Alex slowly organizing; a Texas or Mexico landfall most likely

By: Dr. Jeff Masters , 28. kesäkuuta 2010 klo 14:13 (GMT)

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Tropical Storm Alex is slowly growing more organized as it steams away from Mexico's Yucatan Peninsula. Satellite loops show that Alex's heavy thunderstorms have increased in areal extent over the past few hours, and low level spirals bands are beginning to form to the south and north. The clockwise flow around an upper-level high pressure system a few hundred miles west of Alex is bringing about 15 knots of wind shear to the storm, which is slowing intensification, and limiting heavy thunderstorm activity on the storm's northwest side. Sea Surface Temperatures are very warm, 29°C, and there is some dry air to the northwest of Alex that may be inhibiting development. The latest Hurricane Hunter center fixes, at 6:32 am CDT and 7:16 am CDT, both had central pressures of 989 mb, with top surface winds in the 50 - 55 mph range.


Figure 1. Alex over the Yucatan Peninsula on Sunday, June 27, as seen by NASA's Aqua satellite. Image credit: NASA.

Track forecast for Alex: which model should you trust?
Our most reliable computer models have come into much better agreement this morning. A consensus forecast arrived at by averaging together most or all of the tracks of our top models--the GFS, ECMWF, GFDL, NOGAPS, HWRF, UKMET, and Canadian--is pretty much what NHC always uses as the basis of their forecast. This consensus forecast has narrowed in on the region near the Texas/Mexico border as being the most likely landfall location, with the usual cone of uncertainty surrounding it. The northernmost landfall location is Port O'Connor, as predicted by the Canadian model. The southernmost landfall location is near Tampico, Mexico, as predicted by the ECMWF model. Alex's landfall time varies from Wednesday evening to Thursday morning. Which model should you trust? Last year, the best performing models at the 3 day forecast period were the GFS, Canadian, ECMWF, and GFDL. Three out of four of those models are predicting a landfall between Brownsville and Corpus Christi, with only the ECMWF model predicting a landfall well south of the Texas border. With steering currents relatively weak, the uncertainty in landfall location is high. The average error in an NHC 72-hour track forecast last year was 230 miles, which is about the distance from Brownsville to Port O'Connor. Consider also that the NHC cone of uncertainty is the region where 2/3 of the time (using the last 5 years of statistics) the center of a storm will go. That means that 1/3 of the time a storm will not be in the cone of uncertainty. Given the slow motion of Alex and the recent uncertainty of the computer models, people living just beyond the edge of the cone of uncertainty should not be confident yet that Alex will miss them.

To get the probability of receiving tropical storm force winds or hurricane force winds for your location, I recommend the NHC wind probability forecasts. The 5am EDT (09 UTC) wind probability product predicted that Brownsville, Texas had the highest odds of getting a direct hit from Alex:

Brownsville, TX: 64% chance of tropical storm conditions (winds 39+ mph), 14% chance of hurricane force winds (74+ mph). This is the cumulative probability through Saturday morning. The wind probability forecasts also include separate probabilities for each 12-hour period between now and three days from now, and each 24 hours for the period 4 - 5 days from now.

La Pesco, MX: 59% tropical storm, 9% hurricane.

Tampico, MX: 42% tropical storm, 6% hurricane.

Corpus Christi, TX: 38% tropical storm, 5% hurricane.

Freeport, TX: 23% tropical storm, 2% hurricane.

Galveston, TX: 18% tropical storm, 1% hurricane.


Figure 2. Skill of computer model forecasts of 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.

Intensity forecast for Alex
Alex is currently over a region of ocean with relatively low total ocean heat content (about 10 - 30 kJ/cm^2). By Tuesday and Wednesday, the heat content will increase to 40 - 70 kJ/cm^2, which is high enough to allow Alex to rapidly intensify. Wind shear is currently a moderate 15 knots, and is projected by the SHIPS model to decrease to the low range, below 10 knots, on Tuesday and Wednesday. The combination of low wind shear and high ocean heat content should allow Alex to intensify into a hurricane. NHC is giving Alex an 81% chance of being a hurricane on Wednesday morning, and a 17% chance it will be a major hurricane at that time. Water vapor satellite images, though, show plenty of dry air over Texas and the adjoining waters, and this dry air may turn out to be a significant detriment to Alex. Another factor limiting Alex's intensification may be that the atmosphere is more stable than usual right now--temperatures at 200 mb are a rather warm -50°C, and are expected to warm an additional 1 - 2 degrees by Wednesday. Another factor limiting Alex's intensification may be its slow forward speed. Alex is moving at just 6 mph, and it would not take much of a slackening of the steering currents to stall out the storm. A slow-moving storm tends to pull up cold water from the depths, limiting intensification. In fact, the ECMWF model predicts that Alex could stall out right at landfall on Thursday. In short, Alex has the potential to intensify into a major hurricane, but there are plenty of roadblocks that make this only a 20% probability in my estimation.

Elsewhere in the tropics
None of the reliable computers models is calling for tropical storm formation over the the next seven days in the Atlantic.

Wind and ocean current forecast for the BP oil disaster
It currently appears that Alex will not directly affect the oil slick location, other than to bring 2 - 4 foot swells to the region on Wednesday. However, because Alex is such a deep low pressure region, strong east to southeast winds of 20 - 25 knots will develop over the oil slick region today through Thursday, according to the latest marine forecast from NOAA. The resulting currents should act to push oil to the west and northwest onto portions of the Louisiana, Mississippi, and Alabama coasts, according to the latest trajectory forecasts from NOAA and the State of Louisiana. Oil will also move westward along the central Louisiana coast towards the Texas border.

Resources for the BP oil disaster
Map of oil spill location from the NOAA Satellite Services Division
My post, What a hurricane would do the Deepwater Horizon oil spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
NOAA's interactive mapping tool to overlay wind and ocean current forecasts, oil locations, etc.
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Synthetic Aperture Radar (SAR) imagery from the University of Miami

Portlight continues its Haiti response
Hurricane season is here, and Haiti is not ready. Over 1.5 million Haitians are living outside in tents or under tarps, and are highly vulnerable to a hurricane. Portlight is working on constructing steel shelters out of shipping containers for homeless Haitians, as detailed in the Haitian Relief Recap blog post. Please visit the Portlight.org web site or the Portlight blog to learn more and to donate to Portlight's efforts in Haiti.


Figure 3. Still frame from the remarkable video taken inside the Haitian Presidential Palace during the 2010 earthquake.

To remind people of just how devastating the earthquake was, the Haitian government released a a href= video earlier this month showing the inside of the Haitian Presidential Palace during the mighty Haitian earthquake.

Next post
I'll have an update between 2 - 3pm CDT today, when the next set of model runs will be available.

Jeff Masters

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1215. StormVV
29. kesäkuuta 2010 klo 23:30 (GMT)
Oops wrong blog
1214. CaribbeanIslandStorm
28. kesäkuuta 2010 klo 20:47 (GMT)
Quoting tropicfreak:


TWC probably put him in the wrong spot, as they thought it would hit LA, what a big joke TWC is, can't track hurricanes correctly.

he's there because of the effects this storm can have on the oild spill, not because they are expecting a direct hit. ;-)
1213. MrNatural
28. kesäkuuta 2010 klo 20:25 (GMT)
Alex is very clearly developing an eyewall on the north side.
Member Since: 28.07.2009 Posts: 0 Comments: 220
1212. hurricanejunky
28. kesäkuuta 2010 klo 20:09 (GMT)
Spoke to CycloneOz just now. He's looking for a go / no-go for a Brownsville,TX landfall and storm chase deployment. He's got to leave soon if he's going. All advice and insight welcome either on here, my blog or via WUmail.

Also, any Brownsville residents please contact me via my blog or WUmail as I need some help from you.
Member Since: 28.08.2006 Posts: 6 Comments: 2895
1211. CJC111
28. kesäkuuta 2010 klo 20:07 (GMT)
Just a quick question for those in the know. Alex took a while trying to decide if it wanted to develop and has slowly wandered more than once. Is there reason to believe, whether it's MX or TX, that it will speed up once it gets a bit north? Because it's so slow and so big, the amount of rain could be large, widespread and devastating.
1210. SeALWx
28. kesäkuuta 2010 klo 20:03 (GMT)
On second thought...
Everyone stay here,
the new blog is overrated!
Member Since: 2.04.2010 Posts: 0 Comments: 196
1209. MiamiHurricanes09
28. kesäkuuta 2010 klo 20:03 (GMT)
Quoting cg2916:
NEW BLOG!!!
LOL! Told ya.
Member Since: 2.09.2009 Posts: 130 Comments: 21032
1208. cg2916
28. kesäkuuta 2010 klo 20:00 (GMT)
NEW BLOG!!!
Member Since: 21.12.2007 Posts: 13 Comments: 3026
1207. Hurricanes101
28. kesäkuuta 2010 klo 19:59 (GMT)
Um Hellooooooooooooo



NEW BLOG!!!
Member Since: 10.03.2010 Posts: 1 Comments: 7233
1206. MiamiHurricanes09
28. kesäkuuta 2010 klo 19:59 (GMT)
Why is everyone on this blog and not the more recent one?
Member Since: 2.09.2009 Posts: 130 Comments: 21032
1205. StormChaser81
28. kesäkuuta 2010 klo 19:58 (GMT)
Most storms when in a weak stage tend to sprawl outwards when loosing its spinning motion (angular momentum). Basically its a spinning top winding down, and has to get going again to pull all of that moisture back into the system.
Member Since: 11.08.2008 Posts: 0 Comments: 2315
1204. hurricanejunky
28. kesäkuuta 2010 klo 19:56 (GMT)
Quoting reedzone:
Wow, nice shift with the models.. Ya know what, it actually makes sense since Alex has been moving slow. Gotta go out now, bbl


Hey Reed, nice FORECASTS you did! Thanks!
Member Since: 28.08.2006 Posts: 6 Comments: 2895
1203. Progster
28. kesäkuuta 2010 klo 19:55 (GMT)
Link

Link to local neighbourhood buoy 42005.
Steady tendency ...slowly dropping p and slowly rising wind.
Member Since: 4.09.2007 Posts: 0 Comments: 490
1202. Baybuddy
28. kesäkuuta 2010 klo 19:54 (GMT)
Is anyone else having trouble sizing the page to their screen?
Member Since: 26.06.2006 Posts: 0 Comments: 1115
1201. StormChaser81
28. kesäkuuta 2010 klo 19:52 (GMT)
Quoting whs2012:


I think that Alex is about the same size as Ike...or will be once it can tighten itself up.


Also when it tightens, those outflow boundaries to the north east will cut off and it will get smaller looking.
Member Since: 11.08.2008 Posts: 0 Comments: 2315
1200. stillwaiting
28. kesäkuuta 2010 klo 19:52 (GMT)
the cloud pattern in the NE GOM is looking like a inverted trough of low pressure in the mid levels,I wonder if it could close off and work down to the surface???
Member Since: 5.10.2007 Posts: 20 Comments: 4970
1199. muddertracker
28. kesäkuuta 2010 klo 19:51 (GMT)
wow...nothing like a jfv/stormTOP sighting to clear out the blog! Remember: Have your trolls spayed or neutered!

Member Since: 16.08.2007 Posts: 1 Comments: 2316
1196. fsumet
28. kesäkuuta 2010 klo 19:48 (GMT)
The thing that bothers me about the model runs is looking at historical tracks like Hurricane Allen in 1980 and Bret in 1999, the ridge was much stronger than the one that is forecast. Plus those ridges didn't move like this one is going to. The models seem to keep this storm much weaker than it probably will be and as a much smaller storm. Is it going to turn as much as the models want, due west from a ridge in the central plains? I don't think so, but I guess we will see.
Member Since: 23.08.2006 Posts: 0 Comments: 164
1195. StormChaser81
28. kesäkuuta 2010 klo 19:45 (GMT)
Quoting RecordSeason:
Truly epic storm out there folks.

If it looks like it's coming your way, get ready to run is all I got to say.

It's gotta be deepening in some way or another to keep pulling in the entire EPAC like that.

It's starting to make Ike look average.


Epic storm, lol thats funny, its a decend sized tropical storm, watch as it spins up it will also tighten up and wont sprawl so far out.
Member Since: 11.08.2008 Posts: 0 Comments: 2315
1194. tropicfreak
28. kesäkuuta 2010 klo 19:45 (GMT)
wow, 5 minutes between post 1187 and 1188, thats a rarity considering this is masters blog and theres a TS soon to be hurricane threatening the US
Member Since: 2.09.2006 Posts: 110 Comments: 6814
1191. TexasRGV
28. kesäkuuta 2010 klo 19:40 (GMT)
I just left South Padre and arrived inland about 60 miles. Folks on the island are moving at about half the sense of urgency as they did for Dolly a mere 2 years ago.

Cameron County Judge (Brownsville) said on the radio this morning that they are monitoring this storm but for citizens to not panic because Alex doesn't pose near the threat that Dolly did in 2008 (? huh?)

All of South Texas and Northern Mexico experienced their wettest Spring in modern history....some places as much as 30 inches of precip since March. A slow heavy rain will absolutely devastate this area 10X worse than Dolly did following a 12-15 month drought.
Member Since: 23.07.2008 Posts: 0 Comments: 12
1189. tropicfreak
28. kesäkuuta 2010 klo 19:38 (GMT)
hello?????
Member Since: 2.09.2006 Posts: 110 Comments: 6814
1187. tropicfreak
28. kesäkuuta 2010 klo 19:33 (GMT)
Quoting StormTop5000:
I do have to say.. the moisture form Alex will stream into Texas from the Rio Grande to San Antonio.. and perhaps more into central and east Texas around Dallas to Texarkana later on, flooding will be a Big issue this week for Texas... You guys need to prep inland as well as coastal... Combined with a slow moving front/boundary over Texas, the rain will be unforgiving in the flood alley of the US....


Hold on.... wait is this stormTOP???
Member Since: 2.09.2006 Posts: 110 Comments: 6814
1185. ShenValleyFlyFish
28. kesäkuuta 2010 klo 19:31 (GMT)
Quoting Hardcoreweather2010:


Jim Cantorie is the storm shield and you want him to show up in your city cause you then know the storm will be deflected east or west of you . Jim has had one cane in his long career at TWC


Is he the shield or one damn good met who can figure out exactly where the storm wouldn't go but there is enough wind and rain to make dramatic video?

That's where I'd want to be if I had his job. Lol
Member Since: 9.09.2007 Posts: 36 Comments: 4687
1184. Skyepony (Mod)
28. kesäkuuta 2010 klo 19:30 (GMT)
Member Since: 10.08.2005 Posts: 156 Comments: 36105
1183. tropicfreak
28. kesäkuuta 2010 klo 19:30 (GMT)
Quoting whs2012:


If it hit around Corpus, would that still be a bad situation for us?


Yes it would, refer to post 1181.
Member Since: 2.09.2006 Posts: 110 Comments: 6814
1181. StormTop5000
28. kesäkuuta 2010 klo 19:27 (GMT)
I do have to say.. the moisture form Alex will stream into Texas from the Rio Grande to San Antonio.. and perhaps more into central and east Texas around Dallas to Texarkana later on, flooding will be a Big issue this week for Texas... You guys need to prep inland as well as coastal... Combined with a slow moving front/boundary over Texas, the rain will be unforgiving in the flood alley of the US....
Member Since: 15.05.2010 Posts: 0 Comments: 61
1180. Floodman
28. kesäkuuta 2010 klo 19:26 (GMT)
Quoting nash28:


If Alex could sing, this would be coming out of his "mouth."

"Wishcasters to the left of me.
Eastcasters to the right.
Here I am, stuck in weak steering flow too."


LMAO
Member Since: 2.08.2006 Posts: 10 Comments: 9922
1179. StormChaser81
28. kesäkuuta 2010 klo 19:26 (GMT)
Quoting Mia337:


At what point would you say SWLA is in the clear?


never, until its made landfall and dissipates. There unpredictable.
Member Since: 11.08.2008 Posts: 0 Comments: 2315
1178. HurricaneSwirl
28. kesäkuuta 2010 klo 19:25 (GMT)
Quoting winter123:

GFS trying to develop the wave coming off now. As a fish


Betcha that same trough that's trying to get Alex will get that one, or maybe the next trough in line on the west coast.
Member Since: 7.07.2008 Posts: 2 Comments: 3237
1177. tropicfreak
28. kesäkuuta 2010 klo 19:25 (GMT)
Quoting whs2012:


So if SWLA is in the clear, is Houston/Galveston in the clear too?


Not quite, but there is a low chance that it will hit houston, Galveston, ehh, well, we will just have to wait and see.
Member Since: 2.09.2006 Posts: 110 Comments: 6814
1176. NRAamy
28. kesäkuuta 2010 klo 19:23 (GMT)
1171. GoodOleBudSir 12:22 PM PDT on June 28, 2010
Quoting NRAamy:
1133. GlobalWarming 12:12 PM PDT on June 28, 2010
senior chief, god bless you for all that you do for us on here. you are tireless, sir.

don't you mean bud sir?





you called?




hahahahahahahahaha!

:)
Member Since: 24.01.2007 Posts: 316 Comments: 31944
1175. tropicfreak
28. kesäkuuta 2010 klo 19:22 (GMT)
Quoting Ameister12:

Jim is in Venice, LA.


TWC probably put him in the wrong spot, as they thought it would hit LA, what a big joke TWC is, can't track hurricanes correctly.
Member Since: 2.09.2006 Posts: 110 Comments: 6814
1173. Mia337
28. kesäkuuta 2010 klo 19:22 (GMT)
Thanks Storm
1172. hurricanehanna
28. kesäkuuta 2010 klo 19:22 (GMT)
Quoting StormW:


Now. If nothing chnages


YEAH!!!! {{hug}}
Member Since: 5.09.2007 Posts: 0 Comments: 3480
1171. GoodOleBudSir
28. kesäkuuta 2010 klo 19:22 (GMT)
Quoting NRAamy:
1133. GlobalWarming 12:12 PM PDT on June 28, 2010
senior chief, god bless you for all that you do for us on here. you are tireless, sir.


don't you mean bud sir?




you called?
Member Since: 30.07.2008 Posts: 0 Comments: 261
1170. ElConando
28. kesäkuuta 2010 klo 19:21 (GMT)
Quoting StormW:
Just a quick look at RGB loop...center has not relocated...in fact, shear has dropped about 5 kts from 20-15, and the convection is coming back over the center. Also appears to be drifting about 355-000, on close up shot


Wonder when it will get moving again.
Member Since: 6.09.2009 Posts: 2 Comments: 3709
1169. Kaydalenascar
28. kesäkuuta 2010 klo 19:21 (GMT)
New Blog is up!
Member Since: 27.06.2010 Posts: 0 Comments: 13
1167. weatherboyfsu
28. kesäkuuta 2010 klo 19:21 (GMT)
Ok...... Hey you can still see part of my video on Stormjunkie.com.... Its funny but awesome to have been there....

I will be back later....... peace
Member Since: 17.07.2005 Posts: 0 Comments: 1025
1166. WAHA
28. kesäkuuta 2010 klo 19:21 (GMT)

I really think something just broke off Alex. And according to the 850 millibar vorticity, it's rotating.
1165. hurricanehanna
28. kesäkuuta 2010 klo 19:20 (GMT)
Quoting nash28:


If Alex could sing, this would be coming out of his "mouth."

"Wishcasters to the left of me.
Eastcasters to the right.
Here I am, stuck in weak steering flow too."

priceless Nash :)
Member Since: 5.09.2007 Posts: 0 Comments: 3480

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About JeffMasters

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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