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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Thanks weatherboyfsu!
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canewarning.....
That would make me nervous not knowing how your home is doing while you are gone... :(


Although, I live next to the everglades....almost like living next to the ocean....maybe they should evacute us too? lol-j/k
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Quoting Unfriendly:
Oz just turned around to grab a water moccasin. and put it in his car.


LOL... I wonder if he's had anything to drink.
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Pretty heavy squall moving through Panama City right now. I was so busy watching Alex, I missed my own radar warning and had to run out in the down pour to turn off the pool.
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Member Since: June 9, 2007 Posts: 4 Comments: 15950
Oz just turned around to grab a water moccasin. and put it in his car.
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We will be able to follow the 1km radar all the way to landfall now, just coming into view.

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Quoting GBguy88:
Does this feel like a mid-season storm to anyone else? Maybe it's just me, but it sure feels weird to be watching a storm like this in June. I was skeptical about all the increased forecasts for this year, but starting to put a little more stock into them now. Could be an odd year.


It is amazing to see a storm like this in June, especially one coming into the coast without being sheared. It is very mature for a June storm.
Member Since: November 24, 2005 Posts: 635 Comments: 26701
Anyone think that Alex may make this list?

List of the Wettest Tropical Cyclones in Texas
Member Since: August 2, 2006 Posts: 47 Comments: 11709
So, is Alex really moving a little northerly? Right now, when you look at the satellite, it looks like Alex will visit Brownsville or am I being deceived?
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For everyone in TX and mexico, stay safe.
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859...
Neat link Pat.
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Quoting Chicklit:
Looks like landfall may be around midnight tonight.

852: They need to issue interim updates of these maps when they are so clearly busted this close to landfall in a populous area.
Member Since: August 17, 2009 Posts: 0 Comments: 579
Hi Patrap! How's in ur parts of nola? Winds are pickingup here in Baton Rouge and rain just started. i feel a nap coming on
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Quoting MiamiHurricanes09:
It also shows another tropical wave becoming a TS and hitting Florida.


Error: website blocked.
Member Since: August 30, 2008 Posts: 8 Comments: 2836
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Depending on the future track of Alex one of the most dangerous situations may be developing in Monterrey MX. Monterrey is the third most populous city in Mexico with well over 1 million residents. It sits at the foothills of the Sierra Madre Oriental that tower up to a mile high above the city. The Santa Catarina River—dry most of the year—bisects the city.

The great 1909 Monterrey hurricane made its final landfall in the Mexican state of Tamaulipas on August 27 of that year, then proceeded to cause inland flash flooding that killed over 4000 in Mexico. In Monterrey the Santa Catarina River rose well over its banks, destroying hundreds of homes and leaving an estimated 20,000 people homeless.
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Does this feel like a mid-season storm to anyone else? Maybe it's just me, but it sure feels weird to be watching a storm like this in June. I was skeptical about all the increased forecasts for this year, but starting to put a little more stock into them now. Could be an odd year.
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Quoting connie1976:
...hey all...

Do you get your hurricane supplies when hurricane season starts or when one threatens your area?

What do you usually get?



I wait until a storm is threatening my area. I always have to evacuate though, so I don't need much.
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Quoting NRAamy:
hey Jerry!


Amy! How are you today, darlin'?
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869. connie1976 5:34 PM GMT on June 30, 2010
...hey all...

Do you get your hurricane supplies when hurricane season starts or when one threatens your area?

What do you usually get
Get a lot of can goods and bottled water. You can go to any of your local TV websites and they have all the info for you there.
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I saw the strangest thing yesterday at Mullet Point (eastern shore mobile bay) it was raining and the droplets of rainwater floated on the surface of the bay for about five seconds before being absorbed. There was no visible sheen...must have been there though.
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Afternoon, it appears alex is moving more due NNW than it was earlier. I expect a TX/Mexico border landfall.
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Quoting IKE:
12Z NOGAPS shows a northern GOM vorticity and another system heading up through the Yucatan channel....


Yuck! ECMWF keeps showing things off and on. May have some development sooner than people think. So far it's been a weird season. Why not.
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12z models taking Alex far enough south that Brownsville would not see hurricane force sustained winds. Maybe gusts...
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Quoting Patrap:






The storm was in 05,,the Graphic is used as a example to the New,well started in 2009 Hurricane Inland Wind Warning that the Storms,Ike,Rita,K and Gustav spurned.

Its one the NOAA/NHC site which I encourage all to read.


The inland wind warnings predate Rita. I remember being in inland tropical storm wind warnings for TS. Fay in 2002, I believe.
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...hey all...

Do you get your hurricane supplies when hurricane season starts or when one threatens your area?

What do you usually get?

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Quoting ShenValleyFlyFish:
2' h20 moving with that kind of force will knock anybody's @&& over. Why so many die in flash floods.


Was more of a joke. I am well aware about storm surge though, my area is not at great risk for any storm surge.
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Quoting ShenValleyFlyFish:
2' h20 moving with that kind of force will knock anybody's @&& over. Why so many die in flash floods.


the rule is 6"s is enough to wash ur car away.
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Member Since: June 9, 2007 Posts: 4 Comments: 15950
Quoting houstongator:

I was in Atlanta in 1995 when Opal came through and we had 70 MPH gusts and tons of damage... Atlanta... Georgia... Please stay prepared everyone.

I was in Hugo in BLACKSBURG VA
400 or so miles of inland track and it TRASHED us up in the mountains there.. forests looked like god was playing pick up sticks..had huge trees falling all around me...crazy
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Quoting IKE:
12Z NOGAPS shows a northern GOM vorticity and another system heading up through the Yucatan channel....
It also shows another tropical wave becoming a TS and hitting Florida.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Eye finally visible on satellite imagery, pressure slightly up due to the double eyewall, but winds are rising too.
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Click me too!

^Storm surge map^
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Quoting Drakoen:


9-12 hours away




Thank-you
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Quoting winter123:

That makes a lot more sense. This was made in 2005? Why hasn't it been implemented yet??


The storm was in 05,,the Graphic is used as a example to the New,well started in 2009 Hurricane Inland Wind Warning that the Storms,Ike,Rita,K and Gustav spurned.

Its on the NOAA/NHC site which I encourage all to read.
Member Since: July 3, 2005 Posts: 428 Comments: 129904
Be safe and smart TexMex. We are here. Godspeed.
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Quoting ElConando:


2 foot storm surge life threatening?
2' h20 moving with that kind of force will knock anybody's @&& over. Why so many die in flash floods.
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Quoting btwntx08:
im still here but im lurkin for now gonna be a bad afternoon to evening

Stay safe! ur in my prayers
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Quoting Chicklit:
Hi Drak, how long before landfall?


10-12 hours away
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Looks like landfall may be around midnight tonight.
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Member Since: June 9, 2007 Posts: 4 Comments: 15950
Im seeing double!! lol
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Quoting watchingnva:
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...

Yeah, Mexico is not a nice place to be right now... hurricane or no hurricane.
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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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