CAT 5 Hurricane Dean - Archived threads

[Evil Jeremy]

http://www.wunderground.com/tropical/tr ... _5day.html

[Wthrman13]

Lets say Dean is a cat 3 or 4 and crosses over the entire Yucatan Peninsula shouldnt that knock him down a bit before he gets to Mexico or Texas?

Yeah, see Emily, she hit as a 4 and weakened to a 1, but made final landfall as a 3.

There was Wilma which hit as a 4 but recovered nicely to hit FL as a 3, but there was also Isidore which hit as a strong 3 stayed for awhile and never recovered, even over the warm waters of the gulf.

Yep. The reason Isidore never recovered is that its inner core (including the deep convection) completely collapsed during its long stay over the Yucatan, leaving behind a very large wind field with very little low-level convergence into the core. Without that convergence, the wind field resembles that of a phonograph record, staying pretty much at the same radius relative to the center, and just spinning around and around until friction finally destroys the circulation. In order for Isidore to have recovered, it would have needed a substantial burst of convection near the center that would have provided enough low-level convergence to overcome this new balanced wind field. Once you already have a large-scale windfield like this with a lot of background angular momentum, this is physically very difficult to do, because of the tendency of the winds to centrifuge back outward. Given time, it might have had a chance.

In essence, if a hurricane is able to maintain its inner core wind field without losing low-level convergence it stands a much better chance of reintensifying upon moving back over water. Examples are Katrina over FL (which never really did weaken that much to begin with, and actually improved in organization, if not low-level wind speeds, over land), and Dennis over Cuba.

[Steve]

Get the Discussion Brent. I can't find it on any of the usual sources.

Hurry!!!!

Steve

[SaveNola]

http://www.wunderground.com/tropical/tracking/at200704_5day.html

Interesting they dont have it crossing 15N till Friday morning, if you would have told me that this morning when it had that apparent brief 290'ish heading, I would have said you're crazy.

[ConvergenceZone]

Man, if that track verifies, Yucatan is going to get slammed!!! I wouldn't even rule out a cat 5 ... How many times do we see a forecasted cat 4 end up being a 5 when all is said and done? While perfect conditions are needed to sustain a cat 5, I bet a cat 5 is possible for at least a few hours with this one....

[Brent]

TROPICAL STORM DEAN DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042007
1100 PM EDT WED AUG 15 2007

DEAN HAS CONTINUED TO GRADUALLY BECOME BETTER ORGANIZED THIS
EVENING...WITH A 2311 UTC TRMM PASS SUGGESTING THAT A SMALL BANDING
EYE FEATURE MAY BE FORMING. THE 00Z DVORAK SATELLITE INTENSITY
ESTIMATES WERE 55 KT...HOWEVER...THE SATELLITE APPEARANCE HAS
IMPROVED SINCE THEN AND THE ADVISORY INTENSITY HAS BEEN INCREASED
TO 60 KT.

THE INITIAL MOTION ESTIMATE IS 280/20. DEAN IS FORECAST TO CONTINUE
MOVING WEST TO WEST-NORTHWESTWARD SOUTH OF A DEEP-LAYER RIDGE
LOCATED OVER THE CENTRAL ATLANTIC. THE TRACK GUIDANCE IS TIGHTLY
CLUSTERED ON THIS MOTION DURING THE NEXT 72 HOURS. AT DAYS 4 AND
5...THE TRACK GUIDANCE HAS A BIT MORE SPREAD...BUT STILL IS IN GOOD
AGREEMENT ON A CONTINUED WEST-NORTHWEST MOTION INTO THE
NORTHWESTERN CARIBBEAN SEA. THE GLOBAL MODELS SHOW VERY LITTLE
INTERACTION BETWEEN DEAN AND A MIDDLE-LEVEL TROUGH CURRENTLY OVER
THE BAHAMAS...AS THEY CONTINUE TO MOVE THE TROUGH WESTWARD AHEAD OF
DEAN. THE NOGAPS IS A LITTLE SLOWER TO MOVE THE TROUGH WEST AND ITS
TRACK IS THEREFORE A LITTLE FARTHER NORTH THAN THE REST OF THE
GUIDANCE. THE NEW OFFICIAL TRACK FORECAST IS NEAR THE MIDDLE OF THE
GUIDANCE ENVELOPE AND CLOSE TO THE GUNA MODEL CONSENSUS.

THERE ARE SEEMINGLY FEW FACTORS THAT WOULD INHIBIT STRENGTHENING
DURING THE FORECAST PERIOD. AS MENTIONED IN THE PREVIOUS
DISCUSSION...THE MODELS UNANIMOUSLY DEVELOP A LARGE UPPER-LEVEL
ANTICYCLONE OVER DEAN AS IT MOVES INTO THE CARIBBEAN SEA.
MYSTERIOUSLY...THE GFDL AND HWRF MODELS HAVE BACKED OFF ON THEIR
RESPECTIVE INTENSITY FORECASTS. HOWEVER...THE SHIPS AND LGEM
MODELS CONTINUE TO INDICATE STEADY STRENGTHENING AND THE OFFICIAL
INTENSITY FORECAST IS UNCHANGED FROM THE PREVIOUS ADVISORY.

AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WILL BE
INVESTIGATING DEAN TOMORROW AFTERNOON...AND THE NOAA GULFSTREAM-IV
WILL CONDUCT A SYNOPTIC SURVEILLANCE MISSION FOR THE 17/00Z
ANALYSIS CYCLE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 16/0300Z 13.1N 50.2W 60 KT
12HR VT 16/1200Z 13.6N 53.2W 65 KT
24HR VT 17/0000Z 14.2N 57.2W 70 KT
36HR VT 17/1200Z 14.8N 61.1W 75 KT
48HR VT 18/0000Z 15.3N 64.7W 85 KT
72HR VT 19/0000Z 16.3N 71.5W 95 KT
96HR VT 20/0000Z 17.8N 78.5W 105 KT
120HR VT 21/0000Z 19.5N 85.5W 115 KT

$$
FORECASTER BROWN

[Derek Ortt]

what wrong with Dominica? How do they not issue a hurricane watch

Who is the met in charge there... is he asleep at the wheel or did he take lessons form the IMD?

[Chacor]

http://www.meteo.fr/temps/domtom/antill ... /princ.htm Meteo France
http://www.slumet.gov.lc/ Saint Lucia Met Service
http://www.weather.an/ Netherlands Antilles

[Praxus]

Yeah not looking too good for yucatan. Poor guys, I was there in december and you could still see serious vegetation damage from Wilma, even though they rebuilt the structures pretty well.

There is a TON of development going on all along the mayan riviera from cancun to tulum...lots of partially constructed buildings, which of course are ripe for hurricane damage.

[SouthFloridawx]

what wrong with Dominica? How do they not issue a hurricane watch

Who is the met in charge there... is he asleep at the wheel or did he take lessons form the IMD?

Yeah, that doesn't seem right.

[Evil Jeremy]

I can only say one thing: Emily.

Remember Hurricane Emily? the First Catagory 5 of 2005? This path is nearly exactly the same of Emily.

[JTD]

0Z models worth staying up for tommorow night. Gulfstream IV jet data will have been inputed into the models by then per NHC 11 P.M. discussion.

Can't wait!

[btangy]

what wrong with Dominica? How do they not issue a hurricane watch

Who is the met in charge there... is he asleep at the wheel or did he take lessons form the IMD?

Haha... just thinking the same thing. Perhaps they're getting their intensity estimates from New Delhi ... for those of you that remember uber-deep depression "Yemyin" =)

[Evil Jeremy]

Anyone else here up for a Hurricane at 2?

[Derek Ortt]

Now, I have a few not so nice words to say about the gov'ts of Barbados and ESPECIALLY Dominica this evening. If you are in Dominica... disregard the official information and act as if you are under a Hurricane Watch, which means hurricane conditions are POSSIBLE within 36 hours. This is most certainly the case here, I have no clue what they are thinking. Barbados also should be in a watch as the storm is likely only going to pass 50-70 miles north. Residents there should be aware that ther eis an outside chance of hurricane conditions within the next 36 hours.

Expect warnings by the gov'ts sometime between 5-11 a.m. tomorrow. I intend to ramp up coverage on nwhhc.com for those of you in the islands tomorrow morning, probably at 8 A.M. 9I would start at 5... but I'll likely just get up for a quick update and go back to sleep for nother hour ebfore heading into the office)

[RL3AO]

Anyone else here up for a Hurricane at 2?

Those are a long three hours...but I still say 5.

[Weatherfreak000]

I think actually this storm might only graze the Yucatan and move pretty much generally to the Central-Eastern Gulf Coast.


But it's impossible to tell these details so far out, I suppose they must forecast the ridge to be strong enough to barrel Dean into the Yucatan and hit MX/TX.

I'll be more influenced by this guidance if the GFS continues to show a pattern of this over the next two days.

[CronkPSU]

and kudos to all those pro mets who told us this thing would have to go pretty much due west in the next few hours, so much for those of us with eggs on our faces screaming it is a trend and going NW...whoops

[JonathanBelles]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

Advisory 081507

Today Tropical Storm Dean has strengthened to 70 mph and will likely become a hurricane. Tropical Depression 5 was upgraded to Tropical Storm Erin.



Southwestern North Atlantic...Tropical Storm Dean. Dean has strengthened to 70 mph and will be a Category 1 hurricane tomorrow. Dean is moving W or WNW at 23 mph. ALL Caribbean islands are in the cone of doom. It is forecast to explode into a Category 4 in 5 days!! A hurricane watch has been issued for many of the lesser Antilles and a Tropical Storm Watch has been issued for Saint Maarten. All those in the Caribbean should be preparing for a hurricane or a major hurricane. Recon will fly tomorrow into Dean. I do think the forecast will be shifted north a tiny bit in the coming days.

Northwestern Gulf of Mexico...Tropical Storm Erin. Erin is still hanging on to Tropical Storm Strength, but is quickly moving toward land for a landfall tomorrow morning or afternoon. Rain will be the major problem with Erin. A small amount of strengthening is possible in the next few hours. Landfall is likely near of Corpus Cristi. Tropical Storm Warnings are are out for most of the Texas coast. Those on the SW Texas coast should prepare for large amounts of rain, and a moderate wind. There has been a blow up of convection in the recent few frames from satellite. Do not feel that you cannot be affected by this storm.

Chances for Tropical Depression Development in next 3 days other than current storms: 0%
Chances for Tropical Storm Development in the Next 3 days: 0%
Possibility of hurricane development in the next 3 days:100%
US threat of Tropical development in next 24 hours: 100%

Amateur Forecaster Jonathan-Fact789

[jaxfladude]

Man, if that track verifies, Yucatan is going to get slammed!!! I wouldn't even rule out a cat 5 ... How many times do we see a forecasted cat 4 end up being a 5 when all is said and done? While perfect conditions are needed to sustain a cat 5, I bet a cat 5 is possible for at least a few hours with this one....

Dean 2007 as Gilbert Jr almost as strong as Gilbert Sr 1988????