Dean charges towards Jamaica; Erin returns

By: Dr. Jeff Masters , 3:37 PM GMT on August 19, 2007

Hurricane Dean continues to pound Haiti and the Dominican Republic with high winds and heavy rain, and is headed for a very close encounter with Jamaica and the Cayman Islands. Early this morning, winds at Barahona on the southernmost point of land of the Dominican Republic hit 52 mph, gusting to 104 mph. Sustained hurricane force winds are expected to remain well south of both Haiti and the Dominican Republic, but a major spiral band has brought extremely heavy rain to the south portion of both countries.


Figure 1. Microwave satellite image of Dean taken at 7:17am EDT Sunday August 19. Think of this as a weather radar in space--the red areas show where the most intense thunderstorms in the spiral bands and eyewall are occurring. Note the incomplete double ring of echoes around the dark blue eye. Dean has two eyewalls, concentric around each other.

Jamaica and the Cayman Islands
Jamaica is already receiving high winds and heavy rain from an outer spiral band. How bad will it get? The big question is if the eyewall will move over the island. Unfortunately for Jamaica, Dean has two eyewalls, forming concentric rings (Figure 1). The inner eyewall is 15 miles in diameter, and the outer eyewall is 37 miles in diameter. Winds of Category 3 and 4 strength are blowing in both eyewalls, as seen in the latest data from the SFMR surface winds taken by the Hurricane Hunters. So, Dean's center has to pass more than 25 miles south of Jamaica for the island to be spared the worst of the hurricane. The nation's capital, Kingston, lies on the southern portion of the island, and will be the hardest-hit major city. The tourist city of Montego Bay is on the northern part of Jamaica, and will fare much better.

The same story holds true for the Cayman Islands. Grand Cayman, the southernmost of the islands, it at greatest risk. If Dean passes more than 30 miles south of the island, they will miss seeing the outer eyewall of Dean and will fare relatively well. It's going to be a close call, but it appears that both Jamaica and the Cayman will miss seeing the eyewall of Dean.

Mexico and Texas
Mexico will not be so lucky, and will receive a double beating. Dean is expected to make landfall twice, once near the tourist havens of Cozumel, and then again south of the Texas border. Mexico has to hope that the steering currents will be kind and take Dean south of the most heavily populated regions of the Yucatan. Hurricane Emily of 2005 grazed the southern tip of Cozumel Island as a Category 4 hurricane with 135 mph winds, and Dean may follow a similar path. Mexicans can take heart in the fact that Emily caused no deaths in Mexico, and damage was surprisingly light. Most of the tourist regions were relatively unaffected by Emily--it was Wilma two months later that really punished the Mexican Riviera.

As for Texas, it looks right now like only extreme southern Texas near Brownsville needs to worry about Dean. Hurricane Emily hit 90 miles south of Brownsville as a Category 3 hurricane in 2005, and I expect a similar story will unfold for Dean. Emily brought sustained winds of about 40 mph to extreme south Texas, a 4-5 foot storm surge, eight tornadoes, and heavy rains. Damage was minor.

Links to follow:
Radar in Piln, Cuba.
Radar from Guantanamo Bay, Cuba.
Morphed microwave animation.
Kingston, Jamaica observations.
Montego Bay, Jamaica observations.
Grand Cayman observations.

After Dean, what next?
There is an area of disturbed weather that has formed off the northeast coast of South America, 400 miles southest of Barbados. Wind shear is 20-25 knots in this region, and will stay too high to allow develoment for at least the next two days. None of the reliable computer models are suggesting anything will develop over the coming week. The ITCZ region between Africa and the Lesser Antilles is relatively quiet.

Erin returns
The remains of Tropical Storm Erin re-intensified this morning into a major storm that slammed central Oklahoma with rains up to seven inches and wind gusts of tropical storm strength. The radar presentation of Erin's remains (Figure 2) looks remarkable tropical storm-like. I've saved a long animation of this "landcane". Numerous flood watches, flood warnings, and severe thunderstorm warnings have been posted for Oklahoma today.


Figure 2. The remains of Tropical Storm Erin re-intensified into a remarkably tropical storm-like cyclone today.

Typhoon Sepat
Typhoon Sepat has moved inland over mainland China, after hitting as a Category 1 storm. Earlier, Sepat hit Taiwan as a Category 3 typhoon. No deaths occurred on Taiwan, but at least 15 died in China--11 of them in a tornado spawned by the typhoon.

I'll have a full update Monday morning, and may have a short update later today.

Jeff Masters

Hurricane Dean South coast Antigua (RHLK)
Hurricane Dean South coast Antigua

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

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

Log In or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

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

Viewing: 1376 - 1326

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 | 28Blog Index

1376. LSU79
2:48 AM GMT on August 20, 2007
It looks to me that the ULL may be stalling or even moving slightly ENE on the latest water vaper loop.
Member Since: Posts: Comments:
1375. austxanne
1:58 AM GMT on August 20, 2007
beenthereinmiami

thank you. that was very helpful to me.
i appreciate it.
Member Since: Posts: Comments:
1374. quakeman55
1:59 AM GMT on August 20, 2007
I don't think this is over for the US. Not yet. It is still very possible that it can come ashore in Texas. Just wait till the models swing back north again.
Member Since: Posts: Comments:
1373. fldoughboy
12:51 AM GMT on August 20, 2007
I knew Florida was out of the picture about 4 days ago.
Member Since: Posts: Comments:
1372. Swells22
12:46 AM GMT on August 20, 2007
The ULL has no effect on Dean and high pressure is controlling it, Models continue pushing the track south. Belize just put up warnings. Get over it.
Member Since: Posts: Comments:
1371. bobcane
12:35 AM GMT on August 20, 2007
what was that thing that dean spit out on the last 2 sat images over Jamaica?
Member Since: Posts: Comments:
1370. Pedibrainpa
12:12 AM GMT on August 20, 2007
Looking at the satellite on nhc...from a very amature perspective...I can see that ULL sweeping Dean into the GOM. How real is that possibility?
Member Since: Posts: Comments:
1369. dsLATeach
11:51 PM GMT on August 19, 2007
rainraingoaway
again...maybe a silly question.....

could dean follow the ULL into the GOM nw? it looks to be heading to corpus...

i live sw of houston near the coast and am tired of rain and sure dont want to see dean! bless the people in its path

Not a silly question. Highly unlikely however living in south Louisiana you pay close attention to all tropical systems.
Member Since: Posts: Comments:
1366. GoofOff
7:49 PM EDT on August 19, 2007
In 36 to 40 hours Dean is scheduled to make landfall. After that, it really won't matter what is happening in the Gulf. The storm should lose most of it's punch. If you could visit the NHC in Miami and see all the data that is flowing into there, I think you would have a lot more faith in their projections. It is somewhat better than the dart boards some on here seem to enjoy.
Member Since: Posts: Comments:
1365. BeenThereinMiami
11:32 PM GMT on August 19, 2007
Hi Gang - The Upper Level Low (ULL), as has been pointed out several times the past two days, is out of the picture in terms of any influence on Dean. It is following its forecast movement to the west. It has also been mentioned by several other posters that Erin did not start out as an ULL and that that it is rare for a ULL to expand down to the surface and generate any tropical system.

Was the ULL and its position a concern previously in a possible influence to Dean's track ? Yes - if Dean had caught up to it. Is it anymore ? No. They are not even close enough to be on shouting terms let alone speaking terms.

The atmosphere is a 3-dimensional system with various scales of features both in the horizontal and the vertical. The different scales do interact, however even a hurricane as powerful as Dean can't shove its way through a strong, established high pressure system by itself.

When you are looking at the water vapor loop - which I'm happy to see - many of you have been - you must keep in mind that you are seeing a 2-dimensional image of the atmosphere. You can't tell - at least not without a lot of experience - from just looking at the moving features exactly where those features lie in the vertical which makes a difference when you are considering how the moving features will interact with each other - if at all.

Think of looking down on a highway interchange with multiple bridges and fly-overs. If the roads were transparent, you would not be able to tell from space whether one car was hurtling toward another on the same road or hurtling underneath or above it. To the untrained eye there are not "roadways" in the sky to tell you which features are crossing over, under or beside each other - or how "tall" each feature might be. Replace "cars" with various heights of buildings trucking along a transparent highway system with multiple levels and you will get what I mean. At least I think you will. :-)

Member Since: Posts: Comments:
1364. gatagus07
11:47 PM GMT on August 19, 2007
This one is way over for the US...every computer run is further south and south and south....although some of you still think Florida is still a possibility...LOL....y'all don't quit your day job....:)
Member Since: Posts: Comments:
1363. Baybuddy
11:44 PM GMT on August 19, 2007
Rainx2, I'm not sure... but I wouldn't let my guard down.
Member Since: Posts: Comments:
1361. hosweather
11:37 PM GMT on August 19, 2007
The MM5 model from FSU shows the ridge in the Gulf weakening over the next few days and shifts Dean's track way to the North. Also the HWRF which used to have one of the most southerly tracks now shows Dean moving strongly to the north once he is past the Yucatan. It's not over yet.
Member Since: Posts: Comments:
1360. rainraingoaway
5:40 PM CST on August 19, 2007
3rd times the charm?????

again...maybe a silly question.....

could dean follow the ULL into the GOM nw? it looks to be heading to corpus...

i live sw of houston near the coast and am tired of rain and sure dont want to see dean! bless the people in its path.......
Member Since: Posts: Comments:
1359. sflhurricane
11:41 PM GMT on August 19, 2007
That feeder band is the boundary layer
Member Since: Posts: Comments:
1358. flibinite
11:34 PM GMT on August 19, 2007
Wow... is Dean developing a feeder ban all the way out at Long. 85? Could that be a feeder band that far out in front of it? And look at what's happening in Cuba. It's difficult to see how Dean isn't going to get even huger when it clears Jamaica, no matter what direction it ends up taking. :-((

Jo
Member Since: Posts: Comments:
1357. Baybuddy
11:36 PM GMT on August 19, 2007
I won't believe anything till its in the books.
Member Since: Posts: Comments:
1356. Chicklit
11:30 PM GMT on August 19, 2007
Yes, Pottery...very serious there. Kmanislander and WelshCayman have been preparing for days. I hope to see them post on here again soon! I think the rugby tournament is canceled for tomorrow.
Member Since: December 31, 1969 Posts: Comments:
1355. WXMongrel
11:33 PM GMT on August 19, 2007
BlueWaterblues...I have a similar opinion. Earlier today I mentioned that the East Cost high was "behind the curve" and that the GOM ULL was running interference for Dean. Upper level winds seem to indicate that West of Jamaica, the steering looks to be northerly. I'm not a forecaster but was an aerographer in the Navy and observation rather then modeling is a more realtime and precise approach.
Member Since: December 31, 1969 Posts: Comments:
1354. StormJunkie
11:36 PM GMT on August 19, 2007
Dr M has a new blog up
Member Since: December 31, 1969 Posts: Comments:
1353. katadman
11:33 PM GMT on August 19, 2007
One thing that bothers me about the current models and the NHC track is that they seem to indicate a strong chance of a mainland landfall just north of Vera Cruz. I know that coastline and there is a nuclear power plant built right on the coast (not two hundred yards off of the GOM). That's plenty scary for me, even though I know those things are built like a fortress.
Member Since: Posts: Comments:
1352. taco2me61
11:27 PM GMT on August 19, 2007
Posted By: jake436 at 11:16 PM GMT on August 19, 2007.

Posted By: taco2me61 at 5:09 PM CST on August 19, 2007.

Mobilebayrat,
The answer is yes.... With the way the storm is coming in, the storm surge will be high from Corpus Christy Tx to Brownsville Tx


Not exactly...Of course it would depend on how far south of the border it hit. But the main thing is...and I would think that someone with MobileBay in their screenname would know this...is that the MS and Mobile Bay areas are more susceptible to surge than anywhere else along the Gulf Coast...due to the shallow shelf. Also, Mobile Bay is situated so that the mouth of it acts as a funnel for northward moving surge...which is what Katrina brought. Also, Dean...as impressive as he is...isn't nearly the physical size of Katrina...so the affected area won't be as large. Of course, there is plenty of time for Dean to grow...both in strength and size...but it's unlikely he will attain the physical size of Katrina.

Yes I do know that Mobile is the most northern on the Gulf Coast but with all due respect if the storm comes in at an angle such as Dennis or Ivan there was no storm surge.... Also with Cindy we also had no storm surge which took the same path as Katrina... Now I understand that those other storms were not as big as Katrina but could had some kind of surge...
Even Camile nor Fredrick had the Surge of what Katrina and they were even closer..... I think it has alot to do with the Angle of the storm...

Just my 2 cents worth and it even is not worth that much....

Member Since: Posts: Comments:
1351. sflhurricane
11:34 PM GMT on August 19, 2007
JPhurricane.. besides the CMC model, what other models are developing that area of thunderstorms?
Member Since: Posts: Comments:
1350. CajunSubbie
11:33 PM GMT on August 19, 2007
funny.. if it does somehow turn north? what do we debate then? since we can't debate where its going?
Member Since: Posts: Comments:
1349. medic11402
6:26 PM CDT on August 19, 2007
Ok here is some raw analysis...

From Point of Origin to 1000 miles Dean avg heading of 274 degrees

from 1001 to 2000 miles Dean avg heading of 276 degrees

from 2000 miles to current position Dean has avg a heading of 281 degrees

Forecast position alignment
at 281 degrees to the yucaton slightly north of NHC track, and to NC predicited Landfall in Mexico is right on for a heading of 281 degrees from current position.

The southern tip of Texas would require a change in heading of 11 degrees to the north at 292 degrees. This is 244 nautical 281 statue miles north of the predicted Mexico impact.

to Houston Texas would require a heading change of 22 degrees to 303 degrees. This is 493 nautical 567 statue miles north of the predicted impact area in Mexico.
Member Since: Posts: Comments:
1348. ChuckieTodd
6:31 PM CDT on August 19, 2007
Posted By: swlouisianagirl at 6:31 PM CDT on August 19, 2007.

With that said someone please tell me is there ANY chance of this monster hitting Louisiana. We stayed for Rita, but will not stay for the next one.


You're asking the wrong bunch. I'm sure we can find somebody to post that LA is still a possibility. I'm standing by the NHC.
Member Since: Posts: Comments:
1347. Baybuddy
11:31 PM GMT on August 19, 2007
Wait and watch young grasshopper...
Member Since: Posts: Comments:
1346. sflhurricane
11:31 PM GMT on August 19, 2007
Swlouisianagirl, You are safe from Dean.. NO WAY it turns North and gets into the Gulf.. Theres a building area of High pressure protecting the Gulf States
Member Since: Posts: Comments:
1345. rainraingoaway
5:31 PM CST on August 19, 2007
still just the little mouse in the corner that nobody's paying attention to....:)
Member Since: Posts: Comments:
1344. Xion
11:31 PM GMT on August 19, 2007
Yes, new blog is up. Everyone move there.
Member Since: December 31, 1969 Posts: Comments:
1343. rodrigo0
11:30 PM GMT on Agosto 19, 2007
RULE NUMBER 1: NEVERMIND TEXAS. DEAN WILL NOT HIT TEXAS, THE STATES.

RULE NUMBER 2: DEAN WILL HIT MEXICO 2 TIMES, HOW MUCH STRONG? WE DONT KNOW, WE ARE HERE FOR TO DEBATE THIS.
Member Since: Posts: Comments:
1342. swlouisianagirl
11:23 PM GMT on August 19, 2007
I do not wish a hurricane on anyone. I know the models show it hitting Mexico, but living in a Gulf Coast state makes me nervous right now. We live almost 90 miles inland and still hurricane Rita was very bad. Trees were crashing all around us and we weren't sure if our roof was going to hold. Thankfully it did and we were lucky to have only $14000.00 in damages. With that said someone please tell me is there ANY chance of this monster hitting Louisiana. We stayed for Rita, but will not stay for the next one.
Member Since: Posts: Comments:
1341. centex
11:20 PM GMT on August 19, 2007
It's Gilbert revisted only slightly south. Current track taken out 4 days is only a little north of current cast because they expect turn from WNW to more W. My guess would it will be more presistent in the WNW track.
Member Since: Posts: Comments:
1340. sflhurricane
11:28 PM GMT on August 19, 2007
Blue... You couldnt be anymore wrong... High Pressure is SHIELDING the US from Deans wrath
Member Since: Posts: Comments:
1339. JPV
11:26 PM GMT on August 19, 2007
You guys that are fawning all over how accurate the NHC forecasts are just plain cracking me up.

Don't you realize that the NHC is constantly changing their forecasts all the time?

Look at the "accuracy" of these tracks...

01

Ooohhh... look! It's headed north of Puerto Rico!


02

It's headed straight for Haiti and then it's gonna shoot north of Jamaica and squeeze right in between there and Cuba!


02

LOOK OUT! Direct hit on Jamaica, then it will scrape the tip of the Yucatan Peninsula, and end with a Mexico/Texas border landfall!


02

LOOK OUT! It's gonna pass by the south of Jamaica, then have a direct hit on the Yucatan Peninsula, and end with a Central Mexico landfall!

Yeah, it's REAL accurate... as long as you ignore all the times that it's been altered.

LOL!
Member Since: Posts: Comments:
1338. sflhurricane
11:27 PM GMT on August 19, 2007
JPhurricane.. besides the CMC model, what other models are developing that area of thunderstorms?
Member Since: Posts: Comments:
1337. SWFLdrob
11:26 PM GMT on August 19, 2007
blue...

so why has Dean moved nearly dead west the last couple of frames?
Member Since: Posts: Comments:
1336. hurricane667
11:27 PM GMT on August 19, 2007
when does recon go in. they will probably find a cat 5
Member Since: Posts: Comments:
1335. Stormy2day
7:26 PM EDT on August 19, 2007
blue,
do you have anything to post that shows this north turn?
I don't see it - what I see is Dean is going to head further south than projected. not north.
Member Since: Posts: Comments:
1332. jake436
5:23 PM CST on August 19, 2007
Posted By: seafarer459 at 5:22 PM CST on August 19, 2007.

Roman ,

Northern eyewall on shore???
Did not look that way to me on the floater..


He said the EyeWALL...not the eye. The eyewall is definitely onshore in Kingston...they are experiencing 114mph sustained winds, with gusts to 138mph. The eyeWALL isn't the eye...it is the wall around the eye.
Member Since: Posts: Comments:
1330. 900MB
11:26 PM GMT on August 19, 2007
Thanks Chicklit!
Member Since: Posts: Comments:
1329. sngalla
7:25 PM EDT on August 19, 2007
Local mets on evening news said that we need to keep a close eye on the wave. Shear is forecasted to drop as it enters the Caribbean in the next 24 to 36 hrs.
Member Since: Posts: Comments:
1328. will40
11:22 PM GMT on August 19, 2007
Taz i dont see anything there to turn it north. I dont see the ULL doing that. probably seeing a wobble but not a turn. Once the ULL is gone a strong high will replace it IMO.
Member Since: Posts: Comments:
1327. saltydog1111
11:25 PM GMT on August 19, 2007
I've been lurking/reading these posts and never known Taz to hype things up.....
Member Since: Posts: Comments:
1326. pottery2
7:22 PM AST on August 19, 2007
Chicklit, Our friends in the Caymans must be under heavy manners now. My nephew flew in there yesterday, ( Foolish ) to play in a rugby tournament starting Monday. Apparently, they all managed to get out today, back to Miami. ( crazy )
Member Since: Posts: Comments:

Viewing: 1376 - 1326

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 | 28Blog Index

Top of Page
Ad Blocker Enabled

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

JeffMasters's Recent Photos

Mountain wave clouds over Labrador
Mountain wave clouds over Labrador
Mountain wave clouds over Labrador
Labrador ice