Large and intensifying Hurricane Alex bears down on northeastern Mexico, South Texas

By: Dr. Jeff Masters , 2:23 PM GMT on June 30, 2010

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Hurricane Alex continues to intensify as it slowly bears down on the coast of northeastern Mexico. Brownsville long-range radar shows the spiral bands of Alex, which has dumped heavy rains of up to four inches in northeastern Mexico and near Brownsville, according to satellite estimates of rainfall. The Brownsville airport received 0.78" of rain in the hour ending at 8am CDT, and 0.61" in the hour ending at 9am CDT. Floods from Alex have already killed ten people--six in Nicaragua, and two each in El Salvador and Guatemala.


Figure 1. Snapshot of the Brownsville long-range radar showing Hurricane Alex approaching the coast.

The 7:12am CDT eye penetration of the Hurricane Hunters found a central pressure of 959 mb, a modest 2 mb drop from the reading four hours previous to that. They noted a very tiny eye, ten miles in diameter, with a gap in the northwest side. Tiny eyes like this tend to be unstable, and in the 9:05am CDT eye penetration, the Hurricane Hunters found that the inner eyewall had collapsed, and the pressure had risen 2 mb, to 961 mb. A new, much larger eye will form today as the day progresses. During these "eyewall replacement cycles", a hurricane will typically weaken a few millibars , and the strongest winds will spread out over a larger area as the hurricane conserves angular momentum. Thus, the hurricane still has about the same amount of destructive power, it is just spread out over a larger area. This tends to increase the hurricane's storm surge, but lessens the wind damage, since the extreme winds of the inner eyewall are no longer present. Satellite loops show a large, well-organized storm with increasing amounts of low-level spiral bands forming, and improving upper-level outflow. Data from last night's flight of the NOAA jet showed an unusually moist atmosphere surrounds Alex, so dry air is no longer a problem for it. It's a good thing Alex has less than a day before making landfall, or else is would be a large and very powerful major hurricane.


Figure 2. Visible light image of Tropical Storm Alex taken at 19:35 UTC (2:35 pm CDT) on June 29, 2010, by NASA's Aqua satellite. At the time, Alex was a tropical storm with 70 mph winds. Image credit: NASA.

Storm Surge
Traditionally, a storm's ranking on the Saffir-Simpson Scale--the familiar Category 1, 2, 3, 4, 5 rankings we always talk about--have also been used to quantify storm surge threat. However, large, weaker storms that cover a huge area of the Gulf of Mexico, like Alex, can generate a larger storm surge than a smaller but more intense hurricane with a higher Saffir-Simpson rating. Thus, the National Hurricane Center has formally discontinued use of the Saffir-Simpson scale to characterize storm surge, and is studying the possibility of issuing separate Storm Surge Warnings a few years from now. These would be in addition to their traditional Hurricane Warnings. To give us a better idea of a storm's surge potential, Dr. Mark Powell of NOAA's Hurricane Research Division has developed the Integrated Kinetic Energy scale to rank storms. The scale ranges from 0 to 6, and a parallel wind damage scale that runs from 0 to 6 is also generated. Alex had an Integrated Kinetic Energy of 2.6 on the 0 to 6 scale at 1:30pm CDT yesterday, and its destructive potential rating for winds was just 1.2. Thus, Alex's surge ranked alomst one-and-a-half categories higher in destructive potential than its wind. These numbers have probably increased by a full category since yesterday afternoon. NHC is giving a 40% - 60% chance of a storm surge of at least 3 feet affecting the Brownsville area, and 10% - 30% chance the surge will exceed 5 feet. In theory, a Category 2 hurricane moving WNW at 5 mph can bring a storm surge of up to 8 - 9 feet to the South Texas and northern Mexican coast.

Other Impacts
Alex is bringing bands of heavy rain to the coasts of Texas and Mexico, as seen on the Brownsville, Texas radar. Hurricane local statements with projections for how Alex will affect the coast are now being issued by the National Weather Service in Brownsville and Corpus Christi. Flooding damage from the expected 6 - 12 inches of rain from Alex will be the main concern. Wind damage is a lesser concern, since the core of Alex is making landfall in a swampy, sparsely populated region of Mexico. The combined wind, surge, and flooding damage from Alex may be similar to 2008's Hurricane Dolly, which hit near Brownsville. Dolly was a Category 2 hurricane offshore that weakened to a Category 1 hurricane with 85 mph winds when it made landfall, and did about $1 billion in damage. Dolly also generated two weak EF-0 tornadoes, and Alex is capable of generating a few tornadoes as well, according to the latest discussion from NOAA's Storm Prediction Center. The atmosphere is moderately unstable, there is plenty of moisture, and wind shear at low levels has been increasing this morning. The greatest threat for tornadoes will occur late this afternoon, on the right side of where the storm makes landfall.

Alex in historical context
Alex is the first June hurricane since Hurricane Allison of 1995. Allison briefly became a minimal 75 mph hurricane before weakening and hitting the Florida Panhandle as a tropical storm. Alex is the strongest June hurricane since Hurricane Bonnie of 1986, which had 85 mph winds. Bonnie was the first hurricane I flew into as a member of the Hurricane Hunters. Bonnie made landfall along the upper Texas coast, and caused less than $20 million in damage. If Alex strengthens to 90 mph winds, it will be the strongest June hurricane since Hurricane Alma of 1966, which had 125 mph winds as it skirted the Florida Keys. There have been only ten hurricanes in May or June since 1945; only four of these were major Category 3 or higher storms.

Track forecast for Alex
All of the models take Alex to the west or west-northwest into northern Mexico by early Thursday morning. However, the steering currents are fairly weak, and Alex could stall and move erratically at times today. I don't anticipate that this weakness in the steering currents will allow Alex to move northward and make landfall in Texas. After landfall, the ridge of high pressure forcing Alex westward should remain in place and strengthen, keeping Alex's remnants over northern Mexico for several days.

Intensity forecast for Alex
Alex is over a region of ocean with moderately high total ocean heat content . Wind shear has fallen to a low 5 knots, and is projected by the SHIPS model to remain in the low range, below 10 knots, through landfall. The combination of low wind shear, moderately high ocean heat content, and plenty of moisture should allow Alex to continue to intensify today. Alex's pressure is already characteristic of a Category 3 hurricane, but the storm is so large that it is taking time for the winds to catch up to the pressure falls. It is unlikely that Alex's winds will be at Category 3 strength at landfall, since the storm is undergoing an eyewall replacement cycle, and does not have time to build a tight inner eyewall with strong winds before landfall. A Category 2 storm at landfall looks more likely.

Elsewhere in the tropics
The latest run of the NOGAPS model predicts the formation of a tropical disturbance in the Western Caribbean on Monday. None of the other models is showing anything brewing over the coming seven days.

Wind and ocean current forecast for the BP oil disaster
Alex is generating very rough conditions over the Deepwater Horizon blowout location, with 6 - 8 foot waves and 3 - 4 foot swells. Strong southeast to south winds of 15 - 25 knots will blow over the oil slick region today through Thursday, according to the latest marine forecast from NOAA. The resulting currents will push oil to many protected bays and estuaries that haven't seen oil yet. In addition, the 1 - 2 foot storm surge Alex is generating along the Louisiana coast will act to push oil deep into some low-lying marshlands. While this oil will be diluted some by the wave action, the impact of the oil and accompanying toxic dispersants on the marshlands is of concern. The latest trajectory forecasts from NOAA and the State of Louisiana show oil will also move westward along the central Louisiana coast towards the Texas border. Winds will decrease to 10 - 15 knots Friday through Monday but remain out of the southeast, keeping the pressure on the regions of coast in Louisiana, Alabama, and Mississippi that are seeing oil hit their shores this week.

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

Next post
Either Rob Carver or myself will do an update late this afternoon or this evening.

Jeff Masters

Hurricane Alex (LRandyB)
Weather inbound to Hurricane Alex.
Hurricane Alex
Hurricane Alex (LRandyB)
Weather inbound to Hurricane Alex.
Hurricane Alex
Hurricane Alex (LRandyB)
Flight deck view from a WC-130J Hurricane Hunter aircraft
Hurricane Alex

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Quoting JFLORIDA:


lol famous last words.

Come on if something like Charley were to go in there and you waited to the last minute you'd drown in your car along with everyone there and in st pete too. You know that CW! Tampa is FLAT.


I know, but I know how to monitor the water levels. I'd leave before it got too bad.
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Looks like a dome eyewall to me, also notice the small eye beginning to clear out.

Member Since: September 2, 2009 Posts: 130 Comments: 21091
Quoting PensacolaDoug:
Same with IVAN. Came in at 130 am or so.


And Ivan was a slow mover with a huge radius of winds. He roared, and roared, and roared some more.
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Quoting weatherboyfsu:
Power was out throughout most of Orlando..... Red lights were a nightmare.... It was hot and muggy with no power for a week in many areas. No drinking water either and this was in Orlando..... Almost 200 miles from the actual landfall.


The forward speed is what caused problems. I think he was moving between 24-28 mph. By the time he hit cat 1 he was all the way across FL.
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765. PensacolaDoug 10:15 AM PDT on June 30, 2010
Wheres Oz?
Where's Cantore?
Where's Waldo?em>


hahahahahahahaha!
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Heavy bands moving into Brownsville

Member Since: October 28, 2006 Posts: 57 Comments: 29886
Quoting Hurricanes101:
I have always said for those who do not think Hurricanes can have a great impact inland; 2 prime examples

Hugo and what it did to Charlotte back in 1989

Charley and what it did to Orlando back in 2004

just because you live inland, does not mean you should not be prepared

Not to mention what Ike did to the Ohio Valley!
Member Since: August 2, 2006 Posts: 46 Comments: 11665
Quoting StSimonsIslandGAGuy:
How was Orlando during and after Charley?


I think there was a wind gust to 105. Trees were down and there was no power. The place I stayed lost a couple of windows and every single shingle on the roof was gone.
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Quoting Drakoen:
Recon closing in on the eye
Great!
Member Since: September 2, 2009 Posts: 130 Comments: 21091
im one of the viewers...lol...so it sounds like oz is giving up trying to get into mexico...i guess he will be staying in the south padre/ state highway 4 area while alex comes in...
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Quoting AstroHurricane001:


The original wave over Africa that we were watching was partially absorbed into the ICTZ, and now another wave is coming behind it, entering the water and absorbing part of the earlier wave. However, is that a circulation I see just E of Cape Verde?

Hi Astro,
I think the Low is west of the wave we are seeing.
...TROPICAL WAVES... (From the 8 a.m. NHC Discussion)

TROPICAL WAVE EXTENDS FROM 05N26W TO 17N25W MOVING W AT 15-20 KT. THE WAVE LIES WEST OF THE LEADING EDGE OF A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY.
CYCLONIC CURVATURE IS ALSO NOTED ON SATELLITE IMAGERY ABOUT THE WAVE AXIS IN THE LOW-LEVEL CLOUD FIELD BETWEEN 23W-30W. ISOLATED MODERATE CONVECTION IS FROM 02N-11N BETWEEN 23W-30W.
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Member Since: June 9, 2007 Posts: 4 Comments: 15776
Recon closing in on the eye
Member Since: October 28, 2006 Posts: 57 Comments: 29886
Quoting homelesswanderer:


I'd have to agree. My area seems to attract night crawlers. Rita, Ike and Humberto all made landfall at roughly 2 a.m. Heck even Edouard came slinking by in the wee hours. As horrific as Rita and Ike were, the one you have no idea is coming is pretty scary too. I still didn't know much about hurricanes when Humberto came screaming and screeching by. Won't another one sneak up on me again. :)

I was very upset that both Rita and Ike came in at night. My hurricane footage suffered because of it.
Member Since: August 2, 2006 Posts: 46 Comments: 11665
Quoting Hurricanes101:
I have always said for those who do not think Hurricanes can have a great impact inland; 2 prime examples

Hugo and what it did to Charlotte back in 1989

Charley and what it did to Orlando back in 2004

just because you live inland, does not mean you should not be prepared


Exactly...
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Quoting CaneWarning:


I wish I had stayed put. Next time I'm not leaving Tampa until the last minute. I just have to make it over the bridge off the island before things flood.
It's always better to be safe than sorry though.
Member Since: August 12, 2009 Posts: 0 Comments: 203
781. xcool
flight
Member Since: September 26, 2009 Posts: 2 Comments: 15620
650. That is an amazing picture.
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Power was out throughout most of Orlando..... Red lights were a nightmare.... It was hot and muggy with no power for a week in many areas. No drinking water either and this was in Orlando..... Almost 200 miles from the actual landfall.
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I have always said for those who do not think Hurricanes can have a great impact inland; 2 prime examples

Hugo and what it did to Charlotte back in 1989

Charley and what it did to Orlando back in 2004

just because you live inland, does not mean you should not be prepared
Member Since: March 10, 2010 Posts: 1 Comments: 7361
Same with IVAN. Came in at 130 am or so.
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Quoting xcool:
Inactivity recon report


Surface or flight level winds.
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Quoting PensacolaDoug:
Oz has 217 viewers right now!

www.7674u.com


I'm one of them.
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Quoting PensacolaDoug:
Oz has 217 viewers right now!

www.7674u.com

tell him that the storm track shift slightly more north, he thinks it is more south.
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Quoting msglfcst:


Landfall at night makes it more anxiety producing. Camille was worse for my area due to a landfall during night; compared to Katrina who landed during the day. Just my opinion.


I'd have to agree. My area seems to attract night crawlers. Rita, Ike and Humberto all made landfall at roughly 2 a.m. Heck even Edouard came slinking by in the wee hours. As horrific as Rita and Ike were, the one you have no idea is coming is pretty scary too. I still didn't know much about hurricanes when Humberto came screaming and screeching by. Won't another one sneak up on me again. :)
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Interesting to note how many servings of crow are likely to be returned to those who sent them yesterday. ;-D
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Quoting StSimonsIslandGAGuy:
How was Orlando during and after Charley?


about as bad as you can expect considering Orlando is about 50 miles inland

Member Since: March 10, 2010 Posts: 1 Comments: 7361
Quoting StSimonsIslandGAGuy:
How was Orlando during and after Charley?


During charley things were flying everywhere and after it was a huge city in the dark.
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Wheres Oz?
Where's Cantore?
Where's Waldo?
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Here is NW Houston, it is muggy, but we have had very little rain.
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i can not stand the big headed folk on here posting their opinion like its coming from the nhc...like the post i was referring to...
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760. xcool
Inactivity recon report
Member Since: September 26, 2009 Posts: 2 Comments: 15620
NEXRAD Radar
Brownsville, Storm Relative Mean Radial Velocity 1.45 Degree Elevation Range 124 NMI


Member Since: July 3, 2005 Posts: 420 Comments: 127541
Oz has 217 viewers right now!

www.7674u.com
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Quoting DestinJeff:
COC is nearly due east of 0600Z TFP (prog'd landfall)
Yes, due east of "La Pesca" Mexico.
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Quoting TankHead93:
And my family and I stayed put... not even a drop of rain here in St. Petersburg that day... HOORAY!


I wish I had stayed put. Next time I'm not leaving Tampa until the last minute. I just have to make it over the bridge off the island before things flood.
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Quoting weatherboyfsu:
I went thru Charley here in Orlando..... Couldnt make it to the coast because of the uncertainty of where he was going to make landfall. Charley was still a formidable storm in Orlando. We had wind gust over 100 mph at the Orlando Executive Airport.


I was at WFTV channel 9 in Downtown Orlando running severe weather warnings. It was a very impressive storm. The airport had a wind gust of 105mph.
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754. IMA
Quoting earthlydragonfly:

I am a florida employer of over 1000 employees. Go to your boss and talk... Dont demand, cooler minds will prevail.. If you are in a flood plain, tell your boss and explain your situation. He may live in high and dry area and that prospect has not crossed his mind. I happen to be very sensitive to the tropics since I love weather. But he or she may not and have no idea what you case may be.

Also, folks lets all keep this storm in perspective at least for now it is not even a cat 2 so lets keep things grounded a bit. This should not be a major wind event or even a major surge event unless your right on the coast. Flooding could be the big factor so you should know what and where the flood plains in your area are.

Calm heads have a much better chance of making a good well thought out descision then shooting from the hip and giving your boss notice because you didnt talk it out.

My 2 cents

I am not the one with the issue, I was referring to the person in Matamoros, and I certainly didn't say I would "demand" or give notice! Also, I specifically said that flooding was my concern for this person, not surge or wind. Of course, wind from Alex could still wreak havoc there. The building codes are quite different from what you find in the U.S.; however, let me state again that my concern is flooding. Matamoros is 33ft above sea level and sits between the river & the Gulf. Go take a look on Google Maps, using the satellite view, and you'll see why I'm concerned for this person.
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Quoting xcool:
95MPH WIND NOWWW


Person 1:Oh really

Person 2:How do you know
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Quoting hurrkat05:
scott the deepening trough at the 750mb level is in the the southwest fixing to dive southeast in the next 36 hours..if alex continues to intensify we are going to have major problems with his current track...i expect the to shift to the right later this evening..the nhc has its hands full they are going to have to make the change no way this is going into mexico or southern texas directly...
It looks like its moving faster and torward the coast MX/TX boarder. It looks like it will make landfall before 36 hours!
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LOL "Im an ex-military man, and I cuss like a sailor".

had to do his whole coverage over cause of some, er, ah, creative word usage.
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Quoting Chicklit:
Hey, good afternoon. Is Cantore there yet?
Don't want to change the subject. Just want to keep you all up to date on what's happenen' further east. IRLoop

Meteostat


The original wave over Africa that we were watching was partially absorbed into the ICTZ, and now another wave is coming behind it, entering the water and absorbing part of the earlier wave. However, is that a circulation I see just E of Cape Verde?
Member Since: August 30, 2008 Posts: 8 Comments: 2835
Quoting 1900hurricane:

If you think you've got high PWs, check out the PWs from Alex in Brownsville! Ever seen 3" PWs before?







holy crap!

Yeah well that's because a dang tropical cyclone is moving in!


To show you how much rain can be released in that kind of moisture level, we had a rainfall rate here of 12 inches per hour during a really intense squall during hurricane Frances. Of course those squalls only last about 5 minutes or so, but that's plenty long enough to cause flooding when it rains that heavy, it was raining so hard, it felt like entire swimming pools were being dumped on me and my and my area at a constant rate lol
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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.

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