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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2398. centex
It's been interesting watching sat versus radar on the outer bands in TX and LA. The Sat and Radar do not match like they normally do.
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what an impressive hurricane landfall looks like its going to be around 9pm Est
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What is puzzling is that Alex's pressure kept dropping yet winds increasing very slowly.
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Quoting BobinTampa:
had to duck out, but if Floodman is still around, I'd sure like him to explain how the flood program is 'just fine.'

They are accepting renewal payments but policies are NOT in effect until Congress reauthorizes the program. It will almost certainly be reauthorized retroactively, but if you're one of the ones effected, I doubt 'just fine' is words you'd use to describe the situation.

That's not even mentioning how much money the program loses.


I will tell you. The program will absolutely postively be reauthorized. There is a better chance of Alex spinning up to a 5 and slamming through Tampa right now than there is of the program not being reauthorized.

Flood is an adjuster, my connection to the program is much, much closer.

On the renewals, they are taking them and they will be honored, I can assure you. They are NOT going to deny renewals in the middle of hurricane season and make people re-apply for policies once the program is re-authorized. Why? Because there is a 30 day waiting period for all newly issued policies. The potential litigation that could stem from lapses in this scenario is staggering.

All is fine, the program is solid and will continue on.

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Looks more like GR2 AE

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Landfall imminent

Member Since: August 19, 2006 Posts: 0 Comments: 15826
Quoting Stormchaser2007:
Slowing a bit.

Imagine if it just stalls off the coast and begins to intensify. Let's hope not, but it has been slowing.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Franklin said that Alex may have 3-4 hours over water.

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Recon is going in AGAIN?! How many center passes is this going to be???
Member Since: August 2, 2006 Posts: 46 Comments: 11667
Haven't had time to read the blog much today. The only thing I read was the part around 6 hours ago. Seemed to be filled with mostly wishcasters in one last ditch attempt to "forecast" this cyclone going North. The blog goes through it's own blogogenises with all cyclones. The time I read was the final death rattle from the hope and wish for disaster crowd.
.
.
Once again, the NHC forecast solution proves correct. Thankfully. These cyclones will go where they go, but the last thing we want right now is for a cyclone to effect the oil disaster.
..
To all you wishcasters out there...there's still a breath of hope for your sick wishes. The models were at one point picking up on a possible stall right around the coast. Not looking like that's going to happen...but maybe the thought of it is enough for you to work up an appetite for dinner.....
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2388. GBguy88
Quoting CaicosRetiredSailor:



I guess it depends on how big of a pin one has...


Wasn't Wilma's eye only a mile or two across during her insane deepening?
Member Since: August 22, 2008 Posts: 0 Comments: 483
2387. Asta
wow, Alex really got his act together.
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Just maxed out my photobucket account
lol
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2385. angiest
Quoting xcool:
StormGoddess yeah .i'm pay 79.99%


I am using GRl3, but I will probably add grl2 when I get some more money to waste. ;) Too bad analyst is so expensive.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
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Quoting neonlazer:

This next punch might be a record breaker...
Maybe.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Slowing a bit.

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2381. xcool
StormGoddess yeah .i'm pay 79.99$
Member Since: September 26, 2009 Posts: 2 Comments: 15672
Quoting MiamiHurricanes09:
Nope. They are heading back into the COC.

This next punch might be a record breaker...
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Thanks everyone, didn't expect to get that many replies lol.
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Quoting CybrTeddy:
Could see 105-110 at 9 pm.. followed shortly afterwords by landfall.


So it could be a weak cat. 3. Guess NHC was right.

Quoting leo305:
.

they already said it is possible that Alex could touch CAT 3 intensity before landfall


NHC predicted that this morning. I think the NHC forecasters are morning persons.

Quoting leo305:
if this gets to 946 or lower, it will be the strongest JUNE storm ever.



Technically, in UTC time, it'll be JULY.
Member Since: August 30, 2008 Posts: 8 Comments: 2835
Saffir-Simpson
Hurricane Scale
Category
Pressure
mb
Winds
mph
Depression -- <39
T. Storm -- 39-73
Hurricane 1 > 980 74-95
Hurricane 2 965-980 96-110
Hurricane 3 945-965 111-130
Hurricane 4 920-945 131-155
Hurricane 5 155
Effects and Damage Estimates.
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Quoting Stormchaser2007:
Looks like recons going home.
Nope. They are heading back into the COC.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Wouldn't it be something if Alex continued on a more southerly course that kept him over the water long enough to start feeling the pull from that trough that is supposed to be moving towards him? He might go down the Mexican coast and do a big loop and start coming back up again...probably not but he's been muy loco thus far so who knows?
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Quoting xcool:



ilove GRLevel2 so cool

That is totally cool for real.
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Quoting kmanislander:
This map demonstrates how much what is thought to be the future for a system can deviate from what actually transpires.



Yup, but it did stay within the cone. NHC did a great job on this one ... have a look at model verification on the Alex page of WU. NHC was pretty steady ... especially wrt eventual landfall ... while the other models were flopping around like a fish on a dock.
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Quoting victoriahurricane:


Is that eye small enough to be pinhole?



I guess it depends on how big of a pin one has...
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chaser what happened to the plane now
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Quoting watchingnva:


nope, just as you said that they turned back west to make another loop around...lol

LOL
Alright cool.
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Quoting victoriahurricane:


Is that eye small enough to be pinhole?
No.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
Quoting Stormchaser2007:
Looks like recons going home.
NOOOO!!! (sorrowfully) they won't get the maximum intensity of Alex then!...
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I have 6 live feeds on my site if anyone is wanting! I can't post the link for getting banned but, you can follow it from my WU blog.
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Quoting Stormchaser2007:
Looks like recons going home.


nope, just as you said that they turned back west to make another loop around...lol
Member Since: September 7, 2005 Posts: 7 Comments: 1516
2364. xcool



ilove GRLevel2 so cool


cost 79.99$
Member Since: September 26, 2009 Posts: 2 Comments: 15672
2363. centex
brownsville radar is best today.

Brownsville Long Range Radar
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HurricaneAlex was^heading toward Carboneras,Tamaulipas,Mexico landfall in 5hours
(Straightline projection using its last 2 positions. Take with HUGE grain of salt)

Copy&paste TAM, MOB, PBI, SAL, TAM, MOB, PBI, SAL, 23.4N95.3W, 23.8N95.5W-28.7N88.4W, 24.4N96.2W-28.7N88.4W, 24.5N96.8W-28.7N88.4W, 24.4N96.2W-24.5N96.8W, 24.5N96.8W-24.7N97.8W 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 280.4degrees (~10degrees north of dueWest) while
traveling a distance of 38miles(~61kilometres) over 3hours at a speed of ~13mph(~21kph),
and was 64miles 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 TampaWeatherBuff:


Well, that was my point. You were judging whether it was a Cat 1 based on imagery, hinting it may be much higher. Until we know wind speed at landfall, we cannot judge; imagery is not how these things are measured. I suspect it was Cat 2 perhaps, but not Cat 4.


It is a category 2...lol officially. If the winds were equal with the pressure it'd be at least a category 3.
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Quoting victoriahurricane:


Is that eye small enough to be pinhole?


On satellite images...probably.

Not by the on-board radar on the HH plane.
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2359. NRAamy
Quoting RitaEvac:
OZ drives up to Dairy Queen and figures out its closed



hahahahahahaha!
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Quoting victoriahurricane:


Is that eye small enough to be pinhole?

No, it's about double the size of a pinhole eye.
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Quoting Hurricanes101:
alex moved only .1 degrees in the last hour, he did indeed slow down


I think that's just a retrograde loop (wobble), and it will resume its westward motion. I'm guessing it'll make landfall in about 4.5 hours.

Quoting stormpetrol:
Alex look better as a cat 2 than most cat 4s


Ike had larger surge as a cat. 2 than most cat. 5's. So what about Alex's surge? See comment #2292.
Member Since: August 30, 2008 Posts: 8 Comments: 2835
I always expect band rains up here in Austin to smell different: sea salt and such, but it never does, just smells, looks and acts like non-'tropical' rain.

It would be cool to smell the sea water dropping on you this far inland.
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Looks like recons going home.
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Quoting TampaSpin:
Gotta be at least a Cat2 with this picture.....wow



It is a category 2...100MPH winds
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Quoting CaneAddict:


Uh you don't see a category 4 on satellite looking any better then this or any less.


Well, that was my point. You were judging whether it was a Cat 1 based on imagery, hinting it may be much higher. Until we know wind speed at landfall, we cannot judge; imagery is not how these things are measured. I suspect it was Cat 2 perhaps, but not Cat 4.
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Tornado signature on Nexrad very near the southern tip of South Padre Island heading toward north Brownsville.
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you guys are going too love AUGS
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2350. Patrap
Product: Air Force High Density (HDOB) Message (URNT15 KNHC)
Transmitted: 30th day of the month at 23:08Z
Date: June 30, 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: 51



23:08:00Z 25.517N 96.233W 843.3 mb

(~ 24.90 inHg) 1,470 meters

(~ 4,823 feet) 998.3 mb

(~ 29.48 inHg) - From 114° at 67 knots

(From the ESE at ~ 77.0 mph)

Member Since: July 3, 2005 Posts: 424 Comments: 128314
Quoting Stormchaser2007:
Wow



Is that eye small enough to be pinhole?
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2348. leo305
it stalled on radar
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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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