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Dean pounds Martinique; Erin soaks Texas; Sepat zeroes in on Taiwan

By: Dr. Jeff Masters, 2:07 PM GMT on August 17, 2007

Hurricane Dean plowed into Martinique this morning as a Category 2 hurricane with 100 mph winds. Radar imagery from Meteo France (Figure 1) shows that the eye of Dean grazed the southern tip of Martinique at about 5am EDT this morning. Winds at the Martinique airport gusted as high as 89 mph, but the airport was north of the eyewall, and missed seeing the calm at the center (Figure 2). An intermediate report, not sent out as part of the regular observations received by wunderground, showed sustained winds of 75 mph, gusting to 103 mph, at 4:42am EDT. The airport is still sending in observations, which is a good sign, and it is likely that only the southern 1/4 of the island suffered heavy wind damage. The northern part of St. Lucia also suffered heavy wind damage, and Dean's winds lifted the roof off the pediatric wing at Victoria Hospital in St. Lucia's capital, Castries. Dean underwent a brief period of weakening just before hitting Martinque, thanks to some dry air intruding into the circulation, so may have brought only Category 1 winds to Martinique. The rains continue on the island this morning, and current radar imagery shows that Dean has intensified since departing Martinique. This is backed up by the 9:12am EDT Hurricane Hunter data, which found the pressure had dropped to 965 mb and the surface winds had risen to 105 mph. Dean's rainbands are dumping torrential rains on Martinique and Dominica, and life-threatening flooding and mudslides will be a major hazard on those islands today.


Figure 1. Radar image of Dean as it passed over the southern tip of Martinique. Image credit: Meteo France.


Figure 2. Current conditions for Friday, August 17, 2007 at Le Lamentin, Martinique. This airport is on the sheltered west side of the island, by the capital city of Fort de France, and was far enough north that the eyewall missed.

Latest model runs
The NOAA jet flew last night, collecting a large amount of high-quality data around Dean's environment that was used to initialize the latest (06Z) model runs. These models continue to unanimously show a grave threat to Jamaica and the Cayman Islands two days from now. Even if Dean misses these islands, it won't be by much, and residents should expect hurricane conditions, as Dean should be an extremely dangerous Category 4 storm by then. Haiti and eastern Cuba also appear likely to suffer severe flooding problems from Dean's outer spiral bands, but a direct hit in these areas appears unlikely. Lesser flooding problems, but still potentially life-threatening, will occur in Puerto Rico and the Dominican Republic. Additionally, Dean may grow so large and powerful that its spiral bands will cause heavy rains and flash flooding in Venezuela, Nicaragua, and Honduras. Hurricane Gilbert of 1988, which traced out a similar path, was large enough to cause several flooding deaths in each of those nations.

The NOAA jet mission did not help at all with narrowing down the uncertainty in the computer forecasts for the 4-5 day period, which remain divergent. The 06Z run of the GFS model takes Dean over the center of the Yucatan, then into the Texas/Mexico border region on Thursday. The 06Z GFDL is much faster and further north, taking Dean through the Yucatan Channel and into northeastern Texas near Galveston on Wednesday. The 06Z HWRF is in between and much slower, taking Dean over the tip of the Yucatan Peninsula by Wednesday. 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, and there is no is currently no way to guess which model will be right. Which model should you trust? I'll present the statistics for how these models performed last year in my update this afternoon.

Erin leaves a Texas-sized mess
Tropical Depression Erin continues to dump heavy rain on Texas, with another 2-5 inches expected today in west Texas. Erin dropped over 10 inches of rain near San Antonio, and areas near Houston received nine inches (Figure 3). Over 70 high water rescues were performed in the Houston area from Erin, and four people died in Texas due to flooding. The region encompassing Corpus Christi, Austin and Houston has already surpassed its average yearly rainfall total, with 40-48 inches having fallen. Erin's rains could be setting the stage for a major flooding disaster next week in Texas, should Hurricane Dean hit the state and dump heavy rain of its own. With Erin's rains leaving the soil saturated, Dean's rains will have nowhere to go.


Figure 3. Radar estimated precipitation from Tropical Storm Erin.

Super Typhoon Sepat
In the Western Pacific, residents of Taiwan are preparing for the arrival of Typhoon Sepat, which is expected to hit the island Saturday morning local time. Sepat is no longer a Super Typhoon, thanks to an eyewall replacement cycle it underwent yesterday. Still, the storm has a huge eye about 70 miles in diameter that will bring Category 3 or 4 winds to a large area of Taiwan. An impressive microwave image of Sepat's eyewall replacement is available from the Monterey NRL web site.

I'll have an update around 4pm EDT this afternoon, when I'll discuss which long-range computers model forecasts of Dean we should believe.

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

1001. yamil20
am very concerned because i have family on the isle of youth in cuba,if dean hits cuba,that would be a huge catastrophic!!
"Every Major Hurricane that passed through Box 2 late in the year hit florida"

I don't think this box applies to August, right?
1003. Relix
Hmm.. what kind of winds and rain could we receive here in PR if the system keeps strengthening that way, and lets hypothetically say it makes a sudden northward move then west... that would put us in the TS winds range, right?
1004. Shrap
Posted By: Thaale at 5:19 PM GMT on August 17, 2007.

Posted By: Shrap at 5:13 PM GMT on August 17, 2007.

According to the CIMSS data, the ULL by Florida has only moved 1degree west in the past three hours.

That makes it about only 3 degrees west (and slightly south) on the day.

shrap, could you walk us through your reasoning? 1/3 hrs = 8/day = 24/3 days.


Sorry for the confusion. It hasn't been moving at a constant rate. I just looked at where the 200mb low started (at 0z today), and where it ended (at 15z). The total difference today has been about 3 west (and about 3 south).
1005. Drakoen
Posted By: ClearH2OFla at 6:34 PM GMT on August 17, 2007.

so that means a continued west track correct.


yea..
There are a lot of New Orleans scenarios......from something that comes up the river (worst) to a slow moving Cat 3 that hits Morgan City and refloods most of the city, etc.

But we are way too far out to discuss but the GFDL has been in the exact same area for two days straight whereas the other models are now oscillating.....what this means to me is that you can throw the models out completely for a few days.

None of the pros are going out on a limb here--
With all of these storms, the center of strongest winds is a narrow area..However, as most of us know, the bigger problem often becomes the tornadoes which usually accompany a landfaling hurricane in the NE quadrant...In a very strong storm, eyewall area is the total devastation and the damage decreases as you get further out...But the greatest problem, other than surge at the coast, is of course the copius amount of rain......Here in the Big Bend of Florida, with all of our trees, we would much prefer a fast moving hurricane which will "snap" a lot of tree limbs as opposed to a "slow soaker" with lots of rain....With these the ground can saturate for over 24 hours, and with a 60 MPH gust, trees start toppling over onto homes and vehicles....
Where do you get that dropsonde data? Can someone provide a link? Not the one on the NHC site either...but the one that people are saying is already making Dean a Cat 4.
1009. marker
cmc and nogaps show south of the border landfall


the rest show on or north of the border landfall
Posted By: SavannahStorm at 6:32 PM GMT on August 17, 2007.

Surface: 957 mb; Temp: 76F; Dewpt: 73F; NNW (340) @ 138 mph


Surface-level winds folks. Cat. 4...


I single instantaneous observation does not make a cat 4. Hurricane winds are time averaged at 10 meters elevation. That dropsonde could have fallen through a gust front, the left overs from a downburst, etc.
SJ- I started having the same problem the last time I had a Windows auto-update. I dunno what causes it, but I just use Firefox to watch the Java loops instead of IE.
It seems every time I take a break dean strengthens..i went 4 lunch a cat 2 got back a its a cat 3...maybe a go sleep tonight its a cat 3 wake up a cat 4
1014. IKE
12Z HWRF aims Dean at SE Texas...gets the pressure down to 894mb's on it's run thru the GOM....

Link
I don't think this box applies to August, right?

Usually applies later in the season, around September, October. Storms like Charley, however, have hit Florida after Hebert box 2 interaction in August.
SJ- I'm having trouble with the loops too. AndI think you meant right:) Not left... With GFDL
it's gfdl vs gfs. both have held steady for more than a few runs now (the gfdl doesnt know how north to go but it is north). advantage goes to the gfs right now as it has other model support and has been consistent longer
1018. JAC737
Could you please tell me if this hurricane is moving faster than most?
SS, I am using FireFox...It don't make no since. It is strange that it sort of coincides with another java app I used recently...
1020. Drakoen
storm junkie. I have had the same issues with java. I think it is a glich with the new version. I had to close out of my browser and get back in and when you log back in open a java loop for example and keep it open or minimize it. You should be able to access Jave there after intil the next time you log in. Good luck.
1022. JRRP
NOW DEAN MOVE NW
TAKE CARE
Posted By: StormJunkie at 2:37 PM EDT on August 17, 2007.
SS, I am using FireFox...It don't make no since. It is strange that it sort of coincides with another java app I used recently...


same here. a few times the loops have locked up firefox on my pc.
1024. jrhms08
I agree hurricaneparty. The nation won't be nearly as sympathetic to a hurricane hitting New Orleans. So much money spent for a state and city with so much corruption and mismanagement.
1025. genha
I think the GFDL model is a little extreme after Dean enters the Gulf; I DO believe Dean will be closer to Cuba and the other islands than the other models suggest; I just hope it doesn't slice through Louisiana. The state cannot handle another hit from a major storm right now. Probably could say that for the next decade, too.
1026. A4Guy
Have not seen much of TexasCaneCaster 9and associated dramatics) on here lately.
Maybe he is off surveying the devastation caused by Erin? lol
My family has been in south La. for over 200 years one more big hit and it's time for this Cajun to head north.
deans winda re up to 125 mph cat 3 gusts to 155
I may just not be seeing it right but it looks to me like what's coming down from the northwest west of the low off florida and Dean moving as fast underneath it's shutting the low off or keeping it from going west.
It sure isn't moving fast enough for me right now and gives the GFDL merit. That low needs to go west and get the heck out of there.
i also realize dean is slowing down a bit from 24, 23 now 22 mph

REPEATING THE 145 PM AST POSITION...14.8 N...63.6 W. MOVEMENT
TOWARD...WEST NEAR 22 MPH. MAXIMUM SUSTAINED WINDS...125 MPH.
MINIMUM CENTRAL PRESSURE...961 MB.
1031. IKE
It's going slightly north of the tropical forecast points...appears headed for the southern coast of Haiti...

Link
java has mad a few updates recently, Ive noticed problems especially when more than one loop is open at a time.
Weather456...Dean was moving 21 mph earlier...it's back up to 22..
Personally, I think the NHC is playing the percentages. And the percentages favor a Yucatan landfall and S Tex/Mex 2nd landfall. There are too many ifs and buts with that upper low and if Dean can keep moving fast enough to get caught up in it. Why bet on all that when half of the model consensus simply shows a high will build north of Dean keeping it moving west.
Posted By: A4Guy at 6:39 PM GMT on August 17, 2007.
Have not seen much of TexasCaneCaster 9and associated dramatics) on here lately.
Maybe he is off surveying the devastation caused by Erin? lol


the word on the street is that he's part of the 'banned bunch'
1037. yamil20
in my opinion i think that the florida keys will be the first strike and then the florida panhandle,at 5 pm the forescast cone should include the keys,florida dont let the guard down wait a little bit.
1038. Drakoen
Posted By: IKE at 6:40 PM GMT on August 17, 2007.

It's going slightly north of the tropical forecast points...appears headed for the southern coast of Haiti...

Link


yea IKE perhaps north of due west. If it keep strengthening it can go further north. That upper level low is also gonna help with the motion.
1039. IKE
CNN just talked about it going north of the tropical forecast points. Their met(Chad Myers), just showed it.

Appears to be following the GFDL path...so far.
anyone noticing that after each advisory the forecast points are being shift SLIGHTLY north or is it just me seems the storm is north of the forcast points again
Who are these virtual machines and what are they doing on my pc???

THanks lf you are correct, I meant right...Just really frustrated right now. If anyone has any info on why virtual machines would be running java on my pc please wu me.

I am off to try and solve this problem, in the meantime.

If you are looking for forecast models, imagery, marine data, wind data, preparedness info...
Quick Links

Sorry y'all wish I could stick around!
1042. Daveg
More panic...models already take it near the southern coast of Haiti anyway, and I think it is staying pretty much on that track at the moment. I don't think it will hit Haiti, and I sure hope that is right.
so if the ULL off floridas east coast moves W, will that act to draw Dean more north?
Posted By: MississippiWx at 6:41 PM GMT on August 17, 2007.

Weather456...Dean was moving 21 mph earlier...it's back up to 22..


if that is so..then my bad
1045. jrhms08
Anyone know when the low's drop dead time is to start heading west to prevent Dean from turning to the NW?
News reports from Dominica confirm 1 fatality, and structural damage to buildings. Agriculture has been severly hit. Bananas are a big part of the economy. For info., it takes 18 months for a banana plant to produce fruit, and they are easily flattened by even a 40 mph gust. So goodbye Dominica Bananas.
Mr. Chiquita Banana Co. will be very pleased............
1047. IKE
Posted By: Crisis57 at 1:43 PM CDT on August 17, 2007.
anyone noticing that after each advisory the forecast points are being shift SLIGHTLY north or is it just me seems the storm is north of the forcast points again


Yup...it is.
Hey Drakoen what is the update with the trouf is it moving?
1049. Drakoen
Weakness caused by the ULL.
957 going to 871...before the hot gulf
1051. quante
Who ever first mentioned the Hebert box should be banned.LOL

On a serious note, the GFDL is verifying as most accurate track so far (go here Link and click on best track, redraw map), so that is troubling. A few days ago, it was way off though, showing track due west when other models had shifted to W, then WNW.

Have to see what the next run shows.
crisis u still with me on this? is my predicts panning out?
But if that ULL doesn't get its arse in gear, the GFDL could come to fruition. And then doom and gloom for Upper Texas & Louisiana.
1054. TXMET
I was wondering. Regarding the ULL, is the barometric hole it creates for Dean a more significant factor or the direction of its winds? If the hole is more important, then the proximity of Dean to the ULL is most relevant. If the direction of the winds around the ULL is more important, then the longitudinal position of Dean relative to the ULL is most relevant. Any thoughts?
The GFS and CMC are both hinting at two more storms coming into the gulf in the next week or two. Interesting
1056. Rlennon
Anyone know when the low's drop dead time is to start heading west to prevent Dean from turning to the NW?


Someone posted 00z or 12z tomorrow

1057. Daveg
It not going to be enough weakness for a long pull North (thank goodness), the ULL is already starting to pull NE and away in the WV loops.
looks like dean will be moving more north than west for today so far
Vero What is your PRedict?
no one is betting on anything at this point. but it was just last year that all the models had ernesto in LA.
Posted By: VEROBEACHFL1 at 6:45 PM GMT on August 17, 2007.

crisis u still with me on this? is my predicts panning out?


we can only keep monitoring it but by the looks of the graphic that Drakoen posted seems that Dean is close to the weakness of that high
1062. IKE
Posted By: Daveg at 1:46 PM CDT on August 17, 2007.
It not going to be enough weakness for a long pull North (thank goodness), the ULL is already starting to pull NE and away in the WV loops.


Pull NE? It's drifting west....the one east of Florida.
Drak,
Can any land interaction with Haiti throw the track off further some models have it dangerously close to the shoreline of Haiti.
Below, if I copied it correctly, is the link to the daily computer models for Katrina from about 5 to 6 days before the storm hit. The GFDL was one of the more accurate it seems to me.

Please note I am a weather novice but a very anxious bystandered. I spent 19 days last time without power. Would rather not repeat that again.


http://www.wunderground.com/hurricane/at200511.asp?feature=verification
i have been saying a more northernly track than the models since 3 days ago.......... and a possible sharper northern sometime b4 80w---but with that --time will tell
TXMET- think of the ULL as a big whirlpool. When Dean approaches the edge of the whirlpool, he'll be pulled down while simultaneously sliding counterclockwise around the ULL- pulling it NW.
how much is 110 knots
that high was suppose to stay very strong to keep dean going due west when did it get weak ?
1069. Oreodog
NOGAPS and GFDN were the first to move Katrina's path from Florida to Louisiana.
1070. Drakoen
Posted By: sporteguy03 at 6:47 PM GMT on August 17, 2007.

Drak,
Can any land interaction with Haiti throw the track off further some models have it dangerously close to the shoreline of Haiti.


That can throw of the strength but not the direction.
The NHC predicts Dean will be Cat 4 hurricane by tonight, 48 hours early.....
1072. GetReal
Just another observation, check out the upper level wind flow on the RGB visible loop, along 75W... It is from the south to the north, from Venezuela across Haiti! I believe that UL flow could have an effect on the track of Dean through the Caribbean.
UKMET had the best Katrina track after Friday night.....
Is it just me and my failing eyesight, or does Dean appear to be moving more North and West than just due West?
It is still VERY early to tell but what are the chances of this thing tracking more to the north and east? I hear all the talk about a ridge that may or may not move blah blah blah....what is it that I am looking for exactly as far as what "stears" a storm?
Thanks for helping the uneducated :)
gfs had the worst katrina track
1076. TXMET
Good point, SavannahS, I guess the ULL operates much the same way as a gravity well caused by a planet acts on a satellite.
DEAN HAS NO steering and no brakes ...............gonna be interesting.....
I suggest yall fill up your cars and get whatever gas you may need b/c the price will skyrocket on monday
I think Jamaica will be the key if it goes south..Mex,Tx. If it goes north central Gulf coast.
1080. TXKiwi
TXDOT has started pre-positioning signs and barricades along I10 ready to set up contra-flow for evacuation of Houston/Galveston
1081. guygee
Click on thumbnail below to see side-by-side comparison of 18/17 12Z GFS initialization for the WATL ULL, compared to 08/16 18Z GFS 18 hour prediction. Yesterday's 18Z GFS run did not close off a low at 300 mb, and overestimated the strength of the low at 500mb and 700 mb, while slightly overestimating the westward movement at 500 mb.

Free Image Hosting at www.ImageShack.us
Drak,cant a very strong storm break through a high if it really wants to?
look at the Visable loop and see that the next forecast point is to have Dean further west on 15.0n yet it seems Dean is already at 15>0n if not borderline
It's very much like that TX. Its funny how the principles of physics can be applied to all sorts of things!
About the ULL talk:
GFS is one of the best at handling general circulation. The below pic shows the ULL forecasted to really move by 12 UTC tomorrow, to the southwest, not the northeast as someone suggested (Thank your lucky stars, FL!, Dean would have recurved behind it).

See this Link to see the time series.

GFS 24 hour 300mb winds
uw

Looking at the upper level winds, it seems as if, the slow moving ULL(slower than modeled is the VERY important point) is acting as a focusing point for the amplification of the Southward bend in the jet stream caused by the cont/polar airmass dropping into the TN valley.

Do any other, specifically, more met trained, eyes see this?
1087. IKE
Posted By: Crawfishman at 1:51 PM CDT on August 17, 2007.
I think Jamaica will be the key if it goes south..Mex,Tx. If it goes north central Gulf coast.


You're probably right. I put a piece of paper up on my computer screen with the top edge of the paper centered from the first tropical forecast point to where Dean is now...and it aims Dean at the southern portions of DR and Haiti.
1088. Drakoen
Posted By: marlinsfan1 at 6:52 PM GMT on August 17, 2007.

Drak,cant a very strong storm break through a high if it really wants to?


I don't think it can break through it lol. I can't put a good dent in it but not break it. Right now the only thing that can pull Dean north is that ULL over the Bahamas.
1089. RyanFSU
The Gulf waters are normal to slightly below normal based upon the 1985-2006 climatology provided by the NOAA AVHRR Pathfinder 0.25 degree data.

SST 2007

We should not forget that Tropical Storm Erin and its blob of convection cooled off the Gulf a wee-bit. Contrast this with 2005: 2005 SST Gulf
It may become a cat 4 at 5pm. Colder cloudtops are continuing increase around the pinhole eye. We know how fast storms with pinhole eyes can intensify. ie... Wilma, Allen, Gilbert
Doens't Haiti have mountains that are notorious for tearing 'canes apart?
1092. Daveg
Posted By: IKE at 6:47 PM GMT on August 17, 2007.

Pull NE? It's drifting west....the one east of Florida.



I see what you are saying, but I think the big high to the west will block it, or not....the high appears to be sliding east. Will the trough along the east coast drag the ULL back east with it? Will it be enough to make a big NW shift? The models already take some or all of that into account, you can tell my the NW turn after 65W.

Man there is a lot in play here. I think I'll stick with the models. Hehe.
1093. bocaman
I'm a South Floridiot living in Pompano Beach Florida. I'm proud to be one. Born and raised in Florida. Drak and Ike, can you see that Dean is already crossing 15 North 3 or 4 degrees of longitude behind the forecast point of it crossing 15 N?
1094. Drakoen
Posted By: IKE at 6:52 PM GMT on August 17, 2007.

Posted By: Crawfishman at 1:51 PM CDT on August 17, 2007.
I think Jamaica will be the key if it goes south..Mex,Tx. If it goes north central Gulf coast.


You're probably right. I put a piece of paper up on my computer screen with the top edge of the paper centered from the first tropical forecast point to where Dean is now...and it aims Dean at the southern portions of DR and Haiti.


thats what i did lol.
Looking at the upper level winds, it seems as if, the slow moving ULL(slower than modeled is the VERY important point) is acting as a focusing point for the amplification of the Southward bend in the jet stream caused by the cont/polar airmass dropping into the TN valley.

Do any other, specifically, more met trained, eyes see this?


if it exntends into the East Gulf then i see it
Gee, it's actually getting a bit gusty in here (San Juan, Puerto Rico). Nothing major, probably less than 20mph but still we've had some winds. Should be an interesting afternoon/evening.
hey guygee, I think were both smelling the same cheese here on the ULL!!!
1098. Drakoen
Again lets not embellish a little motion to the north. If that persist for the next few hours then we can be concerned.
UKMET 12z run is the same as HWRF, CMC and GFS 12z runs. NOGAPS 12z is even further south.

The NHC will probably discuss the divergence between the GFDL and the other models at the 5pm discussion.

Frankly, the GFDL seems to be overplaying the effect that ULL over Florida will have on Dean.

And I do not see Dean moving that much more north of the forecast tropical points on the basis of only one frame.

1100. IKE
Posted By: bocaman at 1:55 PM CDT on August 17, 2007.
I'm a South Floridiot living in Pompano Beach Florida. I'm proud to be one. Born and raised in Florida. Drak and Ike, can you see that Dean is already crossing 15 North 3 or 4 degrees of longitude behind the forecast point of it crossing 15 N?


Yes...the track is more toward the WNW then the NHC has as the most likely track.
1101. TXMET
SavannahS,

If the ULL tracked quickly to the west, such that it were positioned NW of Dean, wouldn't that make Dean more likely to continue west, rather than turning NW (due to the winds on the east side of the ULL blowing south). It seems the current discussion assumes that the ULL will stay east of Dean.
UH OH,someone turned on the PENSACOLA PASS magnet
Thanks W456-

What's your opinion on this developing into a more synoptic scale feature, trof -wise?
---as a believer of the more northernly track within 80w----i will wait and see...
Anything can happen with this storm, in terms of track, over the next several days; If it weakens at all (for whatever reason such as due to some significant interaction with a land mass), then the models will have to re-run and adjust; if it strengthens unexpectedly; same thing.....Everyone in the Caribbean and Gulf needs to keep a close eye on this storm and be prepared in the event that they need to take action....
The storm is still moving more West than anything else. Bear in mind that the rotation/corriolis effect is always trying to turn it to the north. The other conditions surrounding it are not allowing a n/e or n. track as yet.
But it is attempting this turn all the time. A slight variation in the steering influences will result in quick directional changes.
1107. IKE
Posted By: Drakoen at 1:55 PM CDT on August 17, 2007.
Posted By: IKE at 6:52 PM GMT on August 17, 2007.

Posted By: Crawfishman at 1:51 PM CDT on August 17, 2007.
I think Jamaica will be the key if it goes south..Mex,Tx. If it goes north central Gulf coast.


You're probably right. I put a piece of paper up on my computer screen with the top edge of the paper centered from the first tropical forecast point to where Dean is now...and it aims Dean at the southern portions of DR and Haiti.

thats what i did lol.


Then you see where it's headed. LOL.
Posted By: bocaman at 6:55 PM GMT on August 17, 2007.

I'm a South Floridiot living in Pompano Beach Florida. I'm proud to be one. Born and raised in Florida. Drak and Ike, can you see that Dean is already crossing 15 North 3 or 4 degrees of longitude behind the forecast point of it crossing 15 N?


i pointed that out as well its ahead of the forecast points
fla with that ull moving very slowly and dean inching north slowly you are not out of the wood yet . keep watching and the nhc may go further north with the new trac soon .
I bet Ike at NHC they got the rulers out. Have a good day. TGIF
The winds on the east side of the ULL blow north. All low pressure circulations move counterclockwise.
seminolesfan, that makes sense. The jet ahd some pull into the ULL on the west flank causing a southerly downdraft along there, but don't forget the ULH to the west over 'Bama/Mississ helping amplify this effect. But I'm no meteorologist
Looks west to me....Hurricanes never travel in a straight line.
Posted By: SavannahStorm at 6:59 PM GMT on August 17, 2007.

The winds on the east side of the ULL blow north. All low pressure circulations move counterclockwise.


Except in the southern hemisphere, lol
Praying here that the latest GFDL model run is wrong! Not that I wish harm to our amigos to the south, but we have had our quota here on the central Gulf Coast to last us the next 20 years
1116. jrhms08
Don't forget that the NHC is a political and economic entity. I doubt they are going to radically change a forecast track to the north while the markets are still open even if they should adjust it based on the GFDL.
1117. GetReal
bayoubrotha at 6:57 PM GMT on August 17, 2007.
And I do not see Dean moving that much more north of the forecast tropical points on the basis of only one frame.


Where have you been? Dean has been passing to the north of all the previous forecast points since daylight over the E. Caribbean, not just ONE frame!!!
Posted By: quakeman55 at 6:58 PM GMT on August 17, 2007.

Except in the southern hemisphere, lol


Yeah, thats true, lol
GFDL and UKMET are FAR FAR Apart...

GREAT!!! Nobody knows what's gonna happen now!

I believe UKMET will come closer to GFDL in the next run... maybe along the TX/LA border...

I believe Dean has his eyes on Houston/Lake Charles/Baton Rouge...
1120. TXMET
Oops, you're right, Savannah. I was thinking backwards.
Mmmh. Some opinions please. The atmos pressure at San Juan is starting to go down (other than the obvious daily trends) and also the buoy to the north of it. Also some WV signatures are starting to pop up east of the ULL. Would this mean that the high is not building anymore to the west ? Or that it is weakening ?

Link 1: San Juan pressure trend Link

Link 2: Buoy 41043 pressure Link
1122. A4Guy
seminolesfan....why "banned?" Was he posting too much...and too panicky?
Posted By: seminolesfan at 6:58 PM GMT on August 17, 2007.

Thanks W456-

What's your opinion on this developing into a more synoptic scale feature, trof -wise?


If the flow being focus was between two upper level highs then it could of develop into upper trough but what im seeing is the flow lies between the uppper low and the monsoon ridge...BUT...cold air is usually accompanied by low heights i.e. troughs so the upper level circulation over the bahamas could merge into this cold air mass and boom a larger upper low trough over the central gulf....
I'll join the club...Been holding up a post card against my computer screen several times in the last hour or so.....
1125. guygee
Yesterday the WATL ULL even showed up as a trough in the surface analysis.

Since the WATL ULL is retreating more into the upper layers of the atmosphere, its movement will be more affected the upper-level high, strongly influenced by former TS Erin's upper-level circulation that is still obvious in the WV loops.

Also, if the ULL winds are mostly in the upper layers, it would be a source of shear and would not be much of a steering influence should it affect Dean.
1126. IKE
Posted By: weathermanwannabe at 2:03 PM CDT on August 17, 2007.
I'll join the club...Been holding up a post card against my computer screen several times in the last hour or so.....


You see it too. LOL.
Posted By: littlefish at 6:59 PM GMT on August 17, 2007.
seminolesfan, that makes sense. The jet ahd some pull into the ULL on the west flank causing a southerly downdraft along there, but don't forget the ULH to the west over 'Bama/Mississ helping amplify this effect. But I'm no meteorologist


The twin highs(SECONUS & B/A) both being strong was what got my mind turning about the air mass dropping down in between them
1128. bocaman
Good call Crisis, you see that too huh? The NHC is scratching their heads a little bit. It looks like things are getting dicey. By the way, in Broward here, the upper level low has helped lower the dewpoints here into the upper 60's which is unheard of in August. It doesn't feel that bad outside. South
Floridiot for life!
1129. quante
Weather 456 110 Knots is about 126 MPH. You can add 15 to get to MPH, give or take.
Posted By: hurricane23 at 6:58 PM GMT on August 17, 2007.

Looks west to me....Hurricanes never travel in a straight line.


very true but look how it is already inching on 15.0N before the next forecast points which calls for that later on
fla with that ull moving very slowly and dean inching north slowly you are not out of the wood yet . keep watching and the nhc may go further north with the new trac soon .

I have kinda been lassiez-faire about Dean lately; Not really concerned about him now. The ULL is moving quite slow, though. What are the chances now that Dean may affect Florida? I'd say pretty low, 10%, but I want opinions.
I wouldn't be surpised if Dean makes a cat 5 before approaching Hispaniola the way its intensifying right now. There is precidence for cat5's in the ecarib. ie Allen, Ivan, David.
seems like when Dean rapidly deepens, he jogs a bit more to the north than when he's just maintaining/reorganizing. I'd be surprised if this latest apparent northward jog is anything more than that. Probably will force a shift inthe models a bit more to the right, though.
"very true but look how it is already inching on 15.0N before the next forecast points which calls for that later on"

yesterday, bloggers were convinced it would be at 15.0 before it even got to the islands. really, it's actually very close to the forecast points. not a significant deviation at all.
Where have you been? Dean has been passing to the north of all the previous forecast points since daylight over the E. Caribbean, not just ONE frame!!!

Sorry, Dean looks pretty much on track to me. Heading west.
1136. Drakoen
The eye is getting filled again.
dean is a little more north than the forecasted track, so we will have to see if he wobbles any more or not
Yeah Ike...While it may be a temporary motion, we will not really know with this one so I will forget the models for now and keep using the post card every few hours...lol
1139. sngalla
You are right, Boca. The weather here is great today.
1140. KRL
The Latest Western North Atlantic Layer - Mean Wind Analysis

Steering Layer : 700-850 hPa
TC MSLP : 1000-1010 hPa

Link
Its projected to be a Cat 4 tonight, thats two days early......the models are going to have to account for that. Will Dean take a left turn at Jamaica? Doesn't a large storm make that less likely?
1142. IKE
Posted By: rwdobson at 2:08 PM CDT on August 17, 2007.
"very true but look how it is already inching on 15.0N before the next forecast points which calls for that later on"

yesterday, bloggers were convinced it would be at 15.0 before it even got to the islands. really, it's actually very close to the forecast points. not a significant deviation at all.


It's never been significant, but it's always been east or right of wherever the NHC puts their tropical forecast points.

Chad Myers..CNN met...just said that more/several models are now trending toward Dean going north of Jamaica.
1143. Drakoen
KRL why would you use the SFC steering try the upper levels.
what alien track are u looking at.
can u see its been taking a north western move!!!!!!!!!!!
1145. IKE
Posted By: weathermanwannabe at 2:10 PM CDT on August 17, 2007.
Yeah Ike...While it may be a temporary motion, we will not really know with this one so I will forget the models for now and keep using the post card every few hours...lol


LOL.

Post cards come in handy!
Posted By: IKE at 6:52 PM GMT on August 17, 2007. ...................................
You're probably right. I put a piece of paper up on my computer screen with the top edge of the paper centered from the first tropical forecast point to where Dean is now...and it aims Dean at the southern portions of DR and Haiti.


HEY, Who gave away my secret path forecasting technique?? LOL LOL LOL
UKMET, GFS, and GFDL models are in agreement that the storm will pass north of Jamaica......all of the models except GFDL then move the storm almost due west at that point.
1150. bocaman
You know what? Things here in South Florida may get a little weird if this hurricane continues a more northward trend. I know a fact that everyone cannot deny: The upper level low isn't moving, and it was forecasted to pass by us already and is still in the Bahamas.......
actually yesterday, almost the whole day, Dean's actual track was either dead on or even a tick south of the NHC track...though the track has been consistently moving a bit more to the right each time.
1152. hahaguy
boca i hope your wrong lol
1153. Drakoen
1154. Drakoen
Dean has problems keeping his eye open...
right now my post card says dean is alittle north of the fcst track . now lets see if he goes back west to the next fcsat symbol
Dean is well north of were it came though Martinque/St. Lucia
Good afternoon everyone,
Looks like we have a monster on our hands. Any model agreement coming together for days 4 and 5? Increased strength and slower forward speed would definitely diverge forecast track predictions, I don't think any Gulf Coast residents can rest easy yet...
lol dean could end up becoming one of the only cat 4 hurricanes without an eye
1159. Sockets
Drak, Dean is tired thats why...
dean is going to surpise us soon stay tuned
1161. Drakoen
Posted By: Sockets at 7:20 PM GMT on August 17, 2007.

Drak, Dean is tired thats why...


LOL.
xxx knots x 1.136 = xxx mph
Posted By: Sockets at 3:20 PM EDT on August 17, 2007.

Drak, Dean is tired thats why...


rofl
I may be way off, but if you look at the GOES east CONUS water vapor loop there is an upper level low up in Canada driving a trough down through GA, NC, SC. Could this be preventing the UUL east of florida from moving west as expected?
Drak,

Have you looked at the atmos pressures at San Juan and the buoy above it ? Should they be going down that much with Dean approaching ?
1167. guygee
What is striking about the 06Z Ensemble tracks is that the more southern tracks show a stronger recurvature before landfall. Only 3-4 out of 24 show Northern Mexico landfall, and 2-3 show west LA landfall. The rest are strongly clustered along the TX coast. CONUS 06Z ensemble shows landfall near Corpus Christi.
1168. Drakoen
Posted By: BeenThereinMiami at 7:22 PM GMT on August 17, 2007.

Drak,

Have you looked at the atmos pressures at San Juan and the buoy above it ? Should they be going down that much with Dean approaching ?


yea thats normal with hurricane passage.
jrhms08 wrote: Don't forget that the NHC is a political and economic entity. I doubt they are going to radically change a forecast track to the north while the markets are still open even if they should adjust it based on the GFDL.


Believe me, the big guys on Wall St have people watching this storm... they aren't going to rely on NHC when millions & billions are at stake.

Little guys like me are, in turn, watching them. So far, they're apparently not concerned about Dean, but this IS options expiration day... which throws things outta whack.

But I still shorted a coupla reinsurers and went long a coupla onshore drillers.... just for the heckofit.
"2. Goes way way north of track and hits FL"

about as likely as you winning the lottery
1171. TXMET
Bocaman, on the GofMex WV loop, it looks like the ULL is tracking Very Very slowly west. It may not be able to stay ahead of Dean and if it winds up NE of Dean, wouldn't that help keep Dean south?
Check out the band sweeping across Puerto Rico...

Link
1173. bocaman
Drak, you post good images. I've been feeling that too Stormybil, we may be in for a big surprise. That storm on its current 3-4 hour path would be heading straight for the Southern tip of Haiti
Posted By: rwdobson at 7:24 PM GMT on August 17, 2007.

"2. Goes way way north of track and hits FL"

about as likely as you winning the lottery



So... either Texas or N.O gets smoothered... thats what im thinking too...

I might win the lottery...lots of us were wishcasting, now here is the wish
was that a jog or a jump to the north he just took like 15.1 now

im taking number 2 gut felling here .
1176. Crawls
Past history says the GFDL is the most accurate. Hope it's wrong this time!
1177. Drakoen
Posted By: TXMET at 7:25 PM GMT on August 17, 2007.

Bocaman, on the GofMex WV loop, it looks like the ULL is tracking Very Very slowly west. It may not be able to stay ahead of Dean and if it winds up NE of Dean, wouldn't that help keep Dean south?


No. If the ULL and Dean came in contact that would make dean go to North or Northwest.
All models predicted a WNW movement and the storm is exactly doing that.....they differ in the solution after Jamaica, with all but GFDL moving Dean moving almost due west after that, presumably because of diminished strength. But we do know that Dean is getting stronger sooner rather than later, and that may factor into the GFDL track....just some ideas....
The eye is visible in Puerto Rico long range radar. This may be a better way to track it than though satellite imagery.
1180. jrhms08
Wall St and the media aren't looking at models, just the NHC forecast by and large. Right or wrong just a fact of life and since the NHC is a government agency they aren't going to start a justified panic especially after the week the market has had.
looks like a more nnw movement is still in the making------
What are the Chances of dean doing an about face like wilma did?
yeah, that is what i said in my blog. anywhere from mexico (unlikely now) to N O.
1184. C2News
Puerto Rico and some of the Virgin Islands are subsidiaries of the U.S....let's hope they stay safe as some of the bands rotate through.
Looking more and more like a Mexico storm....all models in good agreement except for the GFDL....
1186. guygee
TXMET - If the ULL's circulation is retreating into the upper levels, will it affect steering flow at all? Seems to me that it would be a mostly source of shear if it gets close to Dean and it is only strong at 200mb-500mb.
1187. C2News
What would the ULL near Florida have to do to put Dean on a more northerly or northwesterly track?
"What are the Chances of dean doing an about face like wilma did?"

less than 1%. there would have to be a major cold front coming down to do that, and there isn't.
yeah i see it going thru the yucatan channel, going wnw then nw then n and hitting a saturated texas, considering the ull. no wishcasting, just saying what i think it will do.
one thing to remember with the models that just came out is the fact they were initialized BEFORE the most recent rapid intensification. therefore the models dont take that important in consideration.

a stronger system is more likely than a weaker one to be influenced by an ULL. i see a more NW track to this storm in the very near future.
thanks RWDobson
a sad day

dean kills 3 people

my thoughts are with he family of the people killed

Who knows what the media's doing.... they're a buncha morons... but the Street is watching the models.... believe it.

Though I confess I would have more conviction saying the above if ngas futeures were higher.
Posted By: Drakoen at 7:18 PM GMT on August 17, 2007.

Dean has problems keeping his eye open...


Dean's a Pirate of the Caribbean, he's wearing an eye patch. ;-)
Stormybill...I have your same gut feeling. Have all along. There is something about this storm that just makes me edgy. Even on the space coast of FL I don't feel good about this one.
Just the opposite...strong storms create their own conditions....the stronger the storm..the less impact an ULL would have....this has gotten Mexico written all over it...
1198. Drakoen
Michael chill out with the caps, your getting a little dramatic.
Floridafisherman that is my line of thought......there has to be a reason all the models except GFDL show due west after Jamiaca, and I think its based on the loss of intensity predicted.
It is sad to say one would like Dean to catch a peice of some land mass before the Gulf of Mexico. IE: Yucatan or Western Cuba,(so sorry for people in those areas) BUT, in all honesty, by going straight thru the channel without hitting any land mass presents the potential of a full blown CAT 5 exploding in the Gulf and hitting anywhere from the coast of Tex/Mex Border across the area to the Panhandle of Florida. One just hopes Dean can be downsized in intensity by either of those two areas mentioned. It is a shame there is no place for Dean to go but to hit land somewhere, so the less populated area, obviously the better, for obvious reasons.(evacuations/destruction/economic reasons,health, etc) Be Safe All,and be Prepared. Live in Fla, been thru a few too.
1202. bocaman
CFL Weather thats pretty cool. In Puerto Rico they are about to recieve some good wind gusts out of that. TXMET, it looks to me though that an upper level trough from the low extends down south of Jamiaca with a Southerly wind flow there that would help to push the storm northwards instead of South.
HEY anyone,


How do I save the animation loop of lets say Dean... example at http://www.ssd.noaa.gov/goes/east/watl/loop-avn.html

Im trying to save the html but it does not save the images... whats the trick..?
Yup. The Street will keep a serious eye on Dean. Oil prices already up and analysts are saying Dean is a prime mover. If it continues toward the Gulf there will be a frenzy when the markets open on Monday.
next in the line of fire is jamica lets hope it keeps woobleing north for them for now so wishcasting is ok for today they will be hit bad so dean go north a little more north now
Drak,
Dean likes attention lol
Nice picture Drakoen
eagle, a strong storm is less likely to make a left turn after Jamaica....a stronger storm will continue closer to the NHC official track.
oh boy, I thought my post was too long (RoboDave, yikes)
1210. Drakoen
New blog
is it possible that the trough digging down from the great lakes region could help block the ULL over the bahamas and cause it to move west more slowly? Or will the trough not effect the ULL and move out to sea? You can the the trough on this WV loop. Link
1212. guygee
whirlwind - I don't think you can save a java animation (somebody please correct if I am wrong). You could save the individual images and make your own animated gif.
1213. TX
every time it rains a few inches it's a crawfish fest in my front yard. Maybe the crawfish will be able to tell me if Dean is on its way...Also lately, only the female ruby-throated hummingbird has been in my firebush, while the usually territorial male hasn't been seen in a week around the firebush and feeder..I'll keep the oddities posted in case our flora and fauna give us tell-tale signs of forthcoming ebbing in nature, less flowing of the liquid stuff.
1214. bocaman
TXMET, if you check out the tropical floater image on the NWS Site and you click on the HDW-High box, you can see the upper level winds are from the south there from Jamaica to the Bahamas.
1215. SoTex
I think this is a Texas storm all the way -- probably midcoast. Erin has paved the way leaving a vacuum of low pressure in her trail. But what do I know.

At the very least, we can all be assured that a Cat5 off the Texas/Louisiana border will cause oil prices to break another record and perhaps threaten $100/b.
I remeber Opal having no eye visible at 916 mb because there was cirrus outflow over the eye. And Wilma's eye was almost too small to see at her peak.
1217. sngalla
Java animations can not be saved.
are you in Florida Drakoen? Boynotn Beach Myself
Posted By: TX at 7:38 PM GMT on August 17, 2007.

every time it rains a few inches it's a crawfish fest in my front yard. Maybe the crawfish will be able to tell me if Dean is on its way...Also lately, only the female ruby-throated hummingbird has been in my firebush, while the usually territorial male hasn't been seen in a week around the firebush and feeder..I'll keep the oddities posted in case our flora and fauna give us tell-tale signs of forthcoming ebbing in nature, less flowing of the liquid stuff.


Oh no, we are not going to debate the merits of animals detecting weather 2000 miles away agian, are we? I am all for the idea of animals sensing doom once the pressure begins to drop, by the way, but an alomst full week and 2000 miles away is absurd.
we just got the fist spiral band and on satellite images this thing wasnt even visible.. just looked like high clouds. it was brief but powerful. thank God Dean is well to the south of Puerto Rico and lets hope there is not slight jog to the North that will bring a larger batch of rain then we are expecting.
SoTex I have thought for a while that an Allen (1980) track would be a good guess, and I still believe it. Although we won't know if Dean will thread the Yucatan channel for a while. Heat content off the Texas coast is lower than in the loop, and hopefully Dean will be on the weak side of an eyewall replacement cycle when making landfall. And let's all hope that the inner core of Dean misses the islands! Allen 1980 track
1222. bocaman
Benirica, did that band have some wind gusts? 30-40 mph?
1223. AndyN
Here is what our local meteorologist is saying on his blog:
Models continue to indicate that the upper level ridge to the north of Dean will keep it on a WNW track, bringing landfall somewhere from Mexico up into Texas next week. GFS and NAM do indicate upper low, from 500 mb up to 200 mb, in the NW Gulf early next week. Could this create enough weakness in the ridge to allow the hurricane to turn right? I dont know. But, I think there is still uncertainty with the track beyond Monday.
care to elaborate on 500mb up to 200mb low he is referring to?
1225. TXMET
bocaman,

You're right, but the winds coming across central Cuba are going south. So, maybe it'll wobble north and then back south.
What does Nash Roberts say, or is he dead?
Right now, I am *guessing* that the heat wave ridge will persist a little longer and stronger than models indicate. They always seem to. If that is the case, than a Louisiana landfall won't happen. At least I hope not. Even a landfall by a strong cat 3, say 950 mb/110 kts tracking up 20 miles west of New Orleans would finish off the city I think.
magical-

I agree...a lot of people here get a high off this....and thats where some of the wishcasting is coming from.
im not at my house so i couldnt give you an accurate measure, but a wild guess id say some of the gust couldve got pretty close to 30, maybe around 24. and it was a very thin and random spiral band... i cant imagine what the thicker bands that we may get tonight will bring.
it doesnt take much for mudslides and flooding and winds of only 40 could knock down a few branches making it difficult to get to the remote areas that are prone to mudslides... plus taking out the electricity.
track mark 15,65 C3/H/D
15.2,66
15.5,67
16.1,72 C4/H/D
16.5,75
17.2,77 C5/H/D
17.2,79
18,81 C4/H/D
STOP....
been lurking all day, but not posting.
Looks like we have a very exciting weekend ahead of us. Everyone, just take some deep breaths and get everything ready; you should have all your supplies ready by now anyway if you live in hurricane country, especially along the Gulf Coast and the entire Florida coast line.

This will be very interesting.

Gams
Graphics on the Weather Underground are quick and pretty cool compared to the NHC.
taking our minds off of Dean for a second... its odd that we arent monitoring any other areas. besides dean, the atlantic has just died. and the waves over africa dont seem to impressive. am i wrong? is there something to look at?
Nash Roberts is not dead. His wife just died a few months ago. He retired to be with his ailing wife. I wish he would give us a take on this. Went through many storms with Nash breaking in all day on TV when we were kids.
Oh y'all, new blog.
I'm on a different Computer today and am seriously missing my favorites! Could someone please send me/post the link to Adrian's aka Hurricane23's site?

Thank you!
1239. JAC737
Here in Galveston County -- at Sam's Club this morning -- hurricane supplies flying off the shelves -- pallets of water gone, gas cans gone. Plywood almost gone. Everyone is very cautious and prepared. We went through this with Katrina/Rita so we know the drill. Everyone is predicting, so I will throw my 2 cents in. Based on studying every chart I can get my hands on, I predict that this one will tear up the gulf coast of Texas south to north, like a beach bum. I was right with Katrina and Rita. We will see about this one.
I keep reading about a "new" GFDL model that brings Dean back closer to Galveston\Houston again. I'm only finding older runs that show it closer to the Louisiana border. Does anyone have a link for this revised GFDL run? Thanks!

PS - No way will I ever evacuate from Houston again. We'll ride this one out, thanks.
1241. Aggie92
I live in College Station. It's about 127 miles NW of Galveston and about 130 NNW of Freeport. Given the worst case senario of a Cat 5 storm hitting Freeport, what should I expect this far inland? I know lots of rain, but what about wind?
OK...I respect animal instinct...we just had 10 birds, mockingbirds and blackbirds, in a tree in my front yard where I rarely see more than 1 or 2 birds sit.

What is the chance that ULL in the gulf just north of the yucatan moves faster than what it would take to keep Dean down south of Houston?