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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Alex's lowest minimum pressure is 991.0mb.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
2836. Levi32
991.0mb.


Atlantic USAF High-Density Observations


000
URNT15 KNHC 280303
AF304 0401A ALEX HDOB 39 20100628
025400 1914N 09115W 9249 00607 9911 +228 +186 360006 007 020 001 00
025430 1914N 09113W 9248 00608 9910 +226 +189 050000 004 022 000 00
025500 1914N 09111W 9252 00602 9910 +224 +192 184008 010 024 003 00
025530 1913N 09110W 9249 00608 9914 +221 +193 191009 010 999 999 03
025600 1913N 09110W 9249 00608 9915 +221 +194 224008 009 999 999 03
025630 1911N 09111W 9247 00611 9914 +221 +195 220009 009 999 999 03
025700 1913N 09112W 9253 00603 9910 +226 +195 204004 007 022 002 00
025730 1914N 09113W 9249 00605 9910 +225 +196 043004 007 024 001 00
025800 1915N 09114W 9249 00608 9911 +228 +197 047008 009 021 000 00
025830 1916N 09116W 9248 00610 9912 +225 +197 051011 013 020 000 00
025900 1917N 09117W 9250 00610 9915 +228 +198 040020 022 025 000 00
025930 1918N 09118W 9248 00614 9918 +223 +198 043026 027 030 003 00
030000 1919N 09119W 9246 00619 9925 +215 +198 056028 030 034 001 00
030030 1920N 09120W 9246 00623 9931 +210 +197 067034 035 034 000 00
030100 1922N 09122W 9251 00624 9937 +208 +194 071036 037 034 001 00
030130 1923N 09123W 9251 00628 9943 +204 +191 069037 039 035 001 00
030200 1924N 09124W 9248 00636 9948 +205 +186 067036 037 035 000 00
030230 1925N 09125W 9248 00638 9950 +210 +182 068034 034 031 002 00
030300 1926N 09127W 9252 00638 9954 +206 +179 068033 034 031 000 00
030330 1928N 09128W 9250 00641 9956 +208 +177 070030 031 031 000 00
$$
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The stronger it gets ... the further north it gets
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Hey IKE buddy! How are you?

Any thoughts on Alex? I don't have a clue lol!
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The hurricane hunters are still in TS Alex?
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2830. Seastep
Quoting scott39:
Is the ECMWF the King of all models?


From Doc's post.

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2829. IKE
Quoting F4PHANTOM:
It's been doing that since yesterday.


The NAM isn't alone....
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Quoting Patrap:


The steering may go NILL in the Western to West Central GOM after 30 hours.

A dilemma one could say.

Oil vey..!

What are your thoughts on Alex performing an Opal type maneuver? With the current data is it a possibility or probably not?
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What error?
Member Since: October 25, 2005 Posts: 19 Comments: 22305
2825. scott39
It almost looks like on the Sat that Alex backed up a little and went SW. IMO
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2824. Levi32
Quoting Hardcoreweather2010:
GFS you are charged with the impersonation of the XTRAP model



Oh epic fail...it got fixed.
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Quoting Baltimorebirds:
Luckly not many people died in charley.

Oh yeah that's definately true, I guess it's small size & speed kept that from happening. Plus that area is pretty rural unlike New Orleans.
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2822. xcool
IKE .I' M NOT SO confidence BY NHC .if you know why.thanks.
Member Since: September 26, 2009 Posts: 2 Comments: 15684
GFS you are charged with the impersonation of the XTRAP model



They did have GFS with a straight line into LA but I didn't save the image in time
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2819. IKE
Quoting xcool:
I' M NOT SO confidence BY NHC .


After hurricane katrina.IMO


Would you say that if the 5 day track was right over you?
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Quoting Baltimorebirds:
What does refresh do??


Uh, it refreshes the page. :)
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Quoting jaevortex:


-blinks- Darn it Mrstorm, that's a messed up error there.


Hope people understand its an error, and aren't heading for the hills.
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2804 I've got to get some rest that storm looks like it's headed se I hope it doesn't do a loop into fl.
Member Since: August 18, 2008 Posts: 0 Comments: 3113
looking at west Atlantic wv and it just looks crazy out there. can anybody elaborate on all the activity i see in this wv loop? also can you give explanation of what if any effect the activity out there has on Alex? thanks in advance:) i would really appreciate everyone's input.
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Anyone....

Why is the 5-day forcast STILL not more in-line with the model consensus?? ..

There are thousands of miles worth of difference between the forcast and model medians...
the 5-day is south and the models are north...
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Quoting MrstormX:
Whoa thats a major error!



-blinks- Darn it Mrstorm, that's a messed up error there.
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Quoting LSU791:
I can still remember Katrina. All the models and all the exprts were all over a Florida landfall. They continually dicounted an outliers that dared to defy the majority. Then suddenly we in LA had 48 hours to prepare. Never discount the "NERD" for he knows more that you think. In reading the NHC statement one phrase popped out to me " An UNUSUALLY DEEP longwave trough." Kind of make you say hmmmm...

That "unusually strong upper level trough over the NE US is going to make for a VERY interesting next 3 or 4 days. IF that trough weakens the upper level ridge over the northern GOM, there is going to be a shift further northward!!
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2809. xcool
I' M NOT SO confidence BY NHC .


After hurricane katrina.IMO
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting atmoaggie:

Hmmm, now RecordSeason and WU are wishing right into here...not at all cool.


Looks WU is the biggest wishcaster of all.
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Thanks
Quoting MiamiHurricanes09:
Not much. The trough might advance a bit more but not much change in track overall.


GTK - thanks!
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Quoting jlp09550:
Stationary. Actually looks to be moving a bit southward.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Member Since: Posts: Comments:
Quoting MrstormX:
Whoa thats a major error!


Hmmm, now RecordSeason and WU are wishing right into here...not at all cool.
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Looks like there is a sufficient amount of ridging N&W of Alex to keep it wondering ever so slowly in the BOC. I'm not sure there will be enough time to recover to the north to be affected by the trough. Will not even begin to think out solutions past 48 hrs.
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Quoting AustinTXWeather:


If it moves slower than anticipated, what can that mean for the track it takes?
Not much. The trough might advance a bit more but not much change in track overall.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
2799. Patrap
Quoting IKE:


It could...but it has it go NNW...then NW...then W...then SW...then ESE...

And I'm not making that up...lol.




Doubt ALEX is gonna follow any script.


Itsa in a Bad location and the Motion vector direction the next 24 will determine a LOT downstream
Member Since: July 3, 2005 Posts: 426 Comments: 128626
Quoting Levi32:


Doubtful....it's not stacking with the ULL.
Quoting Baltimorebirds:
Oh yeah the track shifted suddenly and caught some people off guard.

You think that's something eh Charley paid a surprise visit to the Port Charlotte area, & they only had a few hours to prepare, not even.
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Anyone....

Why is the 5-day forcast STILL not more in-line with the model consensus?? ..

There are thousands of miles worth of differnce between the forcast and model medians...
Member Since: Posts: Comments:
.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
2795. Levi32
Just starting to pass through the very center with 991.4mb. May be a bit lower yet.

000
URNT15 KNHC 280253
AF304 0401A ALEX HDOB 38 20100628
024400 1934N 09139W 9253 00657 9976 +207 +178 052028 028 032 002 00
024430 1933N 09138W 9249 00659 9975 +210 +179 053028 029 032 000 00
024500 1932N 09137W 9248 00659 9973 +208 +179 055028 029 032 001 00
024530 1931N 09136W 9253 00651 9971 +210 +180 054030 032 033 000 00
024600 1930N 09134W 9250 00653 9968 +212 +181 054030 030 034 000 00
024630 1929N 09133W 9248 00655 9967 +210 +181 053031 032 035 000 00
024700 1927N 09132W 9248 00651 9965 +206 +181 055033 034 034 000 00
024730 1926N 09131W 9249 00649 9963 +205 +179 060033 034 033 002 00
024800 1925N 09130W 9250 00646 9961 +207 +177 057030 032 033 002 00
024830 1924N 09129W 9252 00644 9960 +210 +174 055028 028 034 000 00
024900 1923N 09128W 9248 00645 9957 +210 +173 056029 030 032 000 00
024930 1922N 09126W 9248 00642 9954 +210 +173 053029 030 033 001 00
025000 1921N 09125W 9246 00641 9951 +210 +172 053029 030 032 001 00
025030 1920N 09124W 9244 00639 9947 +210 +172 052028 028 033 000 00
025100 1919N 09123W 9250 00626 9937 +211 +172 045026 026 032 001 00
025130 1918N 09122W 9252 00619 9932 +214 +172 033025 026 032 000 00
025200 1917N 09121W 9249 00619 9927 +215 +174 021024 025 031 001 00
025230 1915N 09119W 9249 00615 9921 +224 +177 012023 024 025 001 03
025300 1915N 09118W 9248 00613 9916 +231 +179 006017 018 023 000 03
025330 1914N 09116W 9250 00608 9914 +225 +183 002009 011 020 000 00
$$
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Good night all as Jack Horkenhiemer would say keep looking east.
Member Since: August 18, 2008 Posts: 0 Comments: 3113
Whoa thats a major error!

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2792. IKE
Quoting Patrap:


The steering may go NILL in the Western to West Central GOM after 30 hours.

A dilemma one could say.

Oil vey..!



It could...but it has it go NNW...then NW...then W...then SW...then ESE...

And I'm not making that up...lol.
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getting closer!!!place bets on movement NOW!!!!:



I guess NNW...
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Quoting MiamiHurricanes09:
Got ya'.


If it moves slower than anticipated, what can that mean for the track it takes?
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Quoting Patrap:
00z Early Cycle NHC model tracks
Alex
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)





Dynamic Models (More sophisticated models)



Early Model Wind Forecasts

A voice of Reason, Thanks Pat. I will add though, that I would like to see if any change occurs in the models in the next 12-24 hours
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2788. xcool
TX TO LA KEEP EYE ON BAD BOY.
Member Since: September 26, 2009 Posts: 2 Comments: 15684

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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.

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