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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Just did a blog on Alex.
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Alex could of easily mirrored his 2004's occurrence.
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dropsonde is 947mb, there is your lowest pressure
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2944. Patrap
Member Since: July 3, 2005 Posts: 424 Comments: 128283
Hi Everybody,
Looks like Alex has finally pulled it all together.
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2942. angiest
Quoting MiamiHurricanes09:
Not yet.



I can't believe it, his western eyewall looks better than the eastern now.
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2941. Titoxd
Quoting MZV:
I'm starting to wonder if Alex could become the first storm to cross central Mexico and re-form. Usually the Sierra Madres shred tropical formation.


No. It's crossing North Mexico, which is a good 1,000 miles thick. Also, the wind patterns seem to want to send most of the moisture back onto the Great Plains.
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Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed
947mb (27.96 inHg) Sea Level (Surface) 25.4°C (77.7°F) 25.4°C (77.7°F) 100° (from the E) 5 knots (6 mph)
Member Since: October 1, 2007 Posts: 81 Comments: 26511
2939. Patrap
Member Since: July 3, 2005 Posts: 424 Comments: 128283
2938. JamesSA
Quoting MiamiHurricanes09:
Blog pretty quiet for having a category 2 hurricane in the GOM making landfall.
We are just breathing a sigh of relief that it wasn't in Brownsville or Corpus Christi or Galveston or New Orleans... etc.

A sparsely populated area of Northeastern Mexico is a better outcome that some of the other possibilities. That area will be able to take it better than some of the other possible destinations. Lots of ranch land, and the houses tend to be built of concrete.
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2937. HadesGodWyvern (Mod)
getting close to crossing.. maybe 15 more minutes?
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2918

He's not going to cross Mexico, the next front will pick him up and cause flooding through the central U.S. and possibly through the Southeast where it seems to rain everday lately!
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2935. leo305
it's not on land yet.. the center is still over water
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2934. Patrap
Member Since: July 3, 2005 Posts: 424 Comments: 128283
Quoting AstroHurricane001:


Any news links for the Mexico casulties?



A "storm" can span across more than one month. It depends on when exactly the "record" was set.


Another victim:

Link

Video from live feed at Monterrey reporting floods and rivers (in spanish, but images can give a clue):

Link

Keep you posted...
Raining as hell...
Member Since: July 9, 2008 Posts: 8 Comments: 334
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Quoting CybrTeddy:
Hurricane Alex's eye has crossed land at 9:02 pm EDT June 30th, 2010 as a Category 2 hurricane.

Not yet.

Member Since: September 2, 2009 Posts: 130 Comments: 21193
Quoting 1900hurricane:

Next poof of clouds in the Atlantic with decent potential, they'll be back.


Per ECMWF and NOGAPS, that should happen sometime next week.
Member Since: July 8, 2005 Posts: 259 Comments: 24021
Quoting Patrap:
Isabel



Advanced Research WRF High Resolution Simulations of the
Inner Core Structure of Hurricanes Katrina, Rita and Wilma (2005)


3 weeks of no power and 2 trees through the roof...fun fun...no thank you.
Member Since: September 7, 2005 Posts: 7 Comments: 1516
Quoting StSimonsIslandGAGuy:
Storms first named in the NW Caribbean are not Cape Verde storms.

I don't know the official definition, but I would say at a minimum they have to be named east of 50 or 45 W.


92L, which comprised half of Alex's forebearing disturbance, looked like a TS out in the open Atlantic by June 16.

Quoting 1900hurricane:

Dr. Masters reported that there was abundant lightning lining the eye of Hurricane Felix when he was rapidly intensifying.

Link


Another correlation is that high lightning activity in a wave coming off the African coast may be a good predictor for an increased probability of intensification and development when it gets farther west.
Member Since: August 30, 2008 Posts: 8 Comments: 2835
Time: 00:59:30Z
Coordinates: 24.3333N 97.3667W
Acft. Static Air Press: 844.0 mb (~ 24.92 inHg)
Acft. Geopotential Hgt: 1,127 meters (~ 3,698 feet)
Extrap. Sfc. Press: Missing
D-value: -
Flt. Lvl. Wind (30s): From 152° at 95 knots (From the SSE at ~ 109.2 mph)
Air Temp: 18.4°C* (~ 65.1°F*)
Dew Pt: -*
Peak (10s) Flt. Lvl. Wind: 97 knots (~ 111.5 mph)
SFMR Peak (10s) Sfc. Wind: 86 knots (~ 98.9 mph)
SFMR Rain Rate: 13 mm/hr (~ 0.51 in/hr)
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Just got back, do we have official landfall yet?
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Hurricane Alex's eye has crossed land at 9:02 pm EDT June 30th, 2010 as a Category 2 hurricane.

Member Since: July 8, 2005 Posts: 259 Comments: 24021
Quoting Stormchaser2007:


Just because it isnt a US landfall.


isnt that a damn shame too...some of the little kids on here are ridiculous...still think the docs and the other main blogs should be paid...keep the riff raff out a bit better...
Member Since: September 7, 2005 Posts: 7 Comments: 1516
Quoting MiamiHurricanes09:
Blog pretty quiet for having a category 2 hurricane in the GOM making landfall.

Next poof of clouds in the Atlantic with decent potential, they'll be back.
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2921. angiest
Quoting MZV:
I'm starting to wonder if Alex could become the first storm to cross central Mexico and re-form. Usually the Sierra Madres shred tropical formation.


It's happened before I'm pretty sure. Maybe not that far north.
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00:59:30Z 24.333N 97.367W 844.0 mb
(~ 24.92 inHg) 1,127 meters
(~ 3,698 feet) Missing - From 152° at 95 knots
(From the SSE at ~ 109.2 mph) 18.4°C*
(~ 65.1°F*) -* 97 knots
(~ 111.5 mph) 86 knots
(~ 98.9 mph) 13 mm/hr
(~ 0.51 in/hr) 84.2 knots (~ 96.9 mph)
Category Two Hurricane 88.7%
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2918. MZV
I'm starting to wonder if Alex could become the first storm to cross central Mexico and re-form. Usually the Sierra Madres shred tropical formation.
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2917. WxLogic
Good evening...

Well... sure looks that this HURR Season will be rather intense with those HURR that manage to evolve as RI will be norm.
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Quoting MiamiHurricanes09:
Blog pretty quiet for having a category 2 hurricane in the GOM making landfall.


Exactly...the thrill of the chase is over.
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Quoting MiamiHurricanes09:
Blog pretty quiet for having a category 2 hurricane in the GOM making landfall.


Just because it isnt a US landfall.
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AOI
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting Weather456:
A landfall of 100 mph,

right on the money

\

I read your blog every morning and you really nailed this storm.
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2912. kabloie
Recon was fishing for a record beater, hit the eye twice on that run. 948.4 mb is all they get. Almost guys, now please come home, your reports are keeping the rest of us from getting any work done!
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2911. Patrap
Current Conditions
Updated: 17 min 46 sec ago


Brownsville, Texas (Airport)

Heavy Rain
81 °F
Heavy Rain Mist
Humidity: 88%
Dew Point: 77 °F
Wind: 31 mph from the ENE
Wind Gust: 43 mph
Pressure: 29.49 in (Falling)
Heat Index: 88 °F
Visibility: 4.0 miles
UV: 0 out of 16
Pollen: 3.80 out of 12
Pollen Forecast new!
Clouds:
Mostly Cloudy 1900 ft
Mostly Cloudy 3900 ft
Overcast 7500 ft
(Above Ground Level)
Elevation: 20 ft
Member Since: July 3, 2005 Posts: 424 Comments: 128283
2893. mtyweatherfan90

Between A and B, about 90 minutes.
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Blog pretty quiet for having a category 2 hurricane in the GOM making landfall.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
2907. Patrap
Product: Air Force High Density (HDOB) Message (URNT15 KNHC)
Transmitted: 1st day of the month at 00:58Z
Date: July 1, 2010
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Storm Number: 01
Storm Name: Alex (flight in the North Atlantic basin)
Mission Number: 12
Observation Number: 62



00:58:00Z 24.300N 97.450W 844.2 mb

(~ 24.93 inHg) 1,037 meters

(~ 3,402 feet) 949.4 mb

(~ 28.04 inHg) - From 143° at 29 knots

(From the SE at ~ 33.3 mph)

Member Since: July 3, 2005 Posts: 424 Comments: 128283
2906. angiest
Son of a gun ... he wants to build up his western eyewall again.
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2905. Ossqss
Quoting Patrap:


That is the best symmetry he has had.
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A landfall of 100 mph,

right on the money
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Quoting zoomiami:


Can you even imagine that? This one storm took up two weeks of watching. No one would ever get any work done.


And my eyes would be so red from using the computer that people would complain, thinking I'm high.

Quoting KEEPEROFTHEGATE:
LANDFALL



Not yet, the eye didn't make it to the coast by sunset.

Quoting 1900hurricane:
A couple of hours old, but impressive nonetheless:



Looks like a reverse eyewall replacement cycle.
Member Since: August 30, 2008 Posts: 8 Comments: 2835
Time: 00:57:00Z
Coordinates: 24.2667N 97.5W
Acft. Static Air Press: 838.7 mb (~ 24.77 inHg)
Acft. Geopotential Hgt: 1,088 meters (~ 3,570 feet)
Extrap. Sfc. Press: 948.4 mb (~ 28.01 inHg)
D-value:
-
Member Since: October 1, 2007 Posts: 81 Comments: 26511
2900. Patrap
Member Since: July 3, 2005 Posts: 424 Comments: 128283
Alex is the 2nd strongest June hurricane ever recorded with a minimum pressure of 948mb.

That's pretty special if ya ask me.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Remnants, remnants, remnants. Any thoughts on the "land track"?
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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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