below. A rather large area of showers and thunderstorms has developed in the last 24 hours perhaps as a tropical wave or two in the region interacts with upper divergence on the south side of an upper ridge expanding in the eastern tropical Atlantic. Warm air advection ahead of the 997 mb frontal cyclone over eastern Canada will develop an upper ridge over the north Atlantic...with an upper vortex forming between the north Atlantic and eastern tropical Atlantic upper ridges. This area of disturbed weather only has 120 hours to develop underneath the more favorable eastern tropical Atlantic upper ridge before the upper vortex dives south and makes atmospheric conditions less favorable. Currently there are no signs of organization and computer models do not forecast development.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0129Z-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 #64

By: NCHurricane2009, 4:44 AM GMT on July 19, 2016

...TUESDAY JULY 19 2016 12:45 AM EDT...
Resuming blog updates due to an area of disturbed weather that has developed over the southern Caribbean Sea this past afternoon...

The following statement concerns area of interest #1 marked over the southern Caribbean Sea and parts of Central America. A significant increase in showers and thunderstorms in the area...featuring cyclonic turning...has developed as a surface tropical wave interacts with the upper-level outflow of an upper ridge over the area. At one point over the last few days the NAVGEM computer model predicted this area would develop and track west-northwest into the Bay of Campeche in the southwestern Gulf of Mexico and develop there. However all latest model runs do not show this tropical wave developing on the Atlantic side. Instead this disturbance is likely to track over Central America and southeastern Mexico and not develop due to land interaction...or alternatively develop over the eastern Pacific.

...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).

2016 Atlantic Hurricane Season Birdseye Discussion #63B (Special Update)

By: NCHurricane2009, 5:44 AM GMT on July 14, 2016

...THURSDAY JULY 14 2016 1:45 AM EDT...
A vigorous tropical wave which has recently emerged from the west coast of Africa is producing an organized tropical surface low pressure spin to the south-souheast of the Republic of Cabo Verde in the eastern tropical Atlantic...centered at 10N-20W. Upper-level winds will be generally favorable for development as the tropical wave continues westward as an upper ridge expands from the eastern Atlantic. However like recent tropical waves...computer models currently do not forecast development and unfavorable dry saharan air lies ahead in its path. However should this tropical wave develop further before reaching the dry air...or develop a moisture field and resist dry air...I will consider resuming daily updates on this blog.

2016 Atlantic Hurricane Season Birdseye Discussion #63A (Special Update)

By: NCHurricane2009, 6:12 AM GMT on July 12, 2016

...TUESDAY JULY 12 2016 2:13 AM EDT...
The Atlantic tropics are expected to remain quiet for the next several days. Therefore I have ceased doing daily updates on this blog until the threat of tropical cyclone activity returns to the Atlantic basin.

2016 Atlantic Hurricane Season Birdseye Discussion #63

By: NCHurricane2009, 5:43 AM GMT on July 11, 2016

...MONDAY JULY 11 2016 1:45 AM EDT...
The following statement concerns area of interest #1 marked in the eastern Caribbean Sea in the atmospheric features chart below. A vigorous tropical wave in the area has lost thunderstorm activity. The inverted upper trough to its west has further evolved into a cut-off upper vortex in the central Caribbean (marked by blue L the left of the area of interest). This upper vortex is likely to suppress this tropical wave further as it continues across the Caribbean...therefore this is my final statement on this blog for this area of interest.

The following statement concerns area of interest #2 marked in the north-central Atlantic in the above atmoshperic features chart below. The 1007 mb surface frontal low that was in the northwest Atlantic offshore of southeastern Canada has accelerated northeastward into cooler north-central Atlantic waters...which has resulted in a significant reduction in its thunderstorm activity before it could further acquire tropical characteristics. This surface frontal low will become absorbed in the next 48 hours by what is currently the much larger 1004 mb frontal cyclone just offshore of Nova Scotia following behind. This is my final statement on this area of interest on this blog.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0132Z-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 #62

By: NCHurricane2009, 4:42 AM GMT on July 10, 2016

...SUNDAY JULY 10 2016 12:30 AM EDT...
A short-lived tropical cyclone may develop in the northwestern Atlantic to the southeast of Canada in the next 24 hours...see statement about area of interest #2 below for additional details. Should this area of interest become upgraded to a tropical cyclone during this time...I will not be able to issue a special update as I will be on a road trip. Therefore stay tuned to www.nhc.noaa.gov in regards to area of interest #2.

The following statement concerns area of interest #1 marked in the central tropical Atlantic and approaching the Lesser Antilles and eastern Caribbean Sea in the atmospheric features chart below. A vigorous and somewhat organized tropical wave in the area has re-gained some thunderstorm activity in the last 24 hours while it continues westward. However an inverted upper trough fracture (marked by blue-dashed line to the left of the area of interest) has moved into the Caribbean in advance of the tropical wave...and it is this upper-level feature that is likely to suppress this tropical wave as it continues across the Caribbean. Therefore chances are unlikely that this tropical wave develops and computer models continue to show no development from this wave.

The following statement concerns area of interest #2 marked in the northwestern Atlantic and offshore of southeastern Canada in the above atmoshperic features chart below. A 1007 mb surface low has developed along a lengthy surface front draped across the region...supported by divergent upper westerly flow on the northwest side of an upper anticyclone. Strong and organized thunderstorm activity has rapidly developed with this feature as it is still near 26 deg C water temperatures. Because the surface low is tracking rapidly east-northeastward...it is somewhat matching the upper westerly wind speed and thus limiting the effects of vertical shear...allowing the strong thunderstorms to be close to the surface center and thus taking on the apperance of a tropical cyclone this evening. This trend is likely to be short-lived such that the National Hurricane Center is unlikely to declare a tropical cyclone and thus I have not upgraded it to a special feature on this blog. This is because this system will be accelerating northeastward quickly into cooler waters...and by 72 hours will be over rather cool waters between Europe and Canada while becoming absorbed by what is currently the much larger 1007 mb frontal cyclone over the northeastern US following behind.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1930Z-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 #61

By: NCHurricane2009, 5:10 AM GMT on July 09, 2016

...SATURDAY JULY 9 2016 1:11 AM EDT...
The following statement concerns area of interest #1 marked in the central tropical Atlantic in the atmospheric features chart below. Although a vigorous tropical wave in the area remains organized while continuing westward...its thunderstorm activity has weakened perhaps while ingesting some of the dry Saharan air in this region. Moreover...the southwest part of an unfavorable inverted upper trough to the northwest will fracture and move into the Caribbean Sea at the same time this tropical wave moves into the Caribbean. Therefore chances are unlikely that this tropical wave develops and computer models continue to show no development from this wave.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0134Z-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 #60

By: NCHurricane2009, 3:06 AM GMT on July 08, 2016

...THURSDAY JULY 7 2016 11:07 PM EDT...
The following statement concerns area of interest #1 marked west-southwest of the Republic of Cabo Verde and moving into the central tropical Atlantic in the atmospheric features chart below. A vigorous surface tropical wave in the area has seen an increase in the intensity and organization of showers and thunderstorms while its poleward upper outflow is enhanced by a cut-off upper vortex to the northwest. However as this tropical wave moves toward the Lesser Antilles and into the Caribbean Sea in the next 96 hours (4 days)...it will potentially encounter less favorable dry Saharan air in the central tropical Atlantic...and the southwest part of the aforementioned cut-off upper vortex will leave behind an unfavorable inverted upper trough that also moves into the Caribbean. Therefore chances are unlikely that this tropical wave develops and computer models continue to show no development from this wave.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1930Z-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 #59

By: NCHurricane2009, 3:33 AM GMT on July 07, 2016

...WEDNESDAY JULY 6 2016 11:34 PM EDT...
The following statement concerns area of interest #1 marked southwest of the Republic of Cabo Verde in the eastern tropical Atlantic in the atmospheric features chart below. A vigorous tropical wave in the area has once again become less organized and less active. Therefore this is my final statement on this tropical wave on this blog unless it re-organizes or becomes active 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 box 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, blue Hs are locations of upper ridges.

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, Hs indicate surface highs.

...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 #58

By: NCHurricane2009, 3:27 AM GMT on July 06, 2016

...TUESDAY JULY 5 2016 11:27 PM EDT...
The following statement concerns area of interest #1 marked south of the Republic of Cabo Verde in the eastern tropical Atlantic in the atmospheric features chart below. A vigorous tropical wave in the area initially lost activity and became less organized...but then recently has shown signs of re-organizing to the south of the Republic of Cabo Verde. The cut-off upper vortex to the northwest has weakened into an inverted upper trough while moving westward and away...and this upper air pattern is expected to continue which will keep atmospheric conditions favorable for development as the tropical wave continues westward. However it remains to be seen if dry Saharan air currently in the central tropical Atlantic prevents this tropical wave from development. Currently no computer models show development of this tropical wave.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1924Z-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 box 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, blue Hs are locations of upper ridges.

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, Hs indicate surface highs.

...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 #57

By: NCHurricane2009, 3:29 AM GMT on July 05, 2016

...MONDAY JULY 4 2016 11:30 PM EDT...
The following statement concerns area of interest #1 marked over the the west coast of Africa and eastern tropical Atlantic in the atmospheric features chart below. A vigorous and organized tropical wave is emerging from the west coast of Africa. Although a nearby cut-off upper vortex has developed to the northwest of the Republic of Cabo Verde...this upper vortex is expected to retrograde westward and away which will keep the upper winds over the tropical wave favorable as it moves into and across the tropical Atlantic...and therefore will watch this tropical wave. It remains to be seen if dry Saharan air currently in the central tropical Atlantic prevents this tropical wave from development.

...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 box 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, blue Hs are locations of upper ridges.

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, Hs indicate surface highs.

...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 #56

By: NCHurricane2009, 7:31 AM GMT on July 04, 2016

...MONDAY JULY 4 2016 3:35 AM EDT...
The following statement concerns area of interest #1 marked over the central tropical Atlantic in the atmospheric features chart below. Showers and thunderstorms associated with a tropical wave around 52W longitude have become less organized and have considerably weakened. Moreover as the tropical wave continues westward...this disturbance will encounter less favorable westerly vertical shear induced by the cut-off upper vortex currently northeast of the Lesser Antilles. Therefore tropical development here is not expected.

...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 box 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, blue Hs are locations of upper ridges.

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, Hs indicate surface highs.

...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 #55

By: NCHurricane2009, 6:00 AM GMT on July 03, 2016

...SUNDAY JULY 3 2016 2:00 AM EDT...
The following statement concerns area of interest #1 marked over the central tropical Atlantic in the atmospheric features chart below. Showers and thunderstorms around 45W longitude have continued to become better organized while still ventilated by poleward outflow of an upper ridge expanding from the eastern tropical Atlantic...and while becoming focused around a surface low pressure center along a surface tropical wave. Although this favorable upper ridge is expected to expand westward as this disturbance moves westward...it is possible that as it approaches the Lesser Antilles in the next 48 hours this disturbance will encounter less favorable westerly vertical shear induced by the cut-off upper vortex that has just formed northeast of the Lesser Antilles...which could ultimately prevent development of this disturbance.

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 0000Z and 0135Z-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 box 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, blue Hs are locations of upper ridges.

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, Hs indicate surface highs.

...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 #54

By: NCHurricane2009, 6:59 AM GMT on July 02, 2016

...SATURDAY JULY 2 2016 3:00 AM EDT...
The following statement concerns area of interest #1 marked in the northwestern Gulf of Mexico in the atmospheric features chart below. The surface low south of Louisiana has diminished into a surface trough while moving toward Texas...development here is not expected.

The following statement concerns area of interest #2 marked over the central tropical Atlantic in the atmospheric features chart below. Showers and thunderstorms around 40W longitude have increased and become better organized over the past couple of days while tropical waves passing through the region have interacted with poleward outflow supplied by an upper ridge expanding over the eastern half of the tropical Atlantic. Although this favorable upper ridge is expected to expand westward as this disturbance moves westward...it is possible that as it approaches the Lesser Antilles in the next 72 hours...this disturbance will encounter less favorable westerly vertical shear induced by a cut-off upper vortex that is expected to form north of the Lesser Antilles...which could ultimately prevent development of this disturbance. This cut-off is expected to form from a fracture of the currently large upper vortex located in the middle of the Atlantic (marked by blue L in the middle of the atmospheric featuers chart below).

...ATMOSPHERIC FEATURES BIRDSEYE CHART...

This chart is generated based on surface analysis from the National Hurricane Center TAFB at 1800Z and 1919Z-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 box 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, blue Hs are locations of upper ridges.

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, Hs indicate surface highs.

...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 #53

By: NCHurricane2009, 3:49 AM GMT on July 01, 2016

...THURSDAY JUNE 30 2016 11:50 PM EDT...
The following statement concerns area of interest #1 marked in the northern Gulf of Mexico in the atmospheric features chart below. A 1013 mb surface low remains generally stationary to the south of Louisiana while a shortwave upper trough over eastern Texas has moved closer and imparted less favorable westerly vertical shear. However this shortwave is forecast to evolve into a cut-off upper vortex that moves away into south Texas...allowing for upper winds to become a bit more favorable again. As the pair of upper troughs and surface frontal cyclones currently over eastern North America move eastward and away...surface ridging will solidify to the north of the surface low south of Louisiana...which will push the surface low westward toward Texas in the next 48 hours. Will continue to watch this surface low for development but so far there are no signs of this occuring.

It remains quiet elsewhere in the Atlantic tropics.

...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 box 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, blue Hs are locations of upper ridges.

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, Hs indicate surface highs.

...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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