Alex may head north to Texas or Louisiana

By: Dr. Jeff Masters , 6:36 PM GMT on June 27, 2010

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Tropical Depression Alex has held together fairly well during its passage over Mexico's Yucatan Peninsula, and stands poised to re-intensify back into a tropical storm once it emerges from the coast tonight. Alex brought heavy rains to northern Honduras, Mexico's Yucatan Peninsula, and Belize over the weekend. It was not a good beach day in Cozumel yesterday, as 9.25" of rain fell. Cancun received 2.05" over the weekend, and Belize City received 4.57". Satellite loops show that Alex's heavy thunderstorms are mostly gone near the center, though there are some impressive bands of precipitation well away from the center. There is an upper-level high pressure system a few hundred miles west of Alex, and the clockwise flow air around this high is bringing upper-level winds out of the northwest of about 5 knots over the storm, contributing to the 5 knots of wind shear observed in this afternoon's wind shear analysis from the University of Wisconsin's CIMSS group. Sea Surface Temperatures are very warm, 29 - 30°C, and dry air is currently not a problem for Alex.


Figure 1. Afternoon satellite image of Alex.

Forecast for Alex: which model should you trust?
While the track forecast for Alex today through Monday is fairly well-assured, the longer range forecast has become highly uncertain. An increasing number of our reliable models are now indicating Alex may take a more northerly track beginning on Tuesday, with possible landfall on the Texas coast near Galveston on Friday (according to the 8am run of the GFS model) or into western Louisiana on Wednesday (the 8am run of the Canadian model.) The key question remains how Alex will react to the trough of low pressure expected to swing down over the Eastern U.S. on Monday and Tuesday. Most of the models were predicting that the trough would not be strong enough to swing Alex to the north, and several of them continue to predict this. The 8am runs of the NOGAPS and ECMWF models, for example, take Alex into the Gulf coast of Mexico 150 miles south of Texas, on Wednesday. The GFDL and HWRF models split the difference, with the GFDL predicting a Thursday landfall in southern Texas near Brownsville, and the HWRF predicting a Thursday landfall near Corpus Christi. Morris Bender of the GFDL group has just provided me the track forecast from an improved experimental version of the GFDL that shows landfall between Corpus Christi and Galveston. So which model should you trust? Last year, the best performing models at the 3 - 4 day forecast range were the GFS and the Canadian, and these are the models that are currently calling for the more northerly track towards the upper Texas coast and Louisiana. Residents of those areas should review their hurricane preparedness plans and anticipate that Alex could make landfall as early as Wednesday in their vicinity. Residents of the Mexican coast south of Brownsville should make similar plans, as Alex could just as easily hit there.

Re-intensification of Alex is likely once the center of Alex moves offshore, though this will initially be slow due to the current disorganized state of the storm and the relatively low total ocean heat content in the 100-mile-wide stretch of water on the west side of the Yucatan Peninsula. Once Alex moves more than 100 miles from the Yucatan, total heat content of the ocean increases substantially, and Alex will have the opportunity to intensify significantly. A longer time spent over water will give Alex more of a chance to strengthen, and it is possible Alex could intensify into a major hurricane if landfall is delayed until Thursday or Friday. However, Alex's intensification may be limited the farther north it gets, as water vapor satellite images show plenty of dry air over Texas that might interfere with development. Wind shear might also be an issue for Alex if it pushes far enough north, and a slow-moving storm tends to pull up cold water from the depths, limiting intensification. In short, Alex has the potential to intensify into a major hurricane, but there are plenty of roadblocks that make this only a 10% probability in my estimation.


Figure 2. Skill of computer model forecasts for Atlantic named storms during 2009. OFCL=Official NHC forecast; GFS=Global Forecast System model; GFDL=Geophysical Fluid Dynamic Laboratory model; HWRF=Hurricane Weather Research Forecasting model; NOGAPS=Navy Operational Global Prediction System model; UKMET+United Kingdom Met Office model; ECMWF=European Center for Medium Range Weather Forecasting model; CMC=Canadian GEM model; TVCN=one of the consensus models that lends together all (or most) of the above models; BAMM=Beta and Advection Model (Medium Layer.) Image credit: National Hurricane Center 2009 verification report.

Elsewhere in the tropics
A tropical wave (Invest 94L) a few hundred miles north of the northernmost Lesser Antilles Islands has been pretty much torn apart, and is no longer a threat to develop.

Next post
Wunderground's severe weather expert Dr. Rob Carver will likely be posting an update on Alex late tonight. My next update will be Monday by 10am EDT.

Jeff Masters

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BTW - in terms of that trough pushing into the southeast US, well, it went over us yesterday and let me tell you it was pretty damn strong! If there's any question about the thing being able to pitch a hurricane north, query no more! We had lightning, hail, tornadoes, the works - quite the lightshow!
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Operational GFS 114 hours





Parallel GFS 102 hours




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Quoting Levi32:
Reorganization of Alex will be slow and gradual. It could take him a full 24-36 hours before he gets back to the intensity he was at during landfall in Belize.


Alex is coming off at the end of the day which gives it an advantage versus coming off in mid morning and having the heat of the day to contend with. In addition, the core pressure is fairly well established now which should shorten the time to reorganise as balanced against the TCHP deficit compared to the W Caribbean.
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i wounder if WunderBlogAdmin still works here i have not here from him for some time
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Quoting taco2me61:
**Breaking News*** BP is Evacuating some of its crews from the GOM....

Taco :o(


The TS won't even be near that area! (I bet they just don't want to work so Tony Hayward can Yacht. >:(
Member Since: April 1, 2010 Posts: 9 Comments: 2699
1031. CCkid00
Quoting RecordSeason:
I may have to log off shortly.


Based on infrared, there is about to be a ridiculous amount of shear and bad weather across the northern gulf coast over the next several hours as these air masses collide. Watch severe thunderstorms and tornadoes people.

Alex may even make a hard right pretty soon also. The front is digging in deeper than I expected.

where do u live on the northern gulf coast?
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1030. MZV
Agree kmanislander. This is one of the best structured "tropical depressions" I've seen. Very well organized banding features in all quadrants. Some dry air to work off in the NW but this system is primed to take off.
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My recap of the past few days:
Conditions change. Forecast has been remarkably consistent though. The initially forecast I saw a few days ago was roughly towards central texas. Then it shifted south towards mexico. The feeling then was that the trough wasn't strong enough to pull alex north. Conditions changed and now they're saying that the trough might be strong enough to pull alex north. Now we're back a possible texas landfall. I think the forecast has been accurate because mexico and texas have been in the cone of doom the entire time.

It's interesting how people have their own opinion about where it's going and people can get frustrated with anyone who disagrees. You see this everywhere in forums about every topic imaginable. It's not just confined here. I think I am a contrarian when arguments are my subject, but depends on my mood.
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Hello everyone, mostly a lurker for the past 3 years or so, but finally decided to come out of lurkdom. I live right next to Orca in Victoria and have always been fascinated by the weather, even made a tornado simulator when I was younger too. The storm that really brought me here constantly is Omar hence my picture of that monster. Anyways I'll try to post thoughtful thoughts when possible and leave all the rest to the experts out there.

In the recon flight if they already found 30 kt winds in one of the feeder bands, I think Alex has to be a tropical storm right now right?
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**Breaking News*** BP is Evacuating some of its crews from the GOM....

Taco :o(
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Some are saying the 18z GFS is trending west which would be good for me but this one shows a TX/LA landfall is this one old?

Link
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I have been on WU since pre-Katrina and when storms slow down it usually means a change in direction. This is sign that the high pressure ridge is either weakening or moving away and we get less Wesward motion.
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Quoting StormW:


I don't know!


Lol you had be worried
Member Since: May 27, 2009 Posts: 0 Comments: 4436
Quoting Stormchaser2007:


Nothings set in stone...



I know, but it's always a possibility. It's better to be safe than sorry IMO.
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1019. Levi32
Reorganization of Alex will be slow and gradual. It could take him a full 24-36 hours before he gets back to the intensity he was at during landfall in Belize.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
.in before the blog panics!


i think its too late for that
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1017. xcool
Member Since: September 26, 2009 Posts: 2 Comments: 15620
Here is what our local met said here in Lake Charles :

Another hot and humid day is expected with highs topping out in the upper 90's. Clouds will be mixed with sunshine today and a few pop up showers and thunderstorms could be around this afternoon. Rain chances will increase through this upcoming week with a late season front coming through Tuesday and Wednesday. That front will help to steer Alex southward and keep the tropical system away from the Louisiana coastline. This week be hot and humid with hit and miss showers around in the afternoons. For the latest on Alex head over to the hurricane page. Have a nice Sunday!
Member Since: June 16, 2008 Posts: 0 Comments: 507
Storm....where do you think Alex will go?
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wasn't there some model that predicted that Alex would bifurcate into two storms, one headed toward Fl and the other to Texas or Mexico? Well, that burst to the north of the COC is looking less like a rain band and more of a storm in and of itself - no?
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Quoting StormW:


I don't know!

LOL!
Member Since: June 10, 2010 Posts: 6 Comments: 578
1012. ATL
Quoting Tazmanian:


YAY ITS OFF LAND NOW

Weakening flag on...in before the blog panics!
Alex is not wasting any time rebuilding the core. Cold cloud tops starting to show in the center and the band from the N expanding in coverage and intensity.

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Quoting jlp09550:


Yeah.. looks like we're going to get the east side.. gah!


Nothings set in stone...

Member Since: June 9, 2007 Posts: 4 Comments: 15776
Thanks again all!!
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Quoting Stormchaser2007:
18z GFS
FULL IMAGE


Yeah.. looks like we're going to get the east side.. gah!
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Quoting Thundercloud01221991:
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 27 JUN 2010 Time : 211500 UTC
Lat : 19:13:23 N Lon : 90:55:16 W


CI# /Pressure/ Vmax
3.2 / 999.1mb/ 49.0kt


Final T# Adj T# Raw T#
2.8 2.6 2.6

Latitude bias adjustment to MSLP : +1.5mb

Center Temp : +5.1C Cloud Region Temp : -25.6C

Scene Type : CURVED BAND with 0.38 ARC in MD GRAY
Maximum CURVED BAND with 0.56 ARC in MD GRAY
at Lat: 18:13:11 N Lon: 89:55:11 W

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : OFF



intensity indicates a TS still


YAY ITS OFF LAND NOW
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Quoting TarheelNMiami:


Is Alex beginning to wrap storms around an eye?
Eye? Alex currently is classified as a tropical depression. The reason you see that is because there is a void of convection over the COC. I'm sure a CDO will develop sometime in the next 72 hours.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Convection increasing around the center

Member Since: June 9, 2007 Posts: 4 Comments: 15776
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 27 JUN 2010 Time : 211500 UTC
Lat : 19:13:23 N Lon : 90:55:16 W


CI# /Pressure/ Vmax
3.2 / 999.1mb/ 49.0kt


Final T# Adj T# Raw T#
2.8 2.6 2.6

Latitude bias adjustment to MSLP : +1.5mb

Center Temp : +5.1C Cloud Region Temp : -25.6C

Scene Type : CURVED BAND with 0.38 ARC in MD GRAY
Maximum CURVED BAND with 0.56 ARC in MD GRAY
at Lat: 18:13:11 N Lon: 89:55:11 W

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : OFF



intensity indicates a TS still
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Quoting TarheelNMiami:


Is Alex beginning to wrap storms around an eye?


No.
Member Since: April 1, 2010 Posts: 9 Comments: 2699
is this the 18Z GFS

Link
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lol...Patrap must be a comedian?
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Is Alex beginning to wrap storms around an eye?
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What happend to StormW ?
Member Since: May 27, 2009 Posts: 0 Comments: 4436
TexasHurricane read post 950
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992. MZV
That flare of convection to the North is becoming an obvious arc now.
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Quoting connie1976:
I thought that Alex wasn't LA, but now I read that some say he might? why don't any of the models say that? I'm confused...
It is unlikely that he will be a Louisiana event at the moment, but it definitely remains a possibility.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Later ya'll. I'll be back after 8 p.m. EDT to see what's poppin'....

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Quoting MiamiHurricanes09:
That tells you how much uncertainty the NHC has right now.


They normally do that.
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Quoting connie1976:
I thought that Alex wasn't LA, but now I read that some say he might? why don't any of the models say that? I'm confused...


One word answer. Wishcasters.

Member Since: April 1, 2010 Posts: 9 Comments: 2699

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