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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1788. Patrap

00z Early Cycle NHC model tracks
Alex
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)





Dynamic Models (More sophisticated models)




Member Since: July 3, 2005 Posts: 424 Comments: 128279
Quoting CCkid00:


according to Dr. Masters, those models are not to be written off and there remains a possibility for a Texas, or even a SW La. landfall. i'm new on here...don't know who to believe. i've heard you are good, i've heard Dr. Masters is good and StormW.


Welcome from another fellow newb blogger. The ones to follow are Drak, Weather456, Dr. Masters, StormW and Levi32 IMO. Some other useful bloggers: Kman, Koritheman, RyanFSU, extreme236, hurricane23, Patrap, Ike and MississipiBoy from my previous years of blogging these ones are the good apples as well as many up and coming ones like MiamiHurricanes.
Member Since: October 16, 2008 Posts: 0 Comments: 544
what are they smoking 991 35kt that cant be right try more like more like 50kt
Member Since: May 21, 2006 Posts: 5091 Comments: 115097
1785. MZV
That western rain band is looking like the northern one did a few hours ago. Alex is wasting no time filling in. I think there wil be some sleepy bloggers tomorrow...
Member Since: Posts: Comments:
1783. jpsb
Quoting MZV:


I kind of disagree with that rule. Dean and Felix made beelines to the west. Ike curved a little but that was a fairly western-headed storm too.

The conditions drive things, but I do think exceptionally large storms are harder to forecast. We see fewer of them and they have less background data for modeling.
Allen monster hurricane, due west all the way into Mexico. Allen was as large as Alex.
Member Since: June 30, 2009 Posts: 0 Comments: 1191
Quoting IKE:


Jeez...he just got his toes in the water.

System is huge.

He pulled a Fay.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
This is definately not good news for Texas... A possible landfall over or near Galveston as a major hurricane on Friday??? NOT GOOD!
Member Since: Posts: Comments:
Quoting Tazmanian:
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 27 JUN 2010 Time : 231500 UTC
Lat : 19:24:01 N Lon : 91:06:23 W


CI# /Pressure/ Vmax
3.2 / 999.1mb/ 49.0kt


Final T# Adj T# Raw T#
2.8 3.2 3.2

Latitude bias adjustment to MSLP : +1.5mb

Center Temp : -3.1C Cloud Region Temp : -43.3C

Scene Type : CURVED BAND with 0.62 ARC in LT GRAY

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : OFF


Weakening flag on??
Member Since: September 2, 2006 Posts: 110 Comments: 6877
Quoting tropicfreak:


Will the NHC issue a special advisory soon.
If they feel like it is necessary, yes. If I were the NHC I would issue one, but that's just me.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
lets remember how close these pressure readings were to each other

wind is a difference in pressure, so the larger the difference in the pressures from one observation to the next, the higher the winds

that is why Alex can have a pressure of 991mb but only winds of about 40mph, because the decreases in pressure were gradual
Member Since: March 10, 2010 Posts: 1 Comments: 7688
1776. Levi32
Quoting Weather456:
Do you remember this storm?



Here's the problem though....the trough here may not be very far south but it is very amplified for this time of year. The resulting pattern supports the 500mb high center shifting east all the way to the Bahamas or farther east. The next ridge building behind the trough, which should curve Alex back westward, is supposed to be centered all the way up in the central plains near Iowa when it moves north of Alex. This leaves the door open for him to sneak far enough north to get into Texas, but anything to the right of Corpus Christi doesn't make much sense with the ridge directing the flow westward to its south.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Quoting Acemmett90:
taz am i reading this correctly a 991 mb ts with 40 mph haha naaa really atleast 65 mph winds when the winds catch up



yup
Member Since: May 21, 2006 Posts: 5091 Comments: 115097
1773. xcool
00z BAMS

WHXX01 KWBC 280014
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0014 UTC MON JUN 28 2010

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

TROPICAL CYCLONE ALEX (AL012010) 20100628 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
100628 0000 100628 1200 100629 0000 100629 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 19.2N 91.1W 20.4N 92.6W 21.2N 93.3W 21.7N 94.0W
BAMD 19.2N 91.1W 20.0N 92.1W 20.6N 92.9W 21.1N 93.7W
BAMM 19.2N 91.1W 20.1N 92.5W 20.8N 93.4W 21.2N 94.2W
LBAR 19.2N 91.1W 20.1N 92.3W 21.3N 93.8W 22.6N 95.6W
SHIP 35KTS 42KTS 51KTS 59KTS
DSHP 35KTS 42KTS 51KTS 59KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
100630 0000 100701 0000 100702 0000 100703 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 22.3N 94.7W 23.3N 95.7W 24.8N 96.4W 27.5N 96.7W
BAMD 21.7N 94.6W 22.7N 96.4W 23.5N 97.6W 24.8N 98.5W
BAMM 21.8N 95.0W 22.8N 96.2W 24.2N 97.0W 26.8N 97.2W
LBAR 24.0N 97.3W 26.8N 99.6W 29.5N 100.1W 32.0N 98.5W
SHIP 68KTS 84KTS 86KTS 79KTS
DSHP 68KTS 84KTS 48KTS 29KTS

...INITIAL CONDITIONS...
LATCUR = 19.2N LONCUR = 91.1W DIRCUR = 300DEG SPDCUR = 7KT
LATM12 = 18.6N LONM12 = 90.1W DIRM12 = 299DEG SPDM12 = 9KT
LATM24 = 17.5N LONM24 = 88.1W
WNDCUR = 35KT RMAXWD = 20NM WNDM12 = 30KT
CENPRS = 991MB OUTPRS = 1004MB OUTRAD = 200NM SDEPTH = D
RD34NE = 150NM RD34SE = 20NM RD34SW = 20NM RD34NW = 60NM

Member Since: September 26, 2009 Posts: 2 Comments: 15670
A vortex message will likely be released shortly...
Member Since: September 2, 2009 Posts: 130 Comments: 21193
1770. Patrap
Member Since: July 3, 2005 Posts: 424 Comments: 128279
1769. IKE
Quoting Ivanhater:
AL, 01, 2010062800, , BEST, 0, 192N, 911W, 35, 991, TS, 34, NEQ, 150, 20, 20, 60,

Tropical storm again


Jeez...he just got his toes in the water.

System is huge.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Alex a TS, again.

AL, 01, 2010062800, , BEST, 0, 192N, 911W, 35, 991, TS,


Will the NHC issue a special advisory soon.
Member Since: September 2, 2006 Posts: 110 Comments: 6877
Quoting louisianaboy444:
NHC has this storm reaching Hurricane Strength in 48 hours...i'm not buying that based on current organization i'd say 24 hours or so

Agree with ya there. Like the new pic.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting Tazmanian:
olny 35kt thats a littl low for a TS huh


35 knots is 40mph, TS strength
Member Since: March 10, 2010 Posts: 1 Comments: 7688
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 27 JUN 2010 Time : 231500 UTC
Lat : 19:24:01 N Lon : 91:06:23 W


CI# /Pressure/ Vmax
3.2 / 999.1mb/ 49.0kt


Final T# Adj T# Raw T#
2.8 3.2 3.2

Latitude bias adjustment to MSLP : +1.5mb

Center Temp : -3.1C Cloud Region Temp : -43.3C

Scene Type : CURVED BAND with 0.62 ARC in LT GRAY

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : OFF
Member Since: May 21, 2006 Posts: 5091 Comments: 115097
Quoting Tazmanian:
olny 35kt thats a littl low for a TS huh
It is a 40mph tropical storm.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Quoting victoriahurricane:


Indeed, which is amazing and definitely shocked a lot of the bloggers here, myself included. Do you have any clue as to why it remained so structurally sound, even improving it's sturcture with it's Yucatan trek? We all know that Fay was helped by the warm marshlands it went over, but what can the Yucatan provide? Maybe it was because he could easily tap waters and the energy on both sides of the Yucatan due to his size?


My personal opinion is that he was struggling to consolidate or tighten his circulation all along. The trip over the Yucatan was flat enough and surrounded by water. It was just enough friction to tighten the circulation, while remaining close enough to water to feed moisture into the storm.
Member Since: Posts: Comments:
NHC has this storm reaching Hurricane Strength in 48 hours...i'm not buying that based on current organization i'd say 24 hours or so
Member Since: August 29, 2006 Posts: 22 Comments: 1352
Quoting MiamiHurricanes09:
Alex a TS again.

AL, 01, 2010062800, , BEST, 0, 192N, 911W, 35, 991, TS,


No surprise. It's official, alex is back to TS strength.
Member Since: September 2, 2006 Posts: 110 Comments: 6877
olny 35kt thats a littl low for a TS huh
Member Since: May 21, 2006 Posts: 5091 Comments: 115097
Quoting CCkid00:

i think it already has!!! LOL not sure what to believe! sure fun to watch.....i've been watching in here ALL day...can't seem to pull away. my husband and kids say i'm a weather addict!


LOL!! I have been tracking Alex all day myself and I can't pull myself away either..not even for 10 minutes!! What do you think about Alex???
Member Since: June 16, 2008 Posts: 0 Comments: 507
1753. Patrap


TS Bill 2003
Member Since: July 3, 2005 Posts: 424 Comments: 128279
evening all. From quickly scanning the posts, looks like Alex could be turning more Northerly as it hits the warm Gulf waters? Last I had read Mexico would take the hit. What is the lowest pressure recon has found so far? I think a lot of Gulf residents may be taken by surprise with the Monday morning news.
Member Since: September 5, 2007 Posts: 0 Comments: 3488
Quoting Ivanhater:
AL, 01, 2010062800, , BEST, 0, 192N, 911W, 35, 991, TS, 34, NEQ, 150, 20, 20, 60,

<<




looks like where back too a TS
Member Since: May 21, 2006 Posts: 5091 Comments: 115097
Quoting Patrap:


Hermaine from 03 maybe..wasnt much


Hermine wasn't used that year, it was henri.
Member Since: September 2, 2006 Posts: 110 Comments: 6877
Alex a TS, again.

AL, 01, 2010062800, , BEST, 0, 192N, 911W, 35, 991, TS,
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Quoting Ivanhater:
AL, 01, 2010062800, , BEST, 0, 192N, 911W, 35, 991, TS, 34, NEQ, 150, 20, 20, 60, <<


Officially Tropical Storm Alex. Pressure's amazing though.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
No. That is from yesterday. Although I wouldn't be surprised to see a vortex message pop up soon.



ok i no now guys thanks
Member Since: May 21, 2006 Posts: 5091 Comments: 115097
Quoting Weather456:
Do you remember this storm?



that was Bill from 2003
Member Since: March 10, 2010 Posts: 1 Comments: 7688
Quoting Tazmanian:
000
URNT12 KNHC 261919
VORTEX DATA MESSAGE AL012010
A. 26/19:08:30Z
B. 17 deg 19 min N
087 deg 28 min W
C. 925 mb 655 m
D. 56 kt
E. 182 deg 29 nm
F. 237 deg 52 kt
G. 181 deg 26 nm
H. EXTRAP 996 mb
I. 19 C / 755 m
J. 24 C / 764 m
K. 22 C / NA
L. NA
M. NA
N. 1345 / 9
O. 0.02 / 4 nm
P. AF302 0301A ALEX OB 09
MAX FL WIND 52 KT S QUAD 18:59:50Z
SLP EXTRAP FROM 925 MB



is this new?


No Taz its from 2pm CDT :O)!!
Member Since: Posts: Comments:
1741. Hhunter
Member Since: Posts: Comments:
Quoting Levi32:


He has the appearance of a Cat 2+ hurricane that went over the Yucatan.


Indeed, which is amazing and definitely shocked a lot of the bloggers here, myself included. Do you have any clue as to why it remained so structurally sound, even improving it's sturcture with it's Yucatan trek? We all know that Fay was helped by the warm marshlands it went over, but what can the Yucatan provide? Maybe it was because he could easily tap waters and the energy on both sides of the Yucatan due to his size?
Member Since: October 16, 2008 Posts: 0 Comments: 544
question why did the NHC in there 805edt discussion say est pressure 999mb when they had a reading from HH of 991MB?
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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.