Which Hurricane Forecast Model Should You Trust?

By: Dr. Jeff Masters , 1:05 PM GMT on August 07, 2013

The National Hurricane Center (NHC) set a new record in 2012 for accuracy of their 1, 2, 3, and 4-day Atlantic tropical cyclone track forecasts, but had almost no skill making intensity forecasts, according to the 2012 National Hurricane Center Forecast Verification Report, issued in March 2013. The new records for track accuracy were set despite the fact that the season’s storms were harder than average to forecast. The average error in a 1-day forecast was 46 miles, and was 79 miles for 2 days, 116 miles for 3 days, 164 miles for 4 days, and 224 miles for 5 days. The official track forecast had a westward bias of 10 - 17 miles for 1 - 3 day forecasts (i.e., the official forecast tended to fall to the west of the verifying position), and was 38 and 75 miles too far to the northeast for the 4- and 5-day forecasts, respectively.


Figure 1. Verification of official NHC hurricane track forecasts for the Atlantic, 1990 - 2012. Over the past 15 - 20 years, 1 - 3 day track forecast errors have been reduced by about 60%. Track forecast error reductions of about 50% have occurred over the past ten years for 4- and 5-day forecasts. Image credit: 2012 National Hurricane Center Forecast Verification Report.

NHC Intensity Forecasts: Little Improvement Since 1990
Official NHC intensity forecasts did better than usual in 2012, and had errors lower than the 5-year average error for 1, 2, 3, 4, and 5-day forecasts. However, 2012's storms were easier to predict than usual, due to due to a lack of rapidly intensifying hurricanes. These rapid intensifiers are typically the source of the largest forecast errors. The skill of official NHC 24-hour intensity forecasts made in 2012 for the Atlantic basin were only about 15% better than a "no-skill" forecast; 2, 3, 4, and 5-day intensity forecasts had no skill.


Figure 2. Verification of official NHC hurricane intensity forecasts for the Atlantic, 1990 - 2012. Intensity forecasts have shown little to no improvement since 1990. Image credit: 2012 National Hurricane Center Forecast Verification Report.

Which Track Model Should You Trust?
As usual, in 2012 the official NHC forecast for Atlantic storms was almost as good as or better than any individual computer models--though NOAA's GFS model did slightly better than the NHC official forecast at 12, 24, and 48-hour periods, and the European model forecast was slightly better at 12-hour forecasts. Despite all the attention given to how the European Center (ECMWF) model outperformed the GFS model for Hurricane Sandy's track at long ranges, the GFS model actually outperformed the European model in 2012 when summing up all track forecasts made for all Atlantic named storms. This occurred, in part, because the European model made a few disastrously bad forecasts for Tropical Storm Debby when it was in the Gulf of Mexico and steering currents were weak. For several runs, the model predicted a Texas landfall, but Debby ended up moving east-northeast to make a Northwest Florida landfall, like the GFS model had predicted. However, the best-performing model averaged over the past three years has been the European Center model, with the GFS model a close second. Wunderground provides a web page with computer model forecasts for many of the best-performing track models used to predict hurricane tracks. The European Center does not permit public display of tropical storm positions from their hurricane tracking module of their model, so we are unable to put ECMWF forecasts on this page. Here are some of the better models NHC regularly looks at:

ECMWF: The European Center's global forecast model
GFS: NOAA's global forecast model
NOGAPS: The Navy's global forecast model (now defunct, replaced by the NAVGEM model in 2013)
UKMET: The United Kingdom Met Office's global forecast model
GFDL: The Geophysical Fluid Dynamics Laboratory's hurricane model, initialized using GFS data
HWRF: The intended successor for the the GFDL hurricane model, also initialized using GFS data
CMC: The Canadian GEM model
BAMM: The very old Beta and Advection Model (Medium layer), which is still useful at longer ranges

If one averages together the track forecasts from the first six of these models, the NHC official forecast will rarely depart much from it. As seen in Figure 3, the HWRF and UKMET were well behind the ECMWF and GFS in forecast accuracy in 2012, but were still respectable. The simple BAMM model did well at 3, 4, and 5-day forecasts. The GFDL and CMC models did quite poorly compared to the ECMWF, GFS, UKMET, and HWRF. The Navy's NOGAPS model also did poorly in 2012, and has been retired. Its replacement for 2013 is called the NAVGEM model.


Figure 3. Skill of computer model forecasts of Atlantic named storms in 2012, compared to a "no skill" model called "CLIPER5" that uses just climatology and persistence to make a hurricane track forecast (persistence means that a storm will tend to keep going in the direction it's current going.) OFCL=Official NHC forecast; GFS=Global Forecast System model; GFDL=Geophysical Fluid Dynamic Laboratory model; HWRF=Hurricane Weather Research Forecasting model; UKMET=United Kingdom Met Office model; ECMWF=European Center for Medium Range Weather Forecasting model; TVCA=one of the consensus models that lends together several of the above models; CMC=Canadian Meteorological Center (GEM) model; BAMM=Beta Advection Model (Medium depth.) Image credit: National Hurricane Center 2012 verification report.

Which Intensity Model Should You Trust?
Don't trust any of them. NHC has two main statistical intensity models, LGEM and DSHP (the SHIPS model with inland decay of a storm factored in.) In addition, four dynamical models that are also use to track hurricanes--the GFS, ECMWF, HWRF, and GFDL models--all offer intensity forecasts. With the exception of the GFS model, which had a skill just 5% better than a "no-skill" intensity forecast for predictions going out 36 hours, all of these models had no skill in their intensity forecasts during 2012. The ECMWF and HWRF models were the worst models for intensity forecasts of 3, 4, and 5 days, with a skill of 20% - 60% lower than a "no-skill" forecast. The LGEM model, which was a decent intensity model in 2011, tanked badly in 2012 and had near-zero skill. The only model that was any good in 2012 was the IVCN "consensus" model, which averages together the intensity forecasts of two or more of the intensity models such as LGEM, GFDL, HWRF, and DSHP.

Some Promising Models From the Hurricane Forecast Improvement Project (HFIP)
Last year was the fourth year of a ten-year project, called the Hurricane Forecast Improvement Project (HFIP), aimed at reducing hurricane track and intensity errors by 50%. The new experimental models from HFIP generally performed poorly in 2012. However, the new FIM9 15-km global model was competitive with the ECMWF and GFS models for track, and the new CIRA Statistical Intensity Consensus (SPC3) model for intensity performed better than many of the traditional intensity models.

For those interested in learning more about the hurricane forecast models, NOAA has a 1-hour training video (updated for 2011.) Additional information about the guidance models used at the NHC can be found at NHC and the NOAA/HRD Hurricane FAQ.

Sources of Model Data
You can view 7-day ECMWF and 16-day GFS forecasts on wunderground's wundermap with the model layer turned on.
Longer ten-day ECMWF forecasts are available from the ECMWF web site.
FSU's experimental hurricane forecast page (CMC, ECMWF, GFDL, GFS, HWRF, and NAVGEM models)
NOAA's HFIP model comparison page (GFS, ECMWF, FIM, FIM9, UKMET, and CMC models.)
Experimental HFIP models

Quiet in the Atlantic
There are no tropical cyclone threat areas in the Atlantic to discuss today, and none of the reliable models for tropical cyclone formation is predicting development during the coming seven days. I plan on having a detailed update on Friday to discuss the latest long-range forecasts for the coming peak part of hurricane season.

Jeff Masters


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

Reader Comments

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1086 - 1036

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40Blog Index

1086. flcanes
Quoting 1081. Waltanater:
My long range model shows a major hitting FL the week of Nov. 4th...but that is a long way away.

??????????
What long range model?
Member Since: Posts: Comments:
Look at the vorticity with this wave about to exit Africa. Yikes!

Member Since: Posts: Comments:
Also looks like we may see developement off this front east of Bermuda as well. Starting to get the feel that we maybe tracking 4 to 5 systems at once over the next 2 weeks. Things are starting to pop!

Look about 300 miles east of Bermuda and you can start to see another spin organizing.


Member Since: Posts: Comments:
1083. SLU
GEFS starting to verify with lowering pressures

Member Since: Posts: Comments:
Quoting 1050. CenterOfGravity:
@ Mikanight,,

Nice post and well done but I respectfully disagree with your evaluation.

I Do not want to stray off topic but imo this is relevant to the conversation.

I do not see any progress in travel.Still using fossil fuels,,cars.

Have no space program to speak of

Yes we have cell phones and computers but little progress in many other areas for the last 40+ years,,superficial improvements in a few areas of knowledge but nothing of significance.

We have had not had any major breakthroughs in many decades,,,except for Cern" possibly with the Boson particle research,,that remains to be seen.This possibly might confirm Tiplers's Thoughts.It remains to be seen.

I believe going back to the 1890"s,,,the world advancements were like a adolescent boy,,,he get his growth spurt and goes from 5-6" to 6-1 in 2 years but then his growth is slowed very much after as we have been in the last several decades in advancements.


This just my thoughts and my opinion,,thanks for posting back,,,tc


A friend of mine once said something similar, asking what major breakthroughs have occurred since the atomic bomb. They've improved things but nothing really "new". I tend towards Ray Kurzweil's thinking in that humans are on a march towards a quantem leap in intelligence by incorporating machines into themselves in order to keep up with computers. Also, things are happening much faster than we realize. The 10 year genome project was only 1% complete after 3 years and all said they'd never make their goal. But progress doubled every year and, well, you know the rest.
Uh oh, gotta get the GM pics ready...see ya in 39 minutes!
Member Since: Posts: Comments:
My long range model shows a major hitting FL the week of Nov. 4th...but that is a long way away.
Member Since: Posts: Comments:
1078. beell
Quoting 1076. FOREX:


guess not.


Climatologically speaking, no.
Member Since: December 31, 1969 Posts: Comments:
1076. FOREX
Quoting 1056. FOREX:


Would the blob coming off of land into water right now in South America, just West of the AOI be an area for possible development, climatologically?


guess not.
Member Since: Posts: Comments:
I suspect it's this little guy spinning in the Southern Caribbean that the GFS likes for potential developement early next week. Once this wave moves into the NW Caribbean early next week then conditions will be favorable for developement.

Member Since: Posts: Comments:
2005 was an unusual year (and with several storms in June and July) but here is what a typical late-August to September Cape Verde wave storm cluster looks like (from the NOAA 2005 Season Summary):

[KATRINA] THIS HORRIFIC TROPICAL CYCLONE FORMED FROM A TROPICAL WAVE...BECOMING A DEPRESSION ABOUT 175 MILES SOUTHEAST OF NASSAU IN THE BAHAMAS ON 23 AUGUST.

TROPICAL STORM LEE DEVELOPED FROM A TROPICAL WAVE OVER THE CENTRAL TROPICAL ATLANTIC...FIRST BECOMING A DEPRESSION ON 28 AUGUST ABOUT 925 MILES EAST OF THE LESSER ANTILLES

MARIA DEVELOPED FROM A VIGOROUS TROPICAL WAVE THAT CROSSED THE WEST COAST OF AFRICA ON 27 AUGUST.

HURRICANE NATE FORMED FROM A TROPICAL WAVE THAT EXITED THE COAST OF AFRICA ON 30 AUGUST.

ERRATIC HURRICANE OPHELIA FORMED FROM AN AREA OF DISTURBED WEATHER ALONG THE WESTERN END OF AN OLD FRONTAL SYSTEM. THE CYCLONE BEGAN TO ORGANIZE ON 4 SEPTEMBER OVER THE CENTRAL AND NORTHWESTERN BAHAMAS...AND A TROPICAL DEPRESSION FORMED ON 6 SEPTEMBER NEAR GRAND BAHAMA ISLAND. THE DEPRESSION MOVED ERRATICALLY NORTH-NORTHWESTWARD AND BECAME TROPICAL STORM OPHELIA ON 7 SEPTEMBER ABOUT 115 MILES EAST-SOUTHEAST OF CAPE CANAVERAL FLORIDA.

PHILIPPE FORMED FROM A TROPICAL WAVE...BECOMING A DEPRESSION ON 17 SEPTEMBER ABOUT 305 MILES EAST OF BARBADOS.

RITA BECAME A DEPRESSION JUST EAST OF THE TURKS AND CAICOS ISLANDS LATE ON 17 SEPTEMBERR. IT MOVED WESTWARD AND BECAME A TROPICAL STORM THE FOLLOWING AFTERNOON.

STAN DEVELOPED FROM A TROPICAL WAVE THAT GENERATED A PERSISTENT AREA OF DISTURBED WEATHER OVER THE WESTERN CARIBBEAN SEA IN LATE SEPTEMBER. A TROPICAL DEPRESSION EVENTUALLY FORMED ON 1 OCTOBER ABOUT 110 MILES SOUTHEAST OF COZUMEL MEXICO.



We are not there yet; Patience is the word and give it three weeks.
Member Since: Posts: Comments:
Good morning everyone! Well a little bit more rain last night, forgot to check the gauge but I'm guessing about .5". Zero days and counting without rain in my part of NW Florida!
Member Since: Posts: Comments:
FL is in for a serious amount of rain next week whether this system developes or not a big rain event of 5" to 10" next week looks solid.

Member Since: Posts: Comments:
Aislin, you went all out this morning. I may need to try the grill cheese w bacon. The others sound like ones that should be morning standards!

Mik, that scale seems wrong for two reasons. Tech improves on a log scale so in 100 years we should advance more, but there is also the counter current to do more with less energy. For example, if we harness a passing CME to move 10x faster than existing spacecraft, did we use 0 energy like a sailing ship or a massive amount like a nuclear sub? If we grow a house out of CO2, sunlight, and water instead of mining concrete, burning it in a massively wasteful kiln, hauling it to the home site, and mixing it up with water... is that more or less advanced/energy intensive? We may actually move backward on the scale of energy usage.
Member Since: Posts: Comments:
Looks like the GFS is beginning to develope a system off the SW coast of FL.


Member Since: Posts: Comments:
Quoting 1065. AtHomeInTX:
Morning all. GFS ensembles starting to show Atlantic storms making it across. Of course it loses the gulf storm as it nears TX. This run anyway. :)



Probably evaporates when it approaches the Texas coast!
Member Since: Posts: Comments:
Morning all. GFS ensembles starting to show Atlantic storms making it across. Of course it loses the gulf storm as it nears TX. This run anyway. :)

Member Since: Posts: Comments:


2nd low is far south.
Member Since: December 31, 1969 Posts: Comments:
Good morning, afternoon and evening, everyone. A 100% humid 75 degrees with 75 degree dew point and feels like 81 already. High expected of 98 and no rain in sight. Even with all my watering my garden is beginning to suffer.

Breakfast's on the sideboard: fruity granola and yogurt parfait, baked eggs and spinach, broccoli & cheddar omelet, bacon and grill cheese sandwich
baked egg in an avocado with and without crumbled bacon, egg white or full egg cheese wrap,
andouille sausage and shrimp over cheesey grits,cheese danishes, yogurt, fresh fruit and orange, apple or pineapple juice. Enjoy!

Member Since: Posts: Comments:
Hello folks!

Member Since: Posts: Comments:
Quoting 1031. Civicane49:
Southeastern Caribbean disturbance remains at 10%.

1. A WEAK LOW PRESSURE SYSTEM IS PRODUCING A SMALL AREA OF CLOUDINESS
AND SHOWERS OVER THE SOUTHEASTERN CARIBBEAN SEA. ENVIRONMENTAL
CONDITIONS DO NOT APPEAR CONDUCIVE FOR DEVELOPMENT AS THE LOW MOVES
WESTWARD AT 10 TO 15 MPH DURING THE NEXT SEVERAL DAYS. THIS SYSTEM
HAS A LOW CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS...AND A LOW CHANCE...10 PERCENT...OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS.
Why do they state the percentage is the same for the next 2 days and then repeat the same percentage for the next 5 days!?...in 3-4 days it will be over land..assuming it doesn't change course...doesn't make sense at all. I don't think they are giving much to their new 5 day expectency.
Member Since: Posts: Comments:
Quoting 1031. Civicane49:
Southeastern Caribbean disturbance remains at 10%.

1. A WEAK LOW PRESSURE SYSTEM IS PRODUCING A SMALL AREA OF CLOUDINESS
AND SHOWERS OVER THE SOUTHEASTERN CARIBBEAN SEA. ENVIRONMENTAL
CONDITIONS DO NOT APPEAR CONDUCIVE FOR DEVELOPMENT AS THE LOW MOVES
WESTWARD AT 10 TO 15 MPH DURING THE NEXT SEVERAL DAYS. THIS SYSTEM
HAS A LOW CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS...AND A LOW CHANCE...10 PERCENT...OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS.
Really?!...It's a cloud! Barely worth mentioning!
Member Since: Posts: Comments:
Quoting Tropicsweatherpr:
Good morning to all.

Is eerie quiet out there on August 8 in the Atlantic with nothing immiment from the models and not even a invest to follow. (Except that small area in ABC islands) Things are falling into place as climo suggests but still the reliable models continue quiet. The calm before the wild ride begins it seems.


Models have been wrong before so I am not surprised they are not showing anything.
Member Since: Posts: Comments:
1056. FOREX
Quoting 1055. Tropicsweatherpr:
Good morning to all.

Is eerie quiet out there on August 8 in the Atlantic with nothing immiment from the models and not even a invest to follow. (Except that small area in ABC islands) Things are falling into place as climo suggests but still the reliable models continue quiet. The calm before the wild ride begins it seems.


Would the blob coming off of land into water right now in South America, just West of the AOI be an area for possible development, climatologically?
Member Since: Posts: Comments:
Good morning to all.

Is eerie quiet out there on August 8 in the Atlantic with nothing immiment from the models and not even a invest to follow. (Except that small area in ABC islands) Things are falling into place as climo suggests but still the reliable models continue quiet. The calm before the wild ride begins it seems.
Member Since: December 31, 1969 Posts: Comments:
1054. beell
Quoting 1043. CaicosRetiredSailor:



ABC blob


(The ABC islands are Aruba, Bonaire and Curacao.)


Is that "Actual size", CRS?
Member Since: December 31, 1969 Posts: Comments:
Good morning
Member Since: Posts: Comments:
1052. LargoFl
Good Morning Folks..Blogs COFFEE is perked..enjoy..
Member Since: Posts: Comments:
1051. LargoFl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
319 AM EDT THU AUG 8 2013

.SHORT TERM (TODAY - SATURDAY)...
SURFACE AND UPPER LEVEL RIDGING WILL REMAIN IN PLACE TO THE NORTH
OF THE FORECAST AREA TODAY AS AN UPPER LEVEL LOW MOVES WEST
THROUGH THE SOUTHERN BAHAMAS TOWARDS THE FLORIDA STRAITS. SIMILAR
TO YESTERDAY AMPLE MOISTURE AND DAYTIME HEATING WILL AGAIN SUPPORT
SCATTERED DIURNAL SEA BREEZE DRIVEN SHOWERS AND STORMS DURING THE
AFTERNOON AND EARLY EVENING HOURS. WITH A SLIGHTLY STRONGER EAST
TO SOUTHEAST FLOW TODAY THE WEST COAST SEA BREEZE BOUNDARY WILL
LIKELY GET PINNED CLOSE TO THE COAST DURING THE AFTERNOON AND WILL
INTERACT WITH THE WESTWARD MOVING EAST COAST BOUNDARY DURING THE
MID AND LATE AFTERNOON HOURS. THE MAV/MET POPS AGAIN LOOK TOO
LOW...AND HAVE GONE ABOVE WITH 40 PERCENT POPS RIGHT ALONG THE
COAST...AND 30 PERCENT ACROSS THE REMAINDER OF THE FORECAST AREA.

TONIGHT AND FRIDAY THE AFOREMENTIONED UPPER LEVEL LOW WILL MOVE
WEST THROUGH THE FLORIDA STRAITS AND INTO THE SOUTHEAST GULF OF
MEXICO AS UPPER AND SURFACE RIDGING REMAINS ANCHORED TO THE NORTH.
MODELS SHOW SOME DRIER MID LEVEL AIR AND SUBSIDENCE MOVING INTO
THE FORECAST AREA TONIGHT AHEAD OF THE UPPER LEVEL LOW (PW`S
DROPPING TO AROUND 1.5 INCHES) WHICH SHOULD KEEP THINGS DRY
OVERNIGHT THROUGH EARLY FRIDAY MORNING ONCE THE CONVECTION WINDS
DOWN AFTER SUNSET. THEREAFTER DEEPER MOISTURE (PW`S CLIMBING BACK
INTO THE 1.8 TO 1.9 INCH RANGE) RETURNS TO THE REGION FRIDAY
AFTERNOON. THIS DEEPER MOISTURE COMBINED WITH STEEPENING LAPSE
RATES FROM COLDER MID LEVEL TEMPERATURES ASSOCIATED WITH THE UPPER
LEVEL LOW PASSING BY TO THE SOUTHWEST SHOULD SUPPORT SCATTERED
SHOWERS AND STORMS (POPS 30 TO 40 PERCENT RANGE INLAND TO THE
COAST) DURING THE AFTERNOON AND EARLY EVENING HOURS...WITH A FEW
STRONG STORMS POSSIBLE ACROSS SOUTHERN ZONES WITH STRONG GUSTY
WINDS AND SMALL HAIL THE MAIN HAZARDS.

Member Since: Posts: Comments:
@ Mikanight,,

Nice post and well done but I respectfully disagree with your evaluation.

I Do not want to stray off topic but imo this is relevant to the conversation.

I do not see any progress in travel.Still using fossil fuels,,cars.

Have no space program to speak of

Yes we have cell phones and computers but little progress in many other areas for the last 40+ years,,superficial improvements in a few areas of knowledge but nothing of significance.

We have had not had any major breakthroughs in many decades,,,except for Cern" possibly with the Boson particle research,,that remains to be seen.This possibly might confirm Tiplers's Thoughts.It remains to be seen.

I believe going back to the 1890"s,,,the world advancements were like a adolescent boy,,,he get his growth spurt and goes from 5-6" to 6-1 in 2 years but then his growth is slowed very much after as we have been in the last several decades in advancements.


This just my thoughts and my opinion,,thanks for posting back,,,tc
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Baby steps...

Current status of human civilization

Further information: World energy resources and consumption

Michio Kaku suggested that humans may attain Type I status in about 100–200 years, Type II status in a few thousand years, and Type III status in about 100,000 to a million years.
Carl Sagan suggested defining intermediate values (not considered in Kardashev's original scale) by interpolating and extrapolating the values given above for types I (1016 W), II (1026 W) and III (1036 W), which would produce the formula



where value K is a civilization's Kardashev rating and P is the power it uses, in watts. Using this extrapolation, a "Type 0" civilization, though not defined by Kardashev, would control about 1 MW of power, and humanity's civilization type (in 1973) was about 0.7 (apparently using 10 terawatt (TW) as the value for 1970s humanity).
In 2008, total world energy consumption was 474 exajoules (474×1018 J=132,000 TWh), equivalent to an average power consumption of 15 TW (or 0.72 on Sagan's Kardashev scale).

LINK
Member Since: Posts: Comments:
"Which Intensity Model Should You Trust?
Don't trust any of them."

Kardashev Type #1 Civilization We are ?

At this rate we are not going to reach that level any time soon.
Member Since: Posts: Comments:
HURRICANE HENRIETTE DISCUSSION NUMBER 20
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082013
200 AM PDT THU AUG 08 2013

AN EYE HAS BEEN OBSERVED IN INFRARED IMAGERY DURING THE PAST SEVERAL
HOURS...ALTHOUGH THE CONVECTIVE CANOPY OF HENRIETTE IS SHRINKING.
THE WIND FIELD HAS ALSO SHRUNK BASED ON RECENT ASCAT DATA. DVORAK
CURRENT INTENSITY ESTIMATES ARE T4.5 FROM TAFB AND SAB...AND T4.2
FROM THE UW-CIMSS ADT...SO THE WINDS ARE BEING HELD AT 75 KT FOR
THIS ADVISORY. HOWEVER...WEAKENING APPEARS IMMINENT NOW THAT
HENRIETTE IS MOVING OVER WATER THAT IS COLDER THAN 26C AND IS
EXPERIENCING 10-15 KT OF SHEAR FROM THE WEST-SOUTHWEST. THE
OFFICIAL FORECAST CONTINUES TO SHOW WEAKENING AND IS MOSTLY
UNCHANGED FROM THE PREVIOUS FORECAST DURING THE FIRST 3 DAYS.
AFTER THAT...HENRIETTE IS EXPECTED TO BECOME A REMNANT LOW BY DAY 4
AND DISSIPATE BY DAY 5 WELL SOUTH OF HAWAII AS SHOWN BY THE GLOBAL
MODELS.

HENRIETTE IS GRADUALLY TURNING LEFT AND HAS SLOWED DOWN A BIT WITH
AN INITIAL MOTION OF 290/8 KT. A NARROW MID-LEVEL RIDGE IS
FORECAST TO TURN THE HURRICANE WESTWARD WITHIN 12 HOURS OR SO.
THEN...AS THE CYCLONE WEAKENS...LOWER-LEVEL FLOW IS EXPECTED TO
INDUCE A WEST-SOUTHWESTWARD MOTION BY 36 HOURS. THE TRACK GUIDANCE
IS IN RELATIVELY GOOD AGREEMENT THROUGHOUT THE FORECAST PERIOD...AND
THE NEW NHC FORECAST IS VERY CLOSE TO THE PREVIOUS FORECAST AND THE
MULTI-MODEL CONSENSUS TVCE.

ON THE CURRENT FORECAST...HENRIETTE SHOULD CROSS 140W INTO THE
CENTRAL PACIFIC HURRICANE CENTER AREA OF RESPONSIBILITY IN ABOUT 24
HOURS OR SO.

FORECAST POSITIONS AND MAX WINDS

INIT 08/0900Z 17.2N 137.4W 75 KT 85 MPH
12H 08/1800Z 17.4N 138.7W 70 KT 80 MPH
24H 09/0600Z 17.3N 140.5W 60 KT 70 MPH
36H 09/1800Z 16.8N 142.6W 55 KT 65 MPH
48H 10/0600Z 16.2N 145.0W 45 KT 50 MPH
72H 11/0600Z 15.3N 150.7W 35 KT 40 MPH
96H 12/0600Z 14.0N 157.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 13/0600Z...DISSIPATED

$$
FORECASTER BERG
Member Since: December 31, 1969 Posts: Comments:
1045. ackee
I think if the GFS and EuRO continue to show no real development throught next week I have a hard time believing this seasons will be a active year right now looks this year could be average year or maybe slightly below average That would really be GooDs news, but I know mother nature is unpredictable so we shall see
Member Since: Posts: Comments:
BULLETIN
HURRICANE HENRIETTE ADVISORY NUMBER 20
NWS NATIONAL HURRICANE CENTER MIAMI FL EP082013
200 AM PDT THU AUG 08 2013

...HENRIETTE GETTING SMALLER BUT HAS NOT WEAKENED QUITE YET...


SUMMARY OF 200 AM PDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...17.2N 137.4W
ABOUT 1170 MI...1885 KM E OF HILO HAWAII
MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...984 MB...29.06 INCHES
Member Since: December 31, 1969 Posts: Comments:



ABC blob


(The ABC islands are Aruba, Bonaire and Curacao.)
Member Since: December 31, 1969 Posts: Comments:
There has been little to no appreciable change in organization of Henriette since yesterday. However, the cyclone has shrunk somewhat over the past few hours. The hurricane will likely begin the weakening trend by later today as it is crossing the 26C isotherm.

Member Since: December 31, 1969 Posts: Comments:
SAL
Link
Member Since: Posts: Comments:
I think that huge mass of saharan dust went over Florida the last two days. The sun has been an eerie yellow/orange. Weather feels a bit "off" overall too, can't quite put my finger on it.
Member Since: Posts: Comments:
EP, 08, 2013080806, , BEST, 0, 171N, 1370W, 75, 984, HU
Member Since: December 31, 1969 Posts: Comments:
the only area where there are below average temps
Member Since: Posts: Comments:
all the blue in the Atlantic Caribbean an GOM almost gone! here we go season bout to get underway now.
Member Since: Posts: Comments:
Quoting 1013. GTstormChaserCaleb:
CMC 150 hrs. monsoon development taking time to consolidate moves over the Yucatan and emerges into the BOC:

150 hrs.



204 hrs.

Wasn`t this moving into the northern gulf instead of Mexico?Kori will be dissappoint :P lol.
Member Since: Posts: Comments:

Viewing: 1086 - 1036

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40Blog Index

Top of Page

Category 6™

About

Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather