Dr. Jeff Masters' WunderBlog

Which model do you trust? And, Arctic sea ice reaches a record minimum
Posted by: Dr. Jeff Masters, 17. elokuuta 2007 klo 19:33 (GMT) +3
Hurricane Dean, now a major Category 3 hurricane with 125 mph winds, continues to intensify and grow larger in size. Dean pounded Martinique and St. Lucia this morning, and claimed its first victim when a 62-year old man died on St. Lucia while trying to save his cow from raging flood waters.

Dean's eye is now visible on long range radar out of Puerto Rico. Buoy 42059 is in Dean's path, and should be interesting to watch.

We're fairly confident of the 1-2 day forecast, which has Dean headed west to west-northwest over the Central Caribbean, very close to Jamaica and the Cayman Islands, then into the Western Caribbean. After that, things become murkier. The latest 12Z runs of the NOGAPS, UKMET, GFS, and HWRF computer models all show Dean hitting the Yucatan Peninsula, and continuing on into the Gulf of Mexico towards a second landfall near or south of the Texas border. The HWRF run is slower, and does not take Dean to the coast at the end of its forecast period. The big outlier is the GFDL model, which now takes Dean northwest into central Louisiana. Which model is correct? The problem is that each model has a different solution for the behavior of an upper-level low pressure system expected to be over the Gulf of Mexico early next week. Which model should we trust?

In 2006, the official NHC forecast performed better than any of the individual computer forecast models. However, several "consensus" forecasts made using an average of the "big four" computer models (GFDL, GFS, UKMET, and NOGAPS), slightly outperformed the official forecast at some time periods (Figure 1). The Florida State Super-Ensemble (FSSE), for example, combines the "big four" models on the basis of past performance in an attempt to correct for biases in those models. (The FSSE is owned by a private company, which makes it available to NHC but not the general public). The Florida State Super Ensemble slightly out-performed the official NHC forecast at most forecast times.

The "big four" models are plotted on wunderground.com's computer model page for Dean, (along with the inferior BAMM model, which is plotted since it is always available quickly, and has done well at longer range forecasts in the past). We do not get tracking points for the ECMWF or HWRF models at this point, so you'll have to go the raw plots to see those forecasts. Note that three of the "big four" models performed well in 2006, with the GFDL and GFS performing the best. The UKMET had a very poor showing in the Atlantic in 2006. However, the UKMET was the best-performing model in the Eastern Pacific in 2006, along with the GFDL and BAMM models.

The European Center's model (ECMWF) outperformed the "big four" consensus models for 72, 96, and 120 hours forecasts in the Atlantic. However, the ECMWF model was generally not available in time to be used by forecasters. Efforts are being made to make the ECMWF available in a more timely fashion for the 2007 season, which would be a big help. We also have the new HWRF (Hurricane Weather Research Forecast) model this year. In tests done on a number of hurricanes for past years, the HWRF performed about as well as the GFDL (Figure 2).



Figure 1. Track forecast skill in 2006 of the official forecast and the various models, compared to a "zero skill" forecast using NHC's CLIPER5 model. The CLIPER model (short for CLImatology and PERsistence) is a model that makes a forecast based on historical paths hurricane have taken, along with the fact that hurricanes tend to keep moving in the direction they are going (i.e., their current motion persists). Note that many models had a negative skill for their 120 hour (5 day) forecast. The official NHC forecast had about 10% skill at 5 days. Image credit: NHC.

Figure 2. Track errors for 48-hour forecasts from the 2006 version of the GFDL model (black) and the new HWRF model (red). The HWRF model performed better on some hurricane than the GFDL, and worse on others. Overall, the two models had about the same performance on the cases tested. Image credit: Naomi Surgi, NOAA Environmental Modeling Center.

In conclusion, the official NHC forecast outperforms all the individual models, particularly at long ranges. Looking at the individual model plots can be helpful to determine the uncertainty in the forecast, but it's tough to beat the NHC. In the case of Dean, where one model is an outlier from the rest, it is usually better to believe the consensus of the other models.

If you want to look at plots of the individual models, I've written a description of the various models and where to find these plots on our tropical weather page.

Arctic sea ice shrinks to record low
The National Snow and Ice Data Center announced today that Arctic sea ice has just surpassed the previous single-day (absolute minimum) record for the lowest extent ever measured by satellite. Satellite measurements began in 1979. Sea ice extent has fallen below the 2005 record low absolute minimum and is still melting. Sea ice extent is currently tracking at 5.26 million square kilometers (2.02 million square miles), just below the 2005 record absolute minimum of 5.32 million square kilometers (2.05 million square miles). This new record was set a full five weeks before the usual late September minima in ice extent, so truly unprecedented melting is occurring in the Arctic. The most recent images from the North Pole webcam show plenty of melt water and rainy conditions near the Pole.


Figure 2. Current extent of the polar sea ice, compared to the normal for this time in August (pink line). Image credit: National Snow and Ice Data Center.

I'll have an update Saturday morning.
Jeff Masters

Hurricane Dean near the island Puerto Rico (Hector777)
the ciclonic surge hard mind in Salinas,Puerto Rico mines the Community Las Ochenta in the south of Puerto Rico
Hurricane Dean near the island Puerto Rico
Categories: Climate Change
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201. cormit 17. elokuuta 2007 klo 20:34 (GMT)    
Does anyone have a link to the recon flight data in real-time besides the report that comes out? I used one last year at weathermatrix.net/tropical/recon.shtml, which show the data from the plane every minute or so but it does not seem to be working this year. Thanks for your help.
202. diabeticstorm 17. elokuuta 2007 klo 20:34 (GMT)    
I agree with you welshcayman
203. wahooskipper 17. elokuuta 2007 klo 20:35 (GMT)    
There are two reasons the Florida mets are saying we need to keep an eye on this.

The legit reason: If things change to such a degree that we are in for some trouble there won't be a lot of time for preparations.

The real reason: They need to justify their existence since for the past 3 months they have gotten away with "highs near 90...chance of rain 50%."
Member Since: 17.08.2007 Posts: 0 Comments: 9
205. nolesjeff 17. elokuuta 2007 klo 20:35 (GMT)    
Posted By: StSimonsIslandGAGuy at 8:30 PM GMT on August 17, 2007.

Actually, since Dr. Master's talked about the melting polar ice in his blog, it is appropriate to talk about it in his blog.

Everytime the earth burps, the world is coming to an end due to the impact of man. I think it is pretty arogant to think WE make that kind of impact. And oh my god, we have been studying the impact of man soooo long that it is a proven fact. As Al Gore and the hollywood bandwagon makes millions on the crap he spews. sickening
Member Since: 20.06.2006 Posts: 9 Comments: 1391
206. TX 17. elokuuta 2007 klo 20:35 (GMT)    
looks like anyone on a cruise to Labadee, Haiti should be o.k.
207. obxrox 17. elokuuta 2007 klo 20:36 (GMT)    
pure speculation based on one model track, but assume the last gfdl comes to pass with landfall Tues evening in between what looks like Morgan City and Houma. Surfact winds look to be 130k in the NE quadrant, so Houma probably bears the brunt according to that model grid. Looks like 50-70k E winds across Lake Borgne into Lake P...What would that mean for NO and Laplace?

I hope none of this comes to pass and I'll be the next model run will have shifted.
209. auminer68 17. elokuuta 2007 klo 20:36 (GMT)    
Dropsonde wrote: I would say it's 99.5% likely that Florida is in the clear from a direct hit. I'm more worried at this point about Dean passing west of NOLA or making a direct hit on Houston.

100% agree.

I'm going to go out on a limb and assume that most folks here are mature enough to ponder the economic aftermath. OF COURSE I'm concerned about the human cost, but there are realities of the aftermath, too.

I'd say a direct hit on Houston is the worst case scenario right now overall.... I don't think people realize just how important that port is to the economy.

The oil&gas infrastructure (refineries especially) there is so fragile, that a direct hit from a cat5 would put gasoline prices up to $5 or higher... not to mention natural gas prices if enough gulf platforms are wiped out.


MAN I hate hurricane season.......
211. guygee 17. elokuuta 2007 klo 20:36 (GMT)    
I think all this talk of a "strong hurricane creates its own environment" is highly overrated. If a hurricane encounters a strong ridge or trough associated with a atmospheric planetary wave (Rossby wave) in the jetstream, the hurricane will be redirected or destroyed no matter how strong it is. "Creating its own environment" was the excuse for the failed recurvature forecasts for 1988 Hurricane Gilbert, but the fact is that that storm slid underneath any strong mid-latitude systems. Look at how easily Katrina and Floyd were weakened and brushed aside by troughs coming down from the mid-latitudes.
Member Since: 16.09.2005 Posts: 0 Comments: 2830
212. Metallica1990 17. elokuuta 2007 klo 20:36 (GMT)    
the only people safe from this thing are people living east of 60 degrees long. call ing anyone west of that 70% safe or more is out of there mind
213. H2PV 17. elokuuta 2007 klo 20:37 (GMT)    
Clobber-Time in TAIWAN. Your electronics gadgets just went up in price.

Typhoon SEPAT, Category 3/4 borderline, 132 mph winds, 161 mph gusts.

WATER VAPOR, IR. Look at the Greenhouse Gases!!!

http://www.h2-pv.us/wiki_100mpg/img/wiki_up/20070817.1856.SEPAT.jpg

JSL colorized version optimized to highlight rainfall intensity. Everything red is drowned. Philippines has had four days of flooding from this weather system and it was never directly hit.

http://www.h2-pv.us/wiki_100mpg/img/wiki_up/20070817.1856.SEPAT_jsl.jpg
http://www.h2-pv.us/wiki_100mpg/img/wiki_up/20070817.1856.SEPAT_jsl.jpg
214. coffeecrusader 17. elokuuta 2007 klo 20:37 (GMT)    
Here are my odds for an eventual landfall (for what it's worth): Mainland Mexico: 25%, Texas 45%, Louisiana 25%, Florida (panhandle and east) 5%. Only time will tell.
Member Since: 21.08.2006 Posts: 0 Comments: 254
215. nola70119 17. elokuuta 2007 klo 20:37 (GMT)    
Pretty much so Welsh I think the test will be around Jamaica thats where the big divergence is.....but who knows, maybe Dean will tip his hand in advance?

Florida is unlikely TV weathermen like ratings and they will exaggerate to get viewers-- its called a "tease."
Member Since: 16.06.2006 Posts: 0 Comments: 1535
216. CHAM0EBIAN 17. elokuuta 2007 klo 20:38 (GMT)    
you can really see how quickly Dean's growing when you watch the satellite loops in rock mode...and yeah, the arctic sst anomalies are very scary...
218. DeepintheHearta 17. elokuuta 2007 klo 20:39 (GMT)    
Why are people freaking out about this? I understand and agree that preparation well ahead of time is always advisable when thinking about hurricanes, and I also know full well that hurricanes, like weather in general, are nonlinear dynamical systems and are thus inherently unpredictable. (I grew up in S. Florida and had Andrew destroy my house).

Nevertheless, the best evidence we have right now -- which admittedtly is still quite imprecise beyond a 48-hr window and somewhat imprecise within that window -- suggests that landfall near the Houston/Galveston area is certainly not the likeliest possibility. The consistency and convergence of the models on the southward solutions buttresses this claim.

Just to be clear, none of this is to argue that preparation is inadvisable. But I am astonished to hear so many people alredy making disaster plans for a full-on Houston/Galveston hurricane.

(I live in Houston and am a full-time student in Galveston).
219. Rick54 17. elokuuta 2007 klo 20:39 (GMT)    
Florida meteorologists are saying to keep a close eye on the storm... and the best way to do that is to watch me live at 5 cause if my ratings go way up they will give me a raise.
220. Crisis57 17. elokuuta 2007 klo 20:40 (GMT)    
Posted By: nola70119 at 8:37 PM GMT on August 17, 2007.

Pretty much so Welsh I think the test will be around Jamaica thats where the big divergence is.....but who knows, maybe Dean will tip his hand in advance?

Florida is unlikely TV weathermen like ratings and they will exaggerate to get viewers-- its called a "tease."


guess Max Mayfield and Brian Norcross like to tease
222. Relix 17. elokuuta 2007 klo 20:40 (GMT)    
Posted By: DestinJeff at 8:36 PM GMT on August 17, 2007.
if dean gets to 16 before midnight, then something is fishy... looks to be 15.5 maybe 15.4 right now.


Actually, its around 15.2-15.3N. 15.6 would be too high right now. I still say that we might see a shift to the north in the 8PM advisory (not 5). The surroundings are changing, and some forecasted things don't seem to be going the way the NHC and models wanted. I am still waiting, I am confident its not coming to PR but I don't want winds over 40MPH or flooding rains.
Member Since: 3.08.2006 Posts: 0 Comments: 2358
223. fldude999 17. elokuuta 2007 klo 20:41 (GMT)    
Posted By: coffeecrusader at 8:37 PM GMT on August 17, 2007.

Here are my odds for an eventual landfall (for what it's worth): Mainland Mexico: 25%, Texas 45%, Louisiana 25%, Florida (panhandle and east) 5%. Only time will tell.


For what its worth i think the ULL will greatly influence Dean and I go along with GFDL-LA 25%, MS, 25%, FL panhandle (Pensacola) 40%..parts east of there 10%
224. hurricane10 17. elokuuta 2007 klo 20:41 (GMT)    
does anyone see on sat-img the more nw turn
225. Xion 17. elokuuta 2007 klo 20:42 (GMT)    
110 knots still.
Member Since: 29.08.2006 Posts: 0 Comments: 726
226. PalmHarbor 17. elokuuta 2007 klo 20:42 (GMT)    
Posted By: diabeticstorm at 8:20 PM GMT on August 17, 2007.
Florida is completely out of the woods now. Let's focus on the states in the Gulf.


Is it?
228. JLPR 17. elokuuta 2007 klo 20:43 (GMT)    
the eye is aso visible in then RGBSat
Member Since: 4.09.2007 Posts: 36 Comments: 5223
229. Metallica1990 17. elokuuta 2007 klo 20:43 (GMT)    
still at 125
230. extreme236 17. elokuuta 2007 klo 20:43 (GMT)    
yep winds are still 110kts, but it was expected, because if winds were to increase to the next step up (115kts) then it would end up being a cat 4 already. maybe tonight
Member Since: 2.08.2007 Posts: 19 Comments: 19234
232. sporteguy03 17. elokuuta 2007 klo 20:43 (GMT)    
No matter where Dean hits if it hits on the Gulf it will effect FL to Maine to Idaho to the small town in Indiana. The aftermath of a Cat 3-5 would be horrific, gas prices just skim the surface lets not get beyond that yet please thank you...hope it weakens.
Member Since: 7.07.2005 Posts: 0 Comments: 4824
233. thewebisode 17. elokuuta 2007 klo 20:43 (GMT)    
Florida is completely out of the woods now. Let's focus on the states in the Gulf.

Last time I checked the map, Florida was a state in the gulf.
Member Since: 15.08.2007 Posts: 0 Comments: 6
234. CFL 17. elokuuta 2007 klo 20:44 (GMT)    
WTNT24 KNHC 172038
TCMAT4
HURRICANE DEAN FORECAST/ADVISORY NUMBER 19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042007
2100 UTC FRI AUG 17 2007

A HURRICANE WARNING REMAINS IN EFFECT FOR GUADELOUPE AND ITS
DEPENDENCIES. THE WARNING WILL LIKELY BE DISCONTINUED LATER
TONIGHT.

A TROPICAL STORM WARNING REMAINS IN EFFECT FOR THE U.S. VIRGIN
ISLANDS AND PUERTO RICO.

A TROPICAL STORM WARNING ALSO REMAINS IN EFFECT FOR THE FOLLOWING
ISLANDS OF THE LESSER ANTILLES...MONTSERRAT...ANTIGUA...NEVIS...ST
KITTS...BARBUDA...AND ANGUILLA AND THE BRITISH VIRGIN ISLANDS. THE
WARNING WILL LIKELY BE DISCONTINUED LATER TONIGHT.

A TROPICAL STORM WARNING REMAINS IN EFFECT ALONG THE SOUTH COAST OF
THE DOMINICAN REPUBLIC FROM CABO ENGANO TO THE HAITI/DOMINICAN
REPUBLIC BORDER. A HURRICANE WATCH ALSO REMAINS IN EFFECT FROM CABO
BEATA TO THE HAITI/DOMINICAN REPUBLIC BORDER.

A TROPICAL STORM WARNING AND A HURRICANE WATCH REMAINS IN EFFECT FOR
HAITI FROM THE HAITI/DOMINICAN REPUBLIC BORDER TO PORT-AU-PRINCE.

AT 500 PM AST...2100 UTC...THE GOVERNMENT OF JAMAICA HAS ISSUED A
HURRICANE WATCH FOR JAMAICA. A HURRICANE WATCH MEANS THAT
HURRICANE CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY
WITHIN 36 HOURS.

AT 500 PM AST...2100 UTC...THE GOVERNMENT OF CUBA HAS ISSUED A
TROPICAL STORM WATCH FROM THE PROVINCE OF CAMAGUEY EASTWARD TO THE
PROVINCE OF GUANTANAMO. A TROPICAL STORM WATCH MEANS THAT TROPICAL
STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY
WITHIN 36 HOURS.

AT 500 PM AST...2100 UTC...THE HURRICANE WARNING FOR MARTINIQUE AND
DOMINICA HAS BEEN DISCONTINUED.

AT 500 PM AST...2100 UTC...THE TROPICAL STORM WARNING FOR ST.
LUCIA...SABA...ST. EUSTATIUS...ST. MAARTEN HAS BEEN DISCONTINUED.

INTERESTS ELSEWHERE IN THE CENTRAL AND WESTERN CARIBBEAN...INCLUDING
THE CAYMAN ISLANDS...SHOULD CLOSELY MONITOR THE PROGRESS OF DEAN.

HURRICANE CENTER LOCATED NEAR 15.0N 64.5W AT 17/2100Z
POSITION ACCURATE WITHIN 15 NM

PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 18 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 961 MB
EYE DIAMETER 15 NM
MAX SUSTAINED WINDS 110 KT WITH GUSTS TO 135 KT.
64 KT....... 25NE 20SE 20SW 25NW.
50 KT....... 60NE 60SE 30SW 70NW.
34 KT.......160NE 120SE 60SW 160NW.
12 FT SEAS..300NE 200SE 60SW 150NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 15.0N 64.5W AT 17/2100Z
AT 17/1800Z CENTER WAS LOCATED NEAR 14.8N 63.6W

FORECAST VALID 18/0600Z 15.5N 67.4W
MAX WIND 115 KT...GUSTS 140 KT.
64 KT... 25NE 20SE 20SW 25NW.
50 KT... 60NE 60SE 30SW 70NW.
34 KT...160NE 120SE 60SW 160NW.

FORECAST VALID 18/1800Z 16.4N 70.8W
MAX WIND 120 KT...GUSTS 145 KT.
64 KT... 30NE 20SE 20SW 30NW.
50 KT... 75NE 50SE 30SW 75NW.
34 KT...160NE 120SE 75SW 160NW.

FORECAST VALID 19/0600Z 17.3N 74.0W
MAX WIND 125 KT...GUSTS 155 KT.
64 KT... 30NE 20SE 20SW 30NW.
50 KT... 75NE 50SE 30SW 75NW.
34 KT...160NE 120SE 75SW 160NW.

FORECAST VALID 19/1800Z 18.0N 77.0W
MAX WIND 130 KT...GUSTS 160 KT.
50 KT... 80NE 50SE 50SW 80NW.
34 KT...160NE 120SE 80SW 160NW.

FORECAST VALID 20/1800Z 20.0N 84.0W
MAX WIND 130 KT...GUSTS 160 KT.
50 KT... 80NE 50SE 50SW 80NW.
34 KT...160NE 120SE 80SW 160NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 225 NM
ON DAY 4 AND 300 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 21/1800Z 22.0N 90.0W
MAX WIND 100 KT...GUSTS 120 KT.

OUTLOOK VALID 22/1800Z 24.5N 96.0W
MAX WIND 105 KT...GUSTS 130 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 15.0N 64.5W

NEXT ADVISORY AT 18/0300Z

$$
FORECASTER AVILA/MAINELLI

235. JLPR 17. elokuuta 2007 klo 20:44 (GMT)    
i would say its at 15.0 15.1
Member Since: 4.09.2007 Posts: 36 Comments: 5223
236. nola70119 17. elokuuta 2007 klo 20:44 (GMT)    
Destin, you are right, by Florida I meant South FL.....what I was trying to say is that right now there is no reason for anyone to think that the storm is headed to Jax or Tampa Bay. There are NO models that give any indication of that...
Member Since: 16.06.2006 Posts: 0 Comments: 1535
237. mostormspotter 17. elokuuta 2007 klo 20:44 (GMT)    
Why are people freaking out about this? I understand and agree that preparation well ahead of time is always advisable when thinking about hurricanes, and I also know full well that hurricanes, like weather in general, are nonlinear dynamical systems and are thus inherently unpredictable. (I grew up in S. Florida and had Andrew destroy my house).


I think that after 2005, folks started to realize that these storms can have effects on the entire nation. Living in Missouri, I am dreading the spike in gas prices, yet hioing to catch some major rain off of Dean. That said I would not be upset at all if it fizzled, but it is clear that such an event will not happen.
238. fldude999 17. elokuuta 2007 klo 20:45 (GMT)    
Posted By: PalmHarbor at 8:42 PM GMT on August 17, 2007.

Posted By: diabeticstorm at 8:20 PM GMT on August 17, 2007.
Florida is completely out of the woods now. Let's focus on the states in the Gulf.


The entire west coast and panhandle of FL IS in the gulf..if the ULL picks it up..my money is on the FL panhandle or Mobile, AL
239. floridafisherman 17. elokuuta 2007 klo 20:45 (GMT)    
rick, often the local weather people see things that the NHC doesnt. when charlie was making landfall, the NHC was predicting a tampa landfall up until 45 min before actual landfall in pt charlotte. our local weather guys caught that almost 4 hrs ahead of the NHC.

if they see something in that ULL that might effect deans path, then im watching it too.
Member Since: 28.08.2005 Posts: 0 Comments: 514
240. PalmBeachWeatherBoy 17. elokuuta 2007 klo 20:45 (GMT)    
by when should the track be clearer? cause so far nobody is sure
Member Since: 30.08.2006 Posts: 1 Comments: 433
241. CURIOUSWEATHERGRL 17. elokuuta 2007 klo 20:45 (GMT)    
I had to leave for a while...so I don't if my question was ever answered... what has to happen for the storm to turn more north towards LA/MS. Has the ULL moved at all?
Member Since: 1.08.2006 Posts: 0 Comments: 32
242. WPBHurricane05 17. elokuuta 2007 klo 20:46 (GMT)    
No one is out of the woods until this storm dissipates, even than were sometimes not out of the woods:


Member Since: 31.07.2006 Posts: 56 Comments: 7929
244. weatherboyfsu 17. elokuuta 2007 klo 20:46 (GMT)    

data from the Air Force hurricane hunter plane earlier today
indicated that Dean reached 110 knots. Next plane is expected to
reach Dean around 00 UTC tonight. Satellite images continue to show
an eye feature...numerous cyclonically curved convective bands
which are still affecting a large portion of the Lesser Antilles.
The outflow is well established in all quadrants. Although the
possibility of some fluctuations in intensity due to eyewall
replacement cycles could occur at any time...the shear is forecast
to remain low and the ocean temperature increases westward. This
would call for an overall upward intensity trend. This is
supported by the SHIPS....GFDL and hwrf intensity guidance.

Dean is moving toward the west or 280 degrees at 18 knots. The
steering pattern continues to be controlled by the high pressure
system to the north of the hurricane and the mid to upper-level low
over the southwestern Atlantic and Florida. This low is forecast
to weaken and move westward and be replaced by a ridge. This
pattern would maintain Dean over the Caribbean on a general
westward track across northern Yucatan and the western Gulf of
Mexico. The GFDL shows a more northwesterly track across extreme
western Cuba and the central Gulf of Mexico. While this solution is
outside the overall model guidance envelope...it can not be rule
out completely since this model has an excellent forecast track
history. The official track forecast is an update of the previous
one and follows the model consensus.

The bottom line is that Dean is expected to be a dangerous hurricane
through the next several days...and all interests in the Caribbean
Sea and the Gulf of Mexico should closely monitor the progress of
Dean.


Forecast positions and Max winds

initial 17/2100z 15.0n 64.5w 110 kt
12hr VT 18/0600z 15.5n 67.4w 115 kt
24hr VT 18/1800z 16.4n 70.8w 120 kt
36hr VT 19/0600z 17.3n 74.0w 125 kt
48hr VT 19/1800z 18.0n 77.0w 130 kt
72hr VT 20/1800z 20.0n 84.0w 130 kt
96hr VT 21/1800z 22.0n 90.0w 100 kt...inland
120hr VT 22/1800z 24.5n 96.0w 105 kt

$$
forecaster Avila

Member Since: 17.07.2005 Posts: 0 Comments: 1025
245. Xion 17. elokuuta 2007 klo 20:46 (GMT)    
Does anybody know the exact time (AST of course) the Hurricane Hunters will depart and/or reach the storm tonight?
Member Since: 29.08.2006 Posts: 0 Comments: 726
246. A4Guy 17. elokuuta 2007 klo 20:47 (GMT)    
I cannot believe they did not update the track!!!!!!!!!!!
Member Since: 23.06.2006 Posts: 0 Comments: 646
248. welshcayman 17. elokuuta 2007 klo 20:48 (GMT)    
Posted By: JFLORIDA at 8:42 PM GMT on August 17, 2007.

8am 14.4N 61.7W
11am 14.6N 62.6W
2pm 14.8N 63.6W

Then 15N 64.W? welsh?


Latest report from the NHC states the position as;

AT 500 PM AST...2100Z...THE CENTER OF HURRICANE DEAN WAS LOCATED
NEAR LATITUDE 15.0 NORTH...LONGITUDE 64.5 WEST

Therefore the movement in the past 3 hours is almost identical to the movement all day. Again, the current movement of the system is almost exactly what the NHC said it would be.
249. C2News 17. elokuuta 2007 klo 20:48 (GMT)    
5 day Track on NHC website is still from 1 pm...
Member Since: 17.07.2006 Posts: 73 Comments: 622
250. cormit 17. elokuuta 2007 klo 20:48 (GMT)    
stsimons, Agreed. I just didn't know if there was a website that showed this information. The storm that is on this site is an old storm. It was working last year. Any help??
251. sammo 17. elokuuta 2007 klo 20:49 (GMT)    
I think it's interesting to note that Dean will graze (may already be in) Hebert box #1 - as a cat3, of course. Will be interesting to see where it goes...
Member Since: 30.08.2006 Posts: 0 Comments: 149

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About JeffMasters
Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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