Alex may head north to Texas or Louisiana

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

Share this Blog
5
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 238 - 188

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73Blog Index

Quoting StormW:


What 2:00 p.m. forecast?


Why not take it out? I think they are pulling a Ike forecast.... do not know where it is going
Member Since: Posts: Comments:
To add to the uncertainty, HPC Extended Forecast Discussion

Excerpt:


THE 12Z GUIDANCE IS SPLIT ON THE FATE OF ALEX AND ITS REMNANTS FOR
THIS FORECAST PERIOD. THE GFS...PARALLEL GFS...GEFS MEAN...AND
GEM GLOBAL ALL DIRECT EITHER ALEX OR A SPIN OFF LOW INTO THE
WESTERN GULF COAST DURING THE PERIOD...WITH THE UKMET AND ECMWF
TRACKING ALEX WESTWARD INTO MEXICO WITH NO FURTHER ADO. WITH THE
TYPICALLY STRONG PERFORMING ECENS MEAN ALLOWING FOR AT LEAST A
MODEST NORTHBOUND AREA OF DISTURBED WEATHER EMERGING FROM THE
GULF...FELT SOME REFLECTION OF THE RIGHT TURNING MODELS SHOULD BE
INCORPORATED INTO THE FINAL PRODUCTS TODAY. SENT WHAT AMOUNTS TO
A SPIN OFF LOW UP THROUGH TEXAS AND THE EASTERN PLAINS DAYS 4
THROUGH 7...WITH ANOTHER LOW LEVEL CIRCULATION FOLLOWING THE TPC
TRACK OF ALEXS HEART INTO NORTHERN MEXICO EARLY IN THE PERIOD.
THE GFS GUIDANCE LOOKS LIKE IT IS SUFFERING FROM CONSIDERABLE GRID
SCALE FEEDBACK OVER THE EASTERN GULF STATES...WITH THE DOUBLE
DIGIT RAINFALL TOTALS NOT SUPPORTED. ELSEWHERE...NO BIG SURPRISES
IN THE NEW MODELS WITH THE MAIN BAND OF WESTERLIES...WITH THE OLD
ECENS MEAN STILL AFFORDING THE MOST STABLE SOLUTION.

Member Since: Posts: Comments:
Quoting WaterWitch11:
afternoon all,

i thought anytime a storm comes through the gulf they evacuate the platforms?


Why do they need to evacuate the platforms in the Gulf for Alex? Its headed to Mex/TX???
Member Since: Posts: Comments:
Quoting jasoniscoolman09:
INVEST95L IS STILL ON LAND..


Its not even an invest yet.
Member Since: Posts: Comments:
invest_DEACTIVATE_al942010.ren

bye bye 94L
Member Since: Posts: Comments:
Quoting Jeff9641:
Interesting WV is depicting an ULL over SW LA guys Alex may be further east more like NOLA area very similar to CMC model. Upper level flow is now pulling deep tropical moisture toward FL. HPC folks are calling for 5 to 8" of rain across C and N FL over the next several days.


Hey Jeff! I am shocked by these new models. So you think we'll get that much rain in Tampa?
Member Since: Posts: Comments:
.............Looking stormier by the minute..
Member Since: Posts: Comments:
Quoting WinterAnalystwx13:


Alex is almost moving NW.


No he is moving wnw and that hasnt changed
Member Since: Posts: Comments:
Quoting jasoniscoolman09:
INVEST95L IS STILL ON LAND..




there is no 95L
Member Since: Posts: Comments:
there is no invest 95L
Member Since: Posts: Comments:
Quoting RitaEvac:
Looks like BS



I honestly think we can pretty much through out the GFDT and GFDL, because Alex would have to start moving nearly due N right now to follow those. The other northern model tracks are possible though.
Member Since: Posts: Comments:
Quoting WinterAnalystwx13:


Alex is almost moving NW.


Alex COC looks to be moving West to me..
Member Since: Posts: Comments:
Quoting Jeff9641:
Interesting WV is depicting an ULL over SW LA guys Alex may be further east more like NOLA area very similar to CMC model. Upper level flow is now pulling deep tropical moisture toward FL. HPC folks are calling for 5 to 8" of rain across C and N FL over the next several days.


It was there yesterday on WV
Member Since: Posts: Comments:
Quoting Tazmanian:




there is no 2pm update that map is still from 10am


But why not take it out?
Member Since: Posts: Comments:
poor BP and TX
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting LouisianaWoman:
The wait and see game sucks. Always keeps my stomach in knots and my hands incapable of staying steady.


Yep, I am in south central louisiana and i got my laptop out and if someone look a pic of me right now..I got 6 half screen windows open..4 different satellites, NHC advisory on autorefresh and this blog. I will say one thing, I feel for the real NHC people..their job must be so stressful.
Member Since: Posts: Comments:
Looks like BS

Member Since: Posts: Comments:
Quoting Levi32:


None. Alex will need time to reorganize. By tomorrow night it could be back up to the intensity it was at landfall in the Yucatan.


It is a good thing the S GOM is not as warm as the NW Caribbean or I'd be worried of faster development.
Member Since: Posts: Comments:
Quoting WaterWitch11:
afternoon all,

i thought anytime a storm comes through the gulf they evacuate the platforms?
I think I heard the platforms were starting to evac this past friday.
Member Since: Posts: Comments:
Is Alex moving on a more western track now?
Member Since: Posts: Comments:
Quoting superweatherman:
StormW
Why do you think that the 2pm forecast?






there is no 2pm update that map is still from 10am
Member Since: Posts: Comments:
hi storm
Member Since: Posts: Comments:
The wait and see game sucks. Always keeps my stomach in knots and my hands incapable of staying steady.
Member Since: Posts: Comments:
Ok, so I lurked some yesterday and was confident this was a Mexico storm. Dr. Masters headline has me scratching my head. What changed? I certainly hope this storm doesn't go north. Wow, I guess this is just proof that you can't take your eyes off of a tropical system ever.
Member Since: Posts: Comments:
StormW
Why do you think that the 2pm forecast?


Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
The lack of convection near the center will inhibit rapid strengthening immediately upon moving offshore, however.
Also remember he mentions that it will probably need to be 100 miles offshore before it hits the warmest water..but that 100 miles might allow it to organize..before it explodes.
Member Since: Posts: Comments:
well i guess with interests in brownsville area we should stay very alert...
Member Since: Posts: Comments:
202. xcool


Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting Tazmanian:
Levi32 whats the ch of wakeing up and finding a strong cat 2 storm in the AM


None. Alex will need time to reorganize. By tomorrow night it could be back up to the intensity it was at landfall in the Yucatan.
Member Since: Posts: Comments:
Thanks USSINS and StormW...

Check back later. I'm off to get ice cream treats with the fam. :)
Member Since: Posts: Comments:
Quoting 1900hurricane:
Interesting... Thanks for the update Dr. Masters!
Ths storm is entering the Gulf as we speak,the last couple hours it was moving Northwest...
Member Since: Posts: Comments:
GOM 84 Hour Wave Forecast (using MIKE21)
Member Since: Posts: Comments:
1825 1 W ELMWOOD PARK RACINE WI 4269 8784 TREES DOWN ON GREEN RIDGE DRIVE AND SOUTHWOOD DRIVE. FUNNEL CLOUD ALSO REPORTED IN THE AREA. (MKX)

1830 4 N CARLETON WAYNE MI 4211 8340 ROOF DAMAGE, POWER LINES DOWN, STRUCTURAL DAMAGE AT WILLOW AND WALTZ RD. (DTX)
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Levi32 whats the ch of wakeing up and finding a strong cat 2 storm in the AM
Member Since: Posts: Comments:
Quoting StormW:
Hi Levi;Taz!


Hey Storm!
Member Since: Posts: Comments:
Member Since: Posts: Comments:

Viewing: 238 - 188

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73Blog Index

Top of Page

About

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

Local Weather

Overcast
27 °F
Overcast