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 Levi32:


Wouldn't describe it as pinhole....just a small eye, and yes it did develop one. It strengthened over land which was quite a site to see for those of us who were awake to witness.
Fay all over again man, lol.
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1637. Levi32
They got a nice pass into the center and right back out again due to proximity to land.

Member Since: November 24, 2005 Posts: 635 Comments: 26647
Is it Weather456 predicting a N Mexico landfall and Alex will NOT hit Texas?

I think it is premature to be dropping landfall locations for Alex. 3-4 days out there is always a large forecast error spread. This could hit N Mexico but then again it is not wise to rule out other possibilies. Dr. Masters always thows out percentages such as: 70% change of hitting XXX and 30% change of hitting XXX ext.
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Quoting Levi32:


Oh ya...forgot about that. They may still issue a statement upgrading it.
They should considering the 8 millibar discrepancy in the advisory and what recon found. Guess we'll see.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
1634. angiest
Quoting jpsb:
Ike eye went right over me, took almost an hour, Ike's winds were not that much, maybe cat 2 (Rita was stronger) but boy oh boy he's surge was a monster!


I live in Katy. We had some pretty impressive wind damage all the way out here on the weak side of the storm.

At the start of last hurricane season, work had Dr. Neil Frank out to talk about hurricanes, and he as much as stated that the NHC should have used pressures when stating Ike's category because all the evidence was pointing toward him being stronger than the winds indicated.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1632. srada
Good Evening everyone!!

if we have a stronger storm (category 3/4), then we might be looking at the first early runs of models where it had it hitting florida..makeing a loop de loop in the gulf of mexico where everyone on the coast of the GOM gets at least ts winds..and no I dont live in florida
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1631. Patrap





Member Since: July 3, 2005 Posts: 423 Comments: 128225
Keep your eye on this buoy as Alex will pass very close to it. 1004 and falling yet Alex is still about 180 miles away from it..

Member Since: August 19, 2006 Posts: 0 Comments: 15813
Quoting MrstormX:
Its hardly off the shore and already 991, makes you wonder what the open water has in store for Alex.


Lets not even think about that. its bad enough when its partially over land and other half over water, but in the open, I can't even imagine how powerful or monstrous it would be.
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Quoting Levi32:
7pm CDT advisory should be out soon now that the recon has penetrated the center, and should upgrade Alex back to a tropical storm.

Sorry Levi32. Next NHC update is 10PM CDT per NHC. Unless there is a Special Advisory!!
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Until I see this kind of movement, I aint worrying

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1626. hydrus
Quoting Levi32:


It honest-to-goodness was. It was apparent on radar as well...no doubt it was an eye.
Well when it is time to re-evaluate Alex, it is a good bet they will upgrade it to hurricane status. I have never seen an eye that small and perfect in a tropical storm. And I have seen my share.
Member Since: September 27, 2007 Posts: 1 Comments: 21173
Quoting StormW:


Well, until I see a change in steering layers forecast maps, and what's happening out west, I think at the moment, he's gonna come NNW for a short term, then head back with a more westerly component. I can't commit right now to a definite location, until he gets it all back together. Give me about another 18-24 hours, and I should be able to have a better handle on track.


Understood..:) Thank you Senior Chief !! :) Much appreciated..:)
Member Since: June 16, 2008 Posts: 0 Comments: 507
1623. Patrap
Member Since: July 3, 2005 Posts: 423 Comments: 128225
Quoting MiamiHurricanes09:
There is no intermediate advisory because there are no watches or warning warranted.


Ok this is the second or third time today we have posted nearly the exact same thing at the exact same time. We've gotta stop that LOL
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1621. Levi32
Quoting MiamiHurricanes09:
There is no intermediate advisory because there are no watches or warning warranted.


Oh ya...forgot about that. They may still issue a statement upgrading it.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Quoting MrstormX:
Vertical Stacking is already going crazy...
What do you mean by this statement? That it is becoming vertically stacked at a rapid pace or is the vertical structure off a bit?
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Looks like that trough is digging into the ridge pretty good. If Alex strengthens any more this is the steering flow:



Member Since: December 18, 2006 Posts: 7 Comments: 2686
Quoting tropicfreak:


Fine, yet hot here in commonwealth VA, and yet no rain to speak of over the past 2 weeks.


almost to 103 again today...freaking miserable outside...
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1617. Patrap
Member Since: July 3, 2005 Posts: 423 Comments: 128225
1615. Levi32
Quoting TankHead93:
Do you mean to tell me this thing developed what appears to be a pinhole eye last night over the Yucatan Peninsula?


Wouldn't describe it as pinhole....just a small eye, and yes it did develop one. It strengthened over land which was quite a site to see for those of us who were awake to witness.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Quoting tropicfreak:


Fine, yet hot here in commonwealth VA, and yet no rain to speak of over the past 2 weeks.


WOW! That doesn't sound too good..:(
Member Since: June 16, 2008 Posts: 0 Comments: 507
Quoting Levi32:
7pm CDT advisory should be out soon now that the recon has penetrated the center, and should upgrade Alex back to a tropical storm.


No intermediate advisories for now.
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Quoting Levi32:
7pm CDT advisory should be out soon now that the recon has penetrated the center, and should upgrade Alex back to a tropical storm.
There is no intermediate advisory because there are no watches or warning warranted.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Quoting RecordSeason:
1569:

They are the same in principle once they get going, but the manner in which they form is not necessarily the same.

"Alex" formed from a massive tropical wave(93L,) which absorbed several other tropical waves back when it was in the eastern and central Caribbean.

I gotta tell you, I was watching the whole time, and there was some FREAKY oscillations of convection going on back then on the color enhanced infrared.


That was the most confusing invest i have ever tracked.
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1610. help4u
Mexico it is then Rita Vac!
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Its hardly off the shore and already 991, makes you wonder what the open water has in store for Alex.
Member Since: May 27, 2009 Posts: 0 Comments: 4438
1608. Patrap

RGB
Member Since: July 3, 2005 Posts: 423 Comments: 128225
Quoting MrstormX:


Rapid Intensification?


I expect rapid intensification (deepening), if any, to occur after 36 hrs where ocean heat content is highest. For now, a drastic increase in winds (rapid strengthening) would be the result of the positive feedback to the low pressure, nothing more, nothing less.
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I would say Alex is already a tropical storm. Recon found uncontaminated 40mph winds and a pressure of 991.0mb.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Quoting Joanie38:


Evening Tropicfreak..:) How are you??


Fine, yet hot here in commonwealth VA, and yet no rain to speak of over the past 2 weeks.
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Quoting bohonkweatherman:
I think a Stronger storm has a better chance to move more north than a weaker storm?

Exactly right. The stronger the storm the more north they go. Weaker the more west.
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Quoting Levi32:
Alex developing an eye northwest of Belize at 07:45UTC last night:

Do you mean to tell me this thing developed what appears to be a pinhole eye last night over the Yucatan Peninsula?
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1600. Levi32
Quoting hydrus:
And that really is an eye right?


It honest-to-goodness was. It was apparent on radar as well...no doubt it was an eye.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Does anybody listen to Weather456 and StormW? you dont hear them saying its going to TX much less LA
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1598. Levi32
7pm CDT advisory should be out soon now that the recon has penetrated the center, and should upgrade Alex back to a tropical storm.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
I'm glad I had a good nap before the show.
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Quoting Patrap:
991mb Respectable and down a lot after a Land crossing.

A testament to Alex's voracity and size.



Looks like its wrapping around itself.
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Quoting tropicfreak:


Evening Joanie.


Evening Tropicfreak..:) How are you??
Member Since: June 16, 2008 Posts: 0 Comments: 507
Quoting Patrap:
991mb Respectable and down a lot after a Land crossing.

A testament to Alex's voracity and size.


Nice satelite image. Holding my breath for this one Pat.
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Vertical Stacking is already going crazy...
Member Since: May 27, 2009 Posts: 0 Comments: 4438
1591. hydrus
Quoting bohonkweatherman:
I think a Stronger storm has a better chance to move more north than a weaker storm?
You think right.
Member Since: September 27, 2007 Posts: 1 Comments: 21173
1590. aquak9
wonder what the folks inside the plane are thinking right now...
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1589. jpsb
Quoting angiest:

Ike's winds didn't catch up with his pressure, but the storm still did damage closer to the what the pressure indicated than the winds.
Ike eye went right over me, took almost an hour, Ike's winds were not that much, maybe cat 2 (Rita was stronger) but boy oh boy he's surge was a monster!
Member Since: June 30, 2009 Posts: 0 Comments: 1190
1588. xcool
bohonkweatherman yep
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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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