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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Just did a blog on Alex.
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Looks as if Alex is near the coast, and in the last couple hours has done an amazing job feeding from the warm Gulf waters! I must also say, The Yucatan did little to interfere with a very vigorous circulation!

Seems little doubt that Alex will be the first Hurricane of the Atlantic Hurricane season!

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1986. MZV
Probably the last decent visible we'll get until tomorrow:

Member Since: July 3, 2008 Posts: 0 Comments: 227
Move over NHC the JTWC will be following Typhoon Alex for now on.
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Wow Patrap, Statistical models = consensus, Dynamic models = throw a dart lol
Member Since: October 16, 2008 Posts: 0 Comments: 544
se. la. here, and i'm always interested. wish i could chop these 3 huge trees down that are in front my house. we got a little wind and rain here today and it made me realize how dangerous these trees are.
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Watching those satellite images of how large Alex is and how those bands are moving towards us here in SELA, a potential Texas landfall would mean what for us, BP-wise???
Member Since: August 24, 2008 Posts: 2 Comments: 221
Quoting WildWillyFL:
Is the track political? I been watching this site for a while. Over the last few days this storm has been late to classify and consensus track has never really been Mexico (for a stronger storm).

I will be the first one to admit steering currents and modeling is a crazy science, but when most say north, and NHC says south, it makes you wonder? Heck, very few of the experts here expect a landfall south of Texas (most models don't).
I recall one moment where a hurricane was near florida and a bunch of people in here were disagreeing with the NHC. NHC was right. That moment taught me that the NHC is a more trustworthy source than anonymous people here. Of course, you shouldn't have to work so hard to know that!
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Recon going to check out the COC, again. Pressures decreasing, again. Lol.

000
URNT15 KNHC 280043
AF304 0401A ALEX HDOB 25 20100628
003400 1943N 09229W 9244 00688 0002 +211 +172 027028 028 031 001 00
003430 1941N 09229W 9246 00686 0002 +212 +172 028027 028 031 000 00
003500 1939N 09229W 9245 00689 0001 +214 +172 023026 027 031 000 00
003530 1938N 09229W 9250 00682 0001 +213 +171 022027 028 031 000 00
003600 1936N 09229W 9247 00684 0001 +213 +171 020027 028 032 000 00
003630 1934N 09229W 9248 00684 0000 +213 +171 017027 028 032 000 00
003700 1932N 09229W 9249 00682 9999 +215 +171 015028 028 032 000 00
003730 1930N 09229W 9251 00679 9998 +217 +172 013028 028 031 002 00
003800 1929N 09229W 9248 00683 9996 +220 +172 013028 028 031 000 00
003830 1927N 09229W 9251 00678 9996 +218 +173 009028 029 034 005 00
003900 1925N 09229W 9248 00681 9995 +220 +173 008029 029 033 001 00
003930 1923N 09229W 9246 00681 9994 +224 +172 009029 029 032 001 00
004000 1921N 09229W 9250 00678 9995 +218 +172 006030 030 031 003 00
004030 1919N 09229W 9248 00680 9994 +215 +173 005029 029 032 001 00
004100 1917N 09229W 9250 00678 9994 +218 +173 006030 030 032 000 00
004130 1916N 09229W 9248 00680 9994 +219 +174 005028 029 032 000 03
004200 1914N 09229W 9249 00678 9994 +219 +174 006029 030 032 001 00
004230 1912N 09229W 9247 00680 9994 +218 +175 002030 030 032 001 00
004300 1910N 09229W 9249 00679 9994 +217 +175 001031 031 031 001 00
004330 1908N 09229W 9247 00681 9994 +215 +176 360032 032 031 001 00
$$
;
Member Since: September 2, 2009 Posts: 130 Comments: 21091
look like Alex is finally back over water,the center anyway.
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1977. CCkid00
Quoting Joanie38:


OMG!!! YOU are SO like me!! Welcome to the Weatherunderground!!!

thanks Joannie! as long as there is a system out there, i'll be IN here! :-)
Member Since: August 22, 2008 Posts: 0 Comments: 305
1976. Levi32
Quoting hydrus:
Did you read post#1626 Levi?


I did. I think it's unlikely they will upgrade Alex to a hurricane over the Yucatan because the winds were almost certainly not hurricane force at the surface due to land friction, even though the system had the pressure and structure to support those winds. Had it done that over water, the winds would likely have been hurricane force.
Member Since: November 24, 2005 Posts: 635 Comments: 26564
Quoting Acemmett90:
taz
Time: 00:43:30Z
Coordinates: 19.1333N 92.4833W
Acft. Static Air Press: 924.7 mb (~ 27.31 inHg)
Acft. Geopotential Hgt: 681 meters (~ 2,234 feet)
Extrap. Sfc. Press: 999.4 mb (~ 29.51 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 360° at 32 knots (From the N at ~ 36.8 mph)
Air Temp: 21.5°C (~ 70.7°F)
Dew Pt: 17.6°C (~ 63.7°F)
Peak (10s) Flt. Lvl. Wind: 32 knots (~ 36.8 mph)
SFMR Peak (10s) Sfc. Wind: 31 knots (~ 35.6 mph)
SFMR Rain Rate: 1 mm/hr (~ 0.04 in/hr)
(*) Denotes suspect data


ok
Member Since: May 21, 2006 Posts: 5091 Comments: 114776
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should get an updated message from nhc saying back at ts strenth
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Quoting VAbeachhurricanes:


0Z CMC now goes right into the heart of LA


I can't find the 00 cmc. Didn't see it out. Can you post that link? Thnks
Member Since: August 26, 2006 Posts: 0 Comments: 1547
1969. 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

Member Since: July 3, 2005 Posts: 421 Comments: 127663
Quoting Clearwater1:


Do you really think the NHC would post erroneous report for political reasons? That's not going to happen. To many people in involved to keep in under wraps. And I don't think they would do it anyway.
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any thing new with the HH
Member Since: May 21, 2006 Posts: 5091 Comments: 114776
Looks like I better get my go bag in order. A bit early for us FEMA folks to deal with a hurricane but it is starting to look more like maybe Texas with this one. Living in SW Texas I'd like to get some rain from this system but I sure don't want to see another Texas coast strike. I especially don't want this thing to head further east. Texas is a better choice than Louisiana. Those folks don't need any more misery!
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So what we are seeing model-wise is more of a concensus for landfall between Brownsville and Corpus?

If so, this is more believable.
Member Since: October 25, 2005 Posts: 19 Comments: 21584
1964. hydrus
Quoting Skyepony:


In the last 24 hrs Darby has removed more WV from the air in that general area & dumped it as rain than Alex..
Little Darby beating out Typhoon Alex? lol
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Quoting victoriahurricane:


That's just a ULL (Upper Level Low)
It's actually a tropical wave interacting with an upper level low, but you can call them the same thing.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Quoting MrstormX:


Masters is a beast

LMAO...Word.
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1960. Patrap


Member Since: July 3, 2005 Posts: 421 Comments: 127663
*TEXAS RESIDENTS*

Update:

Well defined circulation moving back over the warm waters of the southern Gulf and increasing intensity is likely starting later this evening. Large plume of tropical moisture surrounding Alex will begin to spread moisture into the TX coast late tonight with more active thunderstorms on Monday.

What started this morning in the shifting of guidance northward has continued today with now the HWRF, GFS, and CMC all showing landfalls on the middle or upper TX coast, while the ECMWF shows around Tampico MX and the GFDL splits the difference toward Brownsville...an unsettling change of events from last night. Needless to say...and echoed by NHC...the forecast track confidence is below average and subject to some large changes. No real reason at this point to go with either track camps although the northern solutions seem a touch more possible given the upper air pattern and some strangeness in the ECMWF solution as the TC approaches the MX coast. The next 24 hours should really help firm up the track questions as the northern camp suggest a turn toward the NNW very soon and if ALEX continues toward the WNW, then these models will likely not verify. Error cone has shifted northward toward the Rockport area and may need to be adjusted a touch more northward if guidance continues its right trending, but Alex is going to have to start gaining some latitude if it is going to move more northward in the long run.

No real change in the intensity forecast, with a hurricane expected in the western Gulf. Could see Alex get stronger than currently forecast if it moves more northward allowing more time over the warm Gulf waters and favorable upper air conditions.

Impacts:

Based on the current NHC track and models showing large surge of tropical moisture on the east side of the system, expect rains to start to increase Monday as moisture surges inland with a contraction of rains Tuesday and then onset of squalls Wednesday and Thursday along the entire TX coast. Could see some heavy rains, but any flooding concerns at this point should be confined to S TX closer toward the inner core rains of Alex. With a large circulation expected wind and seas will be coming up along the entire TX coast along with coastal tides as large swells begin to reach the coast. Favored ENE to NE winds along the coast suggest some water level rise from SW LA to Matagorda Bay even if Alex goes into MX. Current track would likely keep tides below warning levels, but very uncertain at this moment.

Remember not to focus on the exact track of the black dots and instead the overall error cone as errors at Days 4-5 can be 200-300 miles. Additionally, a hurricane is not a point and effects can be far reaching from the landfall point.

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1958. USSINS
Quoting MrstormX:


Masters is a beast


He did what he had to do. Certainly, being the lead tropical weather site on the net, he would have been remiss not to state the obvious. Respect - he made a good decision.
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Quoting Tazmanian:
this blog will have 6000 commets by AM
No because Dr. Rob Carver will have an update tonight.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
hey any thing new with the HH my love
Member Since: May 21, 2006 Posts: 5091 Comments: 114776
1954. Levi32
Quoting CCkid00:

what is that big swirl in the atlantic...top right of the picture?


Ex-94L, a tropical wave interacting with a TUTT cell (upper low).
Member Since: November 24, 2005 Posts: 635 Comments: 26564
Quoting louisianaboy444:


Actually its the opposite...18z GFS shifted more towards the Central Texas Coast aligned with the 18z HWRF and GFDL I dont even think the CMC shows Southeast Texas or Louisiana anymore...all the models are zeroing in on the Central Texas Coast...Corpus Christi is a good bet


0Z CMC now goes right into the heart of LA
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Quoting Eaglesfan27:


Wow, I didn't realize anyone else from Prairieville was on here.

You would be suprised! lol. Alot of people here are from south Louisiana.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting WildWillyFL:
Is the track political? I been watching this site for a while. Over the last few days this storm has been late to classify and consensus track has never really been Mexico (for a stronger storm).

I will be the first one to admit steering currents and modeling is a crazy science, but when most say north, and NHC says south, it makes you wonder? Heck, very few of the experts here expect a landfall south of Texas (most models don't).


ive been thinking the same
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Quoting WildWillyFL:
Is the track political? I been watching this site for a while. Over the last few days this storm has been late to classify and consensus track has never really been Mexico (for a stronger storm).

I will be the first one to admit steering currents and modeling is a crazy science, but when most say north, and NHC says south, it makes you wonder? Heck, very few of the experts here expect a landfall south of Texas (most models don't).


Do you really think the NHC would post erroneous report for political reasons? That's not going to happen. To many people in involved to keep in under wraps. And I don't think they would do it anyway.
Member Since: August 26, 2006 Posts: 0 Comments: 1547
1948. Skyepony (Mod)
Quoting CCkid00:

what is that big swirl in the atlantic...top right of the picture?


Upper Level Low north of PR..
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Quoting CCkid00:

what is that big swirl in the atlantic...top right of the picture?


That's just a ULL (Upper Level Low)
Member Since: October 16, 2008 Posts: 0 Comments: 544
this blog is like moveing 300 commets per sac
Member Since: May 21, 2006 Posts: 5091 Comments: 114776
Quoting StormW:


With a lemon twist!
LOL!!
Member Since: September 2, 2009 Posts: 130 Comments: 21091
1944. hydrus
Quoting Levi32:


Probabilities are needed for a lot of things in weather forecasting but there is no need to try to be so specific with development potential, for instance. I go with "low" "moderate" or "high" chances of development. And making a probability forecast for landfall is kind of pointless....even the NHC just goes with a cone of uncertainty. That's all I do....section of coastline that it might make landfall on.
Did you read post#1626 Levi?
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Quoting USSINS:
Masters did good coming in with a late afternoon update reflecting the more northerly possibilities.


Masters is a beast
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Quoting alaina1085:

We are neighbors. Im in prairieville.


Wow, I didn't realize anyone else from Prairieville was on here.
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If you take care of the little people,you will get your life back!
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this blog will have 6000 commets by AM
Member Since: May 21, 2006 Posts: 5091 Comments: 114776
Alex is wasting no time filling in it's areas devoid of convection.
Member Since: October 16, 2008 Posts: 0 Comments: 544

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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.