Alex continues to slowly organize

By: Dr. Jeff Masters , 7:17 PM GMT on June 28, 2010

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Tropical Storm Alex continues to slowly grow more organized as it steams away from Mexico's Yucatan Peninsula. Satellite loops show that Alex's heavy thunderstorms continue to increase in areal extent, and low level spirals bands are slowly building 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. Heavy thunderstorm activity is limited on the storm's northwest side, thanks to the shear and some dry continental air flowing off the coast of North America. Sea Surface Temperatures are very warm, 29°C. The latest Hurricane Hunter center fix, at 12:07 pm CDT, showed a central pressures of 990 mb, a 1 mb rise in six hours. Top winds were holding steady near 60 mph. Alex has stalled out the last few hours, as it began to "feel" the trough of low pressure to its north breaking down the high pressure ridge that has been pushing the storm to the west-northwest. This stall has allowed the storm to churn up cold water from the depths, which is probably interfering with development. Satellite loops show that Alex has a very large circulation covering about 2/3 of the Gulf of Mexico. We can expect that should Alex become a Category 2 or stronger hurricane, its storm surge will affect a much wider stretch of coast than Hurricane Dolly of 2008 did.


Figure 1. Afternoon satellite image of Alex.

Track forecast for Alex
The latest 12 UTC (7am CDT) runs of our most reliable computer models have come into much better agreement. 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 GFDN--is pretty much what NHC always uses as the basis of their forecast. This consensus forecast has narrowed in on the region just south of the Texas/Mexico border as being the most likely landfall location, with the usual cone of uncertainty surrounding it. The computer model that had been making the northernmost landfall predictions, the Canadian model, is now projecting a landfall 100 miles south of the Texas/Mexico border. There has been a general southward shift of the models in their latest runs, and the most northerly landfall location, near Port Mansfield, is now being predicted by the HWRF model. The earliest landfall time is Wednesday morning, and the latest is 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.

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. Forecast errors tend to be equally large along track (speed errors) and cross-track (deviations from side-to-side), so that means that about 20% 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 10am CDT (15 UTC) wind probability product predicted that Brownsville, Texas had the highest odds of getting a direct hit from Alex:

Brownsville, TX: 67% chance of tropical storm conditions (winds 39+ mph), 16% 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: 49% tropical storm, 6% hurricane.

Tampico, MX: 31% tropical storm, 4% hurricane.

Corpus Christi, TX: 45% tropical storm, 6% hurricane.

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

Galveston, TX: 21% 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.

Uncertainty in the NHC Cone of Uncertainty
A research project funded by NOAA known as the Joint Hurricane Testbed has produced a remarkable number of tools now in operational use at the National Hurricane Center to improve hurricane forecasts and warnings. One of these projects, called "Prediction of Consensus TC Track Forecast Error and Correctors to Improve Consensus TC Track Forecasts", was an effort by Dr. Jim Goerss at the Navy Research Lab to improve the accuracy of the NHC "cone of uncertainty" (AKA the "Cone of Death") showing where a storm is expected to track 2/3 of the time. The radius of the circles that make up the cone are based on error statistics of the official NHC forecast over the past five years. We can expect in certain situations, such as when the models are in substantial disagreement, a consensus forecast made using these models will have much greater than average errors. Since the NHC typically bases their forecast on a consensus forecast made using a combination of reliable hurricane forecasting models, it is instructive to view the "GPCE" (Goerss Prediction Consensus Error) circles to see if the uncertainty cone should be smaller or larger than usual. The consensus forecast I'll look at is called "TVCN", and is constructed by averaging the track forecasts made by most of (or all) of these models: GFS, ECMWF, NOGAPS, GFDL, HWRF, GFDN, and UKMET. In the case of this morning's 12 UTC (7am CDT) June 28 run of these models, here is what the radius of the "cone of uncertainty" should be, in nautical miles:

12 hours: 42 nm
24 hours: 73 nm
36 hours: 96 nm
48 hours: 112 nm
72 hours: 173 nm
96 hours: 327 nm
120 hours: 376 nm

And here is the radius of NHC's "cone of uncertainty" for their official forecast, based on the average errors for the past five years:

12 hours: 36 nm
24 hours: 62 nm
36 hours: 85 nm
48 hours: 108 nm
72 hours: 161 nm
96 hours: 220 nm
120 hours: 285 nm

So, the GPCE error estimates are showing that the latest forecasts for Alex out to 72 hours are 4% - 17% higher in uncertainty than average. The 4 - 5 day forecasts are 32% - 49% more uncertain than average--but of course, we expect Alex to be inland at those times.

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 a 78% chance of being a hurricane on Wednesday morning, and a 16% 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 has already stalled out once, and may stall out later in its path, as well. A stalled-out 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 enough roadblocks that I give a 20% chance of this happening.

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 southeast winds of 15 - 25 knots will blow over the oil slick region today through Wednesday, 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 video earlier this month showing the inside of the Haitian Presidential Palace during the mighty Haitian earthquake.

Next post
Dr. Rob Carver is planning on making a post late tonight, and I'll have an update by 9:30am CDT on Tuesday.

Jeff Masters

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Quoting Levi32:


No, but with a lot of these 0z runs coming in south of the TX/MX border, it may point towards less likelyhood of a Texas landfall, but that possibility is still very open. The models have been performing terribly so far even in the short term track.

So do you think we still need to watch this here in SW LA?
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look at the orange CLP5 29/0000Z model on this map. it shows the the same path that Hurricane Audrey took in 1957. also look Very Closely at how all the models thats together over texas take a sharp curve to the northeast like Hurricane Audrey did in 1957.
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Quoting CaneAddict:
Tropical Storm/Hurricane Alex is strengthening at a good rate..becoming very well organized. 2AM I'd expect them to upgrade Alex to an 80MPH Category One hurricane. JMO


I agree!
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If this turns out to be Audrey, then every model & forcaster including the NHC & Joe B were wrong.
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3003. Levi32
Quoting Joanie38:
So is this track set in stone now??


No, but with a lot of these 0z runs coming in south of the TX/MX border, it may point towards less likelyhood of a Texas landfall, but that possibility is still very open. The models have been performing terribly so far even in the short term track.
Member Since: November 24, 2005 Posts: 628 Comments: 26455
Tropical Storm/Hurricane Alex is strengthening at a good rate..becoming very well organized. 2AM I'd expect them to upgrade Alex to an 80MPH Category One hurricane. JMO
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So is this track set in stone now??
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Quoting LightningCharmer:


Would be a pretty quiet blog after one storm. There might be four maybe five posters remaining. LOL


Should be something to filter out all the "ZOMG! its going to hit NO as a cat 5!!!!!!!!elevnty!!! bank on it!!!!" stuff that's been around so much. Then again, it's like that every season. A few names you come to listen to, a whole lot of other background noise.
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2999. Levi32
985.8mb as they narrow down the center. It will likely be a few tenths lower in the next set of obs.

000
URNT15 KNHC 290524
AF304 0701A ALEX HDOB 53 20100629
051500 2056N 09203W 9245 00645 9952 211 202 277029 030 031 001 03
051530 2057N 09202W 9245 00643 9950 211 201 278028 029 031 001 03
051600 2058N 09201W 9248 00638 9947 209 201 280027 028 031 001 00
051630 2100N 09200W 9245 00636 9944 208 201 278029 030 031 001 00
051700 2101N 09159W 9252 00627 9940 210 200 275029 030 030 001 00
051730 2103N 09159W 9250 00627 9936 211 200 277028 029 031 002 03
051800 2104N 09158W 9246 00625 9932 211 201 283026 027 031 000 00
051830 2106N 09158W 9246 00622 9927 215 202 284027 028 032 000 00
051900 2107N 09158W 9251 00613 9923 215 203 291027 028 032 002 00
051930 2109N 09157W 9252 00609 9919 214 205 299029 031 033 002 03
052000 2110N 09157W 9248 00609 9910 225 206 295031 032 036 000 00
052030 2111N 09156W 9249 00601 9902 235 208 300032 033 036 002 00
052100 2113N 09155W 9244 00600 9896 228 210 304033 035 037 000 00
052130 2114N 09155W 9254 00586 9892 222 213 302032 032 037 002 00
052200 2115N 09154W 9247 00588 9885 235 215 309031 032 037 001 00
052230 2117N 09153W 9244 00586 9880 230 216 316028 030 034 001 00
052300 2118N 09152W 9244 00580 9873 231 218 318024 026 032 001 00
052330 2119N 09151W 9245 00574 9868 228 219 310017 019 026 000 03
052400 2120N 09150W 9245 00570 9863 231 220 302015 015 024 000 00
052430 2121N 09149W 9244 00567 9858 232 221 296013 014 022 000 03
$$
Member Since: November 24, 2005 Posts: 628 Comments: 26455
Good thing LA is IN THE CLEAR!!!
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Quoting gustavcane:
hi all its been awhile since I have posted on wunderground, but I have been reading all of the posts here everyday. this storm is in a very close coordinate postion as Hurricane Audrey when it formed on the same month and day as Tropical Storm Alex did. Hurricane Audrey formed on June 25, 1957 and Tropical Storm Alex formed on June 25, 2010. this storm is now drifting north at 4 mph just like Hurricane Audrey did in 1957.


SmileyCentral.com
Gus! Stop that! ;)
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2996. xcool


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Quoting LightningCharmer:


Would be a pretty quiet blog after one storm. There might be four maybe five posters remaining. LOL


That many, sounds a bit liberal.
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Quoting BA:
here's an idea...

new blog policy: if you make a landfall prediction and you are wrong, you get banned for life

I bet that would cut down on some of the crazy predictions people make. :)


Would be a pretty quiet blog after one storm. There might be four maybe five posters remaining. LOL
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Quoting Levi32:


I agree....how many people actually use the math proofs again unless they are numerical computer modelers. I would like to actually send up weather balloons and do forecasting activities so that I can learn how to do actually do a job in that field.


I agree. In fact, I once heard StormW say that he doesn't use a "lick of math" in his forecasting. Obviously, this was hyperbolic, but he basically meant that he only uses basic mathematics in his forecasting. It's exactly the same for me.

It's as you said, really. One does not need to know a whole lot of advanced mathematics unless they desire to be a computer modeler or something like that.
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2992. xcool
/ecmwf in 45min
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Quoting BA:
here's an idea...

new blog policy: if you make a landfall prediction and you are wrong, you get banned for life

I bet that would cut down on some of the crazy predictions people make. :)
Quoting BA:
here's an idea...

new blog policy: if you make a landfall prediction and you are wrong, you get banned for life

I bet that would cut down on some of the crazy predictions people make. :)


I'm thinkin a direct hit at BA's house.
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Quoting LightningCharmer:


I don't know if I agree with the new format. Math is only 1/3 of the total score and verbal, reading and writing, 2/3's. Are language skills twice as important as math skills. Would we have had such a mortgage crisis if more understood math, i.e. finance, better?

Not that language skill are not important but math based fields like accounting, engineering, computers, tele-communications, manufacturing, pharmaceuticals, weather forcasting, etc. are generally more wealth producing and provide scientific advances that lead to among other things, more advance warning of pending severe weather including tropical weather events.

Maybe they, the powers that be, added the writing because of the all the "Text-Speak." (Not while driving Oprah)


I agree about the math. I would encourage anyone to pay attention to the math if you want a good high paying job. Seems like those jobs were looking for employees as others were closing their doors. A sign of the times.
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2987. Levi32
Quoting Headindaclouds:


You will do great Levi! A college degree is really just a ticket of admission rather than practical knowledge. The only thing I really learned in college was that I really don't know very much at all.

:)


Haha so true. It should be a good experience for me though.
Member Since: November 24, 2005 Posts: 628 Comments: 26455
2986. Gorty
Sorry, foroght the link:

Link
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2985. BA
here's an idea...

new blog policy: if you make a landfall prediction and you are wrong, you get banned for life

I bet that would cut down on some of the crazy predictions people make. :)
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2984. Levi32
Quoting Hurricanman:


I'm getting plenty of updates here:
http://www.esl.lsu.edu/animate/goes/index.php?region=gulf&channel=ir


Forgot about that one thanks. It stays in rapid-scan when the others don't. Too bad it doesn't have enhanced colors.
Member Since: November 24, 2005 Posts: 628 Comments: 26455
Quoting Levi32:


I agree....how many people actually use the math proofs again unless they are numerical computer modelers. I would like to actually send up weather balloons and do forecasting activities so that I can learn how to do actually do a job in that field.


You will do great Levi! A college degree is really just a ticket of admission rather than practical knowledge. The only thing I really learned in college was that I really don't know very much at all.

:)
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Quoting HoustonTxGal:
Can someone tell me where I can find the new models please?


Post 2907. I think they're new.
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Quoting homelesswanderer:


Oh ok. They must have added a section. We had verbal and math. 800 each. I knew something was diferent tho.


I don't know if I agree with the new format. Math is only 1/3 of the total score and verbal, reading and writing, 2/3's. Are language skills twice as important as math skills. Would we have had such a mortgage crisis if more understood math, i.e. finance, better?

Not that language skill are not important but math based fields like accounting, engineering, computers, tele-communications, manufacturing, pharmaceuticals, weather forcasting, etc. are generally more wealth producing and provide scientific advances that lead to among other things, more advance warning of pending severe weather including tropical weather events.

Maybe they, the powers that be, added the writing because of the all the "Text-Speak." (Not while driving Oprah)

Perhaps maybe it goes back to our learnin' roots, "readin', writin' & 'rithmatic.
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Still seeing due N movement?

Link

Forget it, it's past 1 and I'll just look again when I get up. I still hold ever since it started moving NNW in the gulf that it would make landfall way north of expected.
Member Since: July 29, 2006 Posts: 28 Comments: 1762
hi all its been awhile since I have posted on wunderground, but I have been reading all of the posts here everyday. this storm is in a very close coordinate postion as Hurricane Audrey when it formed on the same month and day as Tropical Storm Alex did. Hurricane Audrey formed on June 25, 1957 and Tropical Storm Alex formed on June 25, 2010. this storm is now drifting north at 4 mph just like Hurricane Audrey did in 1957.
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Quoting Levi32:


Hm ya I guess so lol....I also hear that Met/Atmospheric Science classes back then had a lot more hands-on application of concepts, and less math proofs and technical data without as much application, like it is now.


Yeah. Computers changed a lot of things. I agree the old way had more practical experience. Now you have to learn that along side the running of the computers. They've taken the fun out some things. But added fun to others.
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Can someone tell me where I can find the new models please?
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Quoting Levi32:
The fast-updating satellite sites are having issues tonight...but I'm managing to get an image out once in a while


I'm getting plenty of updates here:
http://www.esl.lsu.edu/animate/goes/index.php?region=gulf&channel=ir
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2974. xcool
:0
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I guess its set in stone now eh??
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2972. Gorty
A quick update on Alex mainly with his track and intensity:

http://www.wunderground.com/blog/Gorty/show.html
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Quoting Levi32:
The fast-updating satellite sites are having issues tonight...but I'm managing to get an image out once in a while.

04:45 shows cloud tops warming with a few new cells going up on the east side.



Yeah, my server has been e-mailing me all night saying the images have been the same when it fetches it from the GHCC site. It's probably just undergoing maintenance.
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2969. help4u
hwrf to texas. 00z
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2968. xcool
I'M BACK I WAS BLOG ON NEW WEBSITE
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2967. Levi32
Quoting KoritheMan:


I wonder why they changed it, then? Seems fine the way it was, if you ask me...


I agree....how many people actually use the math proofs again unless they are numerical computer modelers. I would like to actually send up weather balloons and do forecasting activities so that I can learn how to do actually do a job in that field.
Member Since: November 24, 2005 Posts: 628 Comments: 26455
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Here is a pretty nice image
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2962. Daveg
Models are definitely clustering more north of the border, but they've done that a couple of times today, so we'll see if they stay there.

Going to be somewhere near Brownsville or slightly north if they stay this way though.

I don't see LA getting anywhere near the action however.
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Quoting Levi32:


Hm ya I guess so lol....I also hear that Met/Atmospheric Science classes back then had a lot more hands-on application of concepts, and less math proofs and technical data without as much application, like it is now.


I wonder why they changed it, then? Seems fine the way it was, if you ask me...
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hey btwntx08.....Baytown?
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2942:That is a cool picture
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2958. Levi32
The fast-updating satellite sites are having issues tonight...but I'm managing to get an image out once in a while.

04:45 shows cloud tops warming with a few new cells going up on the east side.

Member Since: November 24, 2005 Posts: 628 Comments: 26455
2957. xcool
from TX TO SW LA I KNOW KEEP SAY I KNOW KEEP SAY IF WRONG KABOOM ME.
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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.