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 StSimonsIslandGAGuy:
The eye in homegirl's post 1562 looks the best I've seen from Alex.

Here's the visible couterpart to it:

Member Since: Posts: Comments:
1596. KORBIN
Since we know what's going on with Alex,

What is our 4th of July going to look like for the rest of the Gulf Coast?

Any Spurious Lows? Blobs? Invests? Aoi?
Member Since: Posts: Comments:
Quoting Tazmanian:




old
??? It's from 30 minutes ago. That's not old.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting Baltimorebirds:
Alex looks intense.Thank god it's running out of time over water.I told people this was going to be one of thoses storms that start to intensify close to land,just like dolly Ike and charley.

agreed!
Member Since: August 16, 2009 Posts: 1 Comments: 93
Quoting Stormchaser2007:
Wow



For as long as he took to get to Hurricane status. He turned out to be a nice looking storm...
Member Since: Posts: Comments:
Quoting atmosweather:
000
URNT12 KNHC 302013
VORTEX DATA MESSAGE AL012010
A. 30/19:54:00Z
B. 24 deg 24 min N
096 deg 42 min W
C. 850 mb 1090 m
D. 60 kt
E. 223 deg 10 nm
F. 330 deg 69 kt
G. 236 deg 51 nm
H. 959 mb
I. 15 C / 1523 m
J. 22 C / 1525 m

K. 20 C / NA
L. CLOSED
M. C12

N. 12345 / 8
O. 0.02 / 2 nm
P. AF304 1201A ALEX OB 14
MAX FL WIND 90 KT NE QUAD 19:59:00Z
MAX OUTBOUND FL WIND 90 KT NE QUAD 19:59:00Z




old
Member Since: May 21, 2006 Posts: 5091 Comments: 115437
Member Since: Posts: Comments:
1589. Drakoen
4mph more from the latest SFMR to be a Category 2 storm. I'm out for a bit.
Member Since: October 28, 2006 Posts: 57 Comments: 30727
IR imagery shows tremendous convection developing and wrapping around the eye of Alex, too much too late.
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Quoting Orcasystems:


You been drinking that stuff from the copper tubes again... haven't.



lol
Member Since: May 21, 2006 Posts: 5091 Comments: 115437
000
URNT12 KNHC 302013
VORTEX DATA MESSAGE AL012010
A. 30/19:54:00Z
B. 24 deg 24 min N
096 deg 42 min W
C. 850 mb 1090 m
D. 60 kt
E. 223 deg 10 nm
F. 330 deg 69 kt
G. 236 deg 51 nm
H. 959 mb
I. 15 C / 1523 m
J. 22 C / 1525 m

K. 20 C / NA
L. CLOSED
M. C12

N. 12345 / 8
O. 0.02 / 2 nm
P. AF304 1201A ALEX OB 14
MAX FL WIND 90 KT NE QUAD 19:59:00Z
MAX OUTBOUND FL WIND 90 KT NE QUAD 19:59:00Z
Member Since: Posts: Comments:
looks like Alex is makeing land fall or this about be come hes runing out of water
Member Since: May 21, 2006 Posts: 5091 Comments: 115437
1584. Gorty
Alex is really starting to ramp up, wow!

Alex might be going either W or WSW.
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1583. angiest
6 inches of rain in the last hour...

Photobucket
Member Since: August 26, 2006 Posts: 16 Comments: 4766
CAT 4? not yet. not sure if it has that much time to rapidly intensify. its only got a few more hours over the GOM.
Member Since: August 16, 2009 Posts: 1 Comments: 93
Quoting Tazmanian:
wohoooooooo Alex made it too cat 4


You been drinking that stuff from the copper tubes again... haven't you
Member Since: October 1, 2007 Posts: 81 Comments: 26512
Should be getting out next update soon...
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Wow

Member Since: Posts: Comments:
1577. SeALWx
Quoting StormSurgeon:


weee oooo weeee ooooo, run Flood, the blog police are coming for you.....LOL.....and me too for this wortless post....

No posts are truly worthless, it's just that some are worth less than others! :)
Member Since: April 2, 2010 Posts: 0 Comments: 196
Quoting Drakoen:


Yes...i've been on here too long lol




oh rates
Member Since: May 21, 2006 Posts: 5091 Comments: 115437
Great job EURO & NHC!!!

Viva La Mexico
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Quoting CybrTeddy:
IMO, I think 5 pm will have 90 mph winds with a pressure of 959 mb.
It should have 95mph winds from what Recon is reporting. Lots of 93mph SFMR readings.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
What are the thoughts of the winds at the next "official" update?
Member Since: August 16, 2009 Posts: 1 Comments: 93
1570. Drakoen
Quoting Thundercloud01221991:


do you mean 2


Yes...i've been on here too long lol
Member Since: October 28, 2006 Posts: 57 Comments: 30727
1569. tkeith
1561. Orcasystems 3:22 PM CDT on June 30, 2010

might hit that Cat 2 status yet...
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Pretty strong squalls starting to pound my area...Rain up to 2" and 15mph sustain winds with gusts to 20mph Alex is getting felt here in South Louisiana and Mississippi...This is a big storm affecting the whole gulf...
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IMO, I think 5 pm will have 90 mph winds with a pressure of 959 mb.
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Quoting Baltimorebirds:
are you talking about pressure? or winds.It can't be a major.
pressure doesn't run in MPH's
Member Since: February 27, 2010 Posts: 0 Comments: 1125
Quoting TI882:
Did I miss something about the 123mph winds on the barrier island? and the 93mph NW of center?

Time: 19:14:30Z
Coordinates: 25.0667N 97.5W
Acft. Static Air Press: 843.2 mb (~ 24.90 inHg)
Acft. Geopotential Hgt: 1,442 meters (~ 4,731 feet)
Extrap. Sfc. Press: 996.7 mb (~ 29.43 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 46° at 70 knots (From the NE at ~ 80.5 mph)
Air Temp: 15.1°C (~ 59.2°F)
Dew Pt: 14.8°C (~ 58.6°F)
Peak (10s) Flt. Lvl. Wind: 71 knots (~ 81.6 mph)
SFMR Peak (10s) Sfc. Wind: 107 knots* (~ 123.0 mph*)
SFMR Rain Rate: 11 mm/hr* (~ 0.43 in/hr*)

Time: 19:58:00Z
Coordinates: 24.55N 96.55W
Acft. Static Air Press: 844.2 mb (~ 24.93 inHg)
Acft. Geopotential Hgt: 1,229 meters (~ 4,032 feet)
Extrap. Sfc. Press: Missing
D-value: -
Flt. Lvl. Wind (30s): From 131° at 82 knots (From the SE at ~ 94.3 mph)
Air Temp: 17.5°C* (~ 63.5°F*)
Dew Pt: -*
Peak (10s) Flt. Lvl. Wind: 84 knots (~ 96.6 mph)
SFMR Peak (10s) Sfc. Wind: 81 knots* (~ 93.1 mph*)
SFMR Rain Rate: 24 mm/hr* (~ 0.94 in/hr*)



You missed the asterisks beside those numbers, which indicate suspect data.
Member Since: July 15, 2005 Posts: 3 Comments: 1270
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Time: 19:58:00Z
Coordinates: 24.55N 96.55W
Acft. Static Air Press: 844.2 mb (~ 24.93 inHg)
Acft. Geopotential Hgt: 1,229 meters (~ 4,032 feet)
Extrap. Sfc. Press: Missing
D-value: -
Flt. Lvl. Wind (30s): From 131° at 82 knots (From the SE at ~ 94.3 mph)
Air Temp: 17.5°C* (~ 63.5°F*)
Dew Pt: -*
Peak (10s) Flt. Lvl. Wind: 84 knots (~ 96.6 mph)
SFMR Peak (10s) Sfc. Wind: 81 knots* (~ 93.1 mph*)
SFMR Rain Rate: 24 mm/hr* (~ 0.94 in/hr*)
Member Since: October 1, 2007 Posts: 81 Comments: 26512
Quoting StormSurgeon:


weee oooo weeee ooooo, run Flood, the blog police are coming for you.....LOL.....and me too for this wortless post....


A wortless post??? Ewwww.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
1558. tkeith
anyway it is what it is

yep...
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Quoting StSimonsIslandGAGuy:
I remember the talk about integrated kinetic energy index when Ike was in the Gulf---what is the integrated kinetic energy index for Alex?


I seem to recall a recent estimate in the 2.5 to 3 range, but I'm open to correction on that.
Member Since: July 15, 2005 Posts: 3 Comments: 1270
HurricaneAlex was^heading toward Matamoros,Mexico landfall in 5hours
(Straightline projection using its last 2 positions. Take with HUGE grain of salt)

Copy&paste TAM, MOB, PBI, SAL, 23.3N95.1W, 23.4N95.3W-28.7N88.4W, 23.8N95.5W-28.7N88.4W, 24.4N96.2W-28.7N88.4W, 23.8N95.5W-24.4N96.2W, 24.4N96.2W-25.5N97.5W into the GreatCircleMapper.

The shortest red line denotes the heading between the last two positions. Below the map shows:
H.Alex had a heading of 313.2degrees (~2degrees west of NorthWest) while traveling
a distance of 61miles(~98kilometres) over 3hours at a speed of ~20mph(~33kph);
and was 111miles away from the coast in the direction of its heading.


^ EXTRAP or straightline projections are not forecasts of what will happen in the future,
especially not for TropicalCyclones. They merely aftcast what has already happened.
* DeepwaterHorizon is marked at 28.7N88.4W
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Quoting Patrap:


amazing radar shot, looks like a mini vortex inside the larger hurricane, pretty cool to see
Member Since: March 10, 2010 Posts: 1 Comments: 7874
Quoting Drakoen:
Alex needs another 4 mph to be considered a category 4 according to the latest SFMR
Category 4, really?
Member Since: September 2, 2009 Posts: 130 Comments: 21194
1553. Buhdog
i can't believe the haters with OZ...if you don't like it, don't watch. Nobody will associate you with him if you watch (if that were even possible)

It's like nascar, I'm watching for the wrecks and it's free...now I just need a beer.

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Quoting Drakoen:
Alex needs another 4 mph to be considered a category 4 according to the latest SFMR


do you mean 2
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Quoting Floodman:
You know, people come and go here; there are a great number of people that post here that have been here since I joined 6 years ago, but it never ceases to amaze me that there are those who feel that they know best what needs to be done and they appoint themselves "The Blog Police"...they are invariably the newest members and they are, in general, humorless dry and unpleasant


weee oooo weeee ooooo, run Flood, the blog police are coming for you.....LOL.....and me too for this wortless post....
Member Since: September 1, 2007 Posts: 0 Comments: 1793
1550. angiest
Quoting Drakoen:
Alex needs another 4 mph to be considered a category 4 according to the latest SFMR


What???
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting Drakoen:
Alex needs another 4 mph to be considered a category 4 according to the latest SFMR




i new it would make it too cat 4 YAY ME
Member Since: May 21, 2006 Posts: 5091 Comments: 115437
Quoting twhcracker:


i am surprised he isnt using a mullet as a cigarette holder while doing the backstroke in the storm surge


Just wait, he'll do that later.
Member Since: April 26, 2009 Posts: 3 Comments: 3667

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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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