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: 288 - 238

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 Hurricanes101:
Its pretty clear to me that Alex is moving between WNW and NW now, not sure what this barely north of due west is that some are seeing


Go to this satellite loop

Click on trop pts and tell me the COC is not moving west of the forecast points. Maybe my eyes are broken but I doubt it...
Member Since: Posts: Comments:
Alex will be a hurricane by 8pm tomorrow night, i personally don't think the landmass disrupted the circulation significantly, too large of a system and drawing moisture from every quadrant.
Member Since: Posts: Comments:
Quoting Levi32:
Alex's forward movement has slowed during the last 3 hours, indicating a northward turn in course is imminent, if not already occurring.



yup
Member Since: Posts: Comments:
Alex's forward movement has slowed during the last 3 hours, indicating a northward turn in course is imminent, if not already occurring.
Member Since: Posts: Comments:
Quoting Hurricanes101:


I think that was a glitch more than anything


Yeah their center fix got off and then they changed it in the last few frames..
Member Since: Posts: Comments:
Quoting neonlazer:


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.


Why.... Do you have family in South TX?
Member Since: Posts: Comments:
Quoting Jeff9641:


I think so with some of the heaviest rain on the west side of FL as a deep SW flow sets up. This could day and night storms training ashore in a couple of days.


Sounds fun. :)
Member Since: Posts: Comments:
I do think that wave over Africa is poised to be 95L in a day or two

The fact the NHC is already mentioning it (per 205 discussion) is pretty telling to me

Would not be totally shocked to see a circle on it if it maintains in a few days
Member Since: Posts: Comments:
Disregard the plot, hasn't updated yet, but you can clearly see the center is moving off the coast.

Member Since: Posts: Comments:
Quoting CADZILLA:
The last time I cut back my trees we were hit by Ike the next week, I cut back my trees last week.

This will make a great story for Monday morning news.
lol. Isnt it weird how that happens. You will never cut my trees. :)
Member Since: Posts: Comments:
Quoting HurricaneSwirl:


Oh ok thanks.

One invest down, and another one's coming right along in post 252




soon it will not even off land yet
Member Since: Posts: Comments:
That is the 18 z run not the 12z. it is on the map.
Member Since: Posts: Comments:
Quoting Stormchaser2007:



You see post 240 and 254?


Yup I saw the 12z Euro a while ago. Still holding west....some of the ensemble members are starting to hit Texas though so we'll see if the operational run starts shifting north a little bit tonight and tomorrow.
Member Since: Posts: Comments:
Quoting WinterAnalystwx13:


when you guys make your own maps, you need to put somewhere its from you from your own opinion....don't need to have people and lurkers on here believing your track is a nhc track and panicking prematurely...
Member Since: Posts: Comments:
Quoting Tazmanian:



nop


Oh ok thanks.

One invest down, and another one's coming right along in post 252

Member Since: Posts: Comments:
No COC relocation Alex center has been moving west since 1815 zulu.
..maybe I am blind !
;=)
Member Since: Posts: Comments:
with the hot waters of the gulf watch this thing take off fasts
Member Since: Posts: Comments:
Quoting lopaka001:


Unless I am looking at the wrong COC I got Alex moving west now and it doesn't look a like a jog either..


It is NOT moving due west.
Member Since: Posts: Comments:
Quoting Hurricanes101:
Its pretty clear to me that Alex is moving between WNW and NW now, not sure what this barely north of due west is that some are seeing


Agreed if anything the circulation got broad and relocated ever so slightly to the north just off/barely on the coast
Member Since: Posts: Comments:
Quoting Hurricanes101:
Its pretty clear to me that Alex is moving between WNW and NW now, not sure what this barely north of due west is that some are seeing


Me too, it's moving more to the NW than it was 3 hours ago.
Member Since: Posts: Comments:
Quoting Stormchaser2007:
12z ECMWF



Well it doesn't always get its forecasts right. Although it could be right and the CMC/GFS aren't idk.
Member Since: Posts: Comments:
The last time I cut back my trees we were hit by Ike the next week, I cut back my trees last week.

This will make a great story for Monday morning news.
Member Since: Posts: Comments:
Quoting HurricaneSwirl:


I remember far back when it was declared an invest it started out with 1013 mb, did it ever go below that?



nop
Member Since: Posts: Comments:
Its pretty clear to me that Alex is moving between WNW and NW now, not sure what this barely north of due west is that some are seeing
Member Since: Posts: Comments:

Quoting Levi32:
Alex is on top of the coastline.



You see post 240 and 254?
Member Since: Posts: Comments:
Quoting Tazmanian:



94L nevere got in past 25kt and it nevere got in pass 20% on the nhc site


I remember far back when it was declared an invest it started out with 1013 mb, did it ever go below that?
Member Since: Posts: Comments:
Alex is on top of the coastline.

Member Since: Posts: Comments:
Quoting wfyweather:


No he is moving wnw and that hasnt changed


Unless I am looking at the wrong COC I got Alex moving west now and it doesn't look a like a jog either..
Member Since: Posts: Comments:
Standard operating procedures is to evac when there is a storm in the Gulf.
Member Since: Posts: Comments:
12z ECMWF

Member Since: Posts: Comments:
Quoting Jeff9641:


I think so with some of the heaviest rain on the west side of FL as a deep SW flow sets up. This could day and night storms training ashore in a couple of days.


I keep holding back watering my veggie garden in Brandon, but the rain keeps missing me. I think the mall has built up a microclimate that pushes the rain to the north and south :P
Member Since: Posts: Comments:
Quoting Stormchaser2007:
12z ECMWF is still south of the border.



Far south of the border. Wasn't it more northerly earlier? Are we beginning to see a southern shift?
Member Since: Posts: Comments:
Quoting DestinJeff:
COC relocates back onshore in the last frame of the Dvorak loop


I think that was a glitch more than anything
Member Since: Posts: Comments:
Quoting StormW:


What 2:00 p.m. forecast?
Good Afternoon StormW. Can you please tell me what is going on in the Caribbean between 70W and 80W. Windsat looks interesting to me.
Member Since: Posts: Comments:
I'm looking at the rainbow floater loop on the NHC satellite imagery and it looks like Alex is moving definitely west of the forecast points. Not to say it's going to continue to do that but right now that's what I see. When is it supposed to be pulled northward?
Member Since: Posts: Comments:
Hmmm ... NOLA is what I said this morning.

Member Since: Posts: Comments:
Quoting HurricaneSwirl:


Where can I get an archive on 94L? I want to see how strong it got, no one posted it's strength updates because we were so caught up on Alex.



94L nevere got in past 25kt and it nevere got in pass 20% on the nhc site
Member Since: Posts: Comments:
Quoting CosmicEvents:
I'd be kinda' sick if I was anywhere from Corpus to Nola right now...and I'm sick about the oil and what that means to those it effects directly and indirectly(all of us).
.
But, as much as I dislike the NHC forecaster Brennan, it's best to keep in mind this tidbit from his last discussion. ALL OF THE MODEL UNCERTAINTY WITH THE TRACK OF ALEX OFFERS A
REMINDER TO NOT TO FOCUS ON THE EXACT FORECAST TRACK...PARTICULARLY
IN THE EXTENDED PART OF THE FORECAST PERIOD...WHERE AVERAGE
FORECAST ERRORS CAN BE 200 TO 300 MILES.
.
.
This could very well be a cyclone that effects the cows in South Texas the most.
LoL too funny!
Member Since: Posts: Comments:
Quoting Hurricanes101:
invest_DEACTIVATE_al942010.ren

bye bye 94L


Where can I get an archive on 94L? I want to see how strong it got, no one posted it's strength updates because we were so caught up on Alex.
Member Since: Posts: Comments:
12z ECMWF is still south of the border.

Member Since: Posts: Comments:
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:

Viewing: 288 - 238

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.