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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Quoting Stormchaser2007:
Wow....



Again....heavily heavily weighted by the GFS....50% of those model tracks are all the GFS. Don't post that map as it is misleading....the model consensus is not that weighted towards Texas yet.
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Quoting superweatherman:
why have they not but the 2pm forecast


no watches and warnings are out
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Duhh... just noticed HURLO... I may need him for assistance. LOL
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Quoting GlobalWarming:
someone plz post the latest ecm?


GlobalWarming,

The latest ECMWF model remains virtually unchanged since the last run. Alex is already trekking more to the NW than it is already forecast to go. 456 criticized the COAMPS model for showing a northerly track, and I criticize the ECMWF for showing a Southerly track.
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Quoting Stormchaser2007:
Wow....



are a bit less convinced that this is just a Mexico storm? lol
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why have they not but the 2pm forecast
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I would like to know how rare it is to see a trough like this digging so far South at the end of June?
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.
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I. ATLANTIC REQUIREMENTS
1. TROPICAL STORM ALEX
FLIGHT ONE - TEAL 70
A. 28/0000, 0600Z
B. AFXXX 0401A ALEX
C. 27/2100Z
D. 20.5N 91.0W
E. 27/2300Z TO 28/0600Z
F. SFC TO 10,000 FT

Is this where they expect it to be???? I sure HOPE not!
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I see the northern shift in the models, but am I also seeing a less intense forecast... maybe not even getting to hurricane strength? Wouldn't it have more time to strengthen if it were to go more North?

Now I'm confused.
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thanx Patrap...
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Quoting Stormchaser2007:


Dry air over Texas will keep Alex somewhat limited.


I wouldn't exactly call the bit of dry air over TX a roadblock either. Alex is an enormous system, generating its own moisture swarth 100's of miles wide. And, that will intensify and protect the core back out over water.
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Pat-

Seems like the models are picking up on that early NNW movement like the GFS and CMC have been saying. Each passing runs looks worse and worse for LA and TX and the oil spill regions of LA/MS/AL.
Member Since: July 15, 2006 Posts: 17 Comments: 10156
Quoting bayoubug:
when will the next recon go in...


Scheduled to be at the storm 8:00 PM EDT tonight.
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What are the models picking up that shifts most of them toward the end of their track forecasts to the west? I see the more northern forecast points then there's an abrupt turn to the west with quite a few of them.
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Plan of the Day

000
NOUS42 KNHC 261430
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1030 AM EDT SAT 26 JUNE 2010
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 27/1100Z TO 28/1100Z JUNE 2010
TCPOD NUMBER.....10-026

I. ATLANTIC REQUIREMENTS
1. TROPICAL STORM ALEX
FLIGHT ONE - TEAL 70
A. 28/0000, 0600Z
B. AFXXX 0401A ALEX
C. 27/2100Z
D. 20.5N 91.0W
E. 27/2300Z TO 28/0600Z
F. SFC TO 10,000 FT

FLIGHT TWO - TEAL 71
A. 28/1200, 1800Z
B. AFXXX 0501A ALEX
C. 28/0900Z
D. 22.0N 92.5W
E. 28/1100Z TO 28/1800Z
F. SFC TO 10,000 FT

2. SUCCEEDING DAY OUTLOOK: CONTINUE 6-HRLY FIXES
IF ALEX REMAINS A THREAT.
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Hurlo-man
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Pat, could you send that Hurricane Guy you post periodically over to my house please? What's his name anyway? Thankies...
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It all depends on the strength/orientation of the trough approaching the SE US. Yes, it is possible though. Just have to wait though, we're still 4-5 days out and anything past 72 hours is, well, let's just say less than totally reliable.

Quoting cdr445:
Hello All,

I am rather confused this time; I really do not understand how Alex can move so far north?

Is the TX / LA landfall scenario a supportable outcome?

Thanks!!

Geo %u2013 CDR445 -- (Houston)

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Quoting WinterAnalystwx13:
"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."

I dont see any roadblocks, Shear will be weak due to the Anticyclone, and Water Temperatures are very warm...



Dry air over Texas will keep Alex somewhat limited.
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Hot off the presses so hot I just burned myself

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If it's already shifting to the NW, wouldn't this be earlier than anticipated? And wouldn't this possibly lead to a more right shift on the models?
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Dang pat, everything is shifting north now.
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when will the next recon go in...
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Bada Boom..


18z Early Cycle NHC model tracks
Alex
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)





Dynamic Models (More sophisticated models)




Early Model Wind Forecasts

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Crossing the Yucatan actually helped Alex. The storm had been struggling with consolidating a tight inner core. It doesn't have that problem anymore. The friction with land helped to tighten the storm up. I believe we're gonna see fairly quick intensification rates when he gets back over open water.


Edit: That was weird. I saw then new blog, then it went back to the old one. Server is playing tricks on me.
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Hello All,

I am rather confused this time; I really do not understand how Alex can move so far north?

Is the TX / LA landfall scenario a supportable outcome?

Thanks!!

Geo – CDR445 -- (Houston)

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Cool deal, thanks!
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Quoting LouisianaWoman:
Pat could you post a graphic for the dynamic and early models? Thanks!



Awaiting the new frames now..
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Floater - Visible Loop
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Pat could you post a graphic for the dynamic and early models? Thanks!
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102. xcool
TROPICAL CYCLONE GUIDANCE MESSAGE

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

1855 UTC SUN JUN 27 2010



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



TROPICAL CYCLONE ALEX (AL012010) 20100627 1800 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

100627 1800 100628 0600 100628 1800 100629 0600



LAT LON LAT LON LAT LON LAT LON

BAMS 18.9N 90.7W 19.9N 91.9W 21.0N 92.6W 21.4N 93.1W

BAMD 18.9N 90.7W 19.6N 91.9W 20.1N 92.8W 20.3N 93.6W

BAMM 18.9N 90.7W 19.7N 92.0W 20.4N 92.8W 20.8N 93.3W

LBAR 18.9N 90.7W 20.1N 92.0W 21.2N 93.5W 22.5N 95.0W

SHIP 30KTS 33KTS 40KTS 48KTS

DSHP 30KTS 36KTS 43KTS 51KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

100629 1800 100630 1800 100701 1800 100702 1800



LAT LON LAT LON LAT LON LAT LON

BAMS 22.0N 93.6W 23.2N 94.2W 24.9N 94.7W 27.2N 95.8W

BAMD 20.5N 94.5W 21.0N 96.5W 21.1N 98.4W 21.3N 100.5W

BAMM 21.3N 94.0W 22.0N 95.1W 22.7N 95.9W 24.6N 96.1W

LBAR 23.9N 96.6W 26.8N 98.8W 29.5N 99.3W 32.2N 97.7W

SHIP 59KTS 78KTS 85KTS 84KTS

DSHP 62KTS 81KTS 61KTS 30KTS



...INITIAL CONDITIONS...

LATCUR = 18.9N LONCUR = 90.7W DIRCUR = 300DEG SPDCUR = 9KT

LATM12 = 18.0N LONM12 = 89.0W DIRM12 = 300DEG SPDM12 = 11KT

LATM24 = 17.2N LONM24 = 87.3W

WNDCUR = 30KT RMAXWD = 75NM WNDM12 = 35KT

CENPRS = 999MB OUTPRS = 1007MB OUTRAD = 240NM SDEPTH = D

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

NNNN
Member Since: September 26, 2009 Posts: 2 Comments: 15603
Quoting Jeff9641:


Hey Pat what's the mode in the NOLA area?


Oil vey ..

Were all watching closely..

Dr. Masters been on WWL Radio all week here and the Local Mets are on it.
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Like many of us in the Northern Gulf coast, I am simply devastated with a possible track into Louisiana because it would mean oil waters coming ashore into the vicinity of the Pensacola-FWB-Destin areas. Also, unlike the rest of Florida, our whether in the extreme Northwest Panhandle region aligns more towards NOLA, Mississippi, and Alabama. With the large size of that storm, any tracking towards the Western edge of the NOLA area could possibly send Tropical Storm force winds here. I like everyone is hoping that this trough does not dig any further allowing the storm to go in South of the United States.
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Quoting hurricanejunky:


Looking at NHC rainbow loop it looks like it's moving west or barely north of west. Maybe it's the rainbow loop that's deceiving me...


Don't look at infrared loops for motion. Visible is going to be better to use.
Member Since: July 15, 2006 Posts: 17 Comments: 10156
I doubt Alex will hit the US, but I do see it strengthening to a minimal Category 2 before landfall.

Quite a way to start off the season.
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There is so much traffic near the oil spill,I would imagine that a mass evacuation will result in complete confusion.
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Quoting tropicfreak:


Everyone on this blog is posting new projected paths on alex, the models are catching on to this as well.


Oh I thought you were talking about the 12z CMC, which pretty much is a LA landfall.
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Thanks for the update, Dr M.

Follow the yellow brick road...
(in my best munchkin voice)
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Quoting CybrTeddy:
TD Alex is down to 999 mb.. its also about to emerge off the coast (I think it already has)


Its strengthening no question about that.
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12z UKMET, still Mexico but im not sure im buying it anymore.

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Station 42001 (LLNR 1400) - MID GULF 180 nm South of Southwest Pass, LA

5-day plot - Wind Direction Wind Direction (WDIR): SE ( 140 deg true )

5-day plot - Wind Speed Wind Speed (WSPD): 15.5 kts

5-day plot - Wind Gust Wind Gust (GST): 17.5 kts

5-day plot - Wave Height Wave Height (WVHT): 4.3 ft

5-day plot - Dominant Wave Period Dominant Wave Period (DPD): 7 sec

5-day plot - Average Period Average Period (APD): 4.9 sec

5-day plot - Atmospheric Pressure
Atmospheric Pressure (PRES): 29.87 in

5-day plot - Pressure Tendency Pressure Tendency (PTDY): -0.01 in ( Falling )

5-day plot - Air Temperature Air Temperature (ATMP): 84.2 °F

5-day plot - Water Temperature Water Temperature (WTMP): 85.6 °F

5-day plot - Dew Point Dew Point (DEWP): 75.9 °F

5-day plot - Heat Index Heat Index (HEAT): 93.2 °F
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About JeffMasters

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