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 leo305:
RECON REPORTING

108MPH WINDS


where???
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So we expecting to have the next two new storm form next week... one around the same place Alex from and the other around the Florida Keys..Can someone check the new models... What is your take on this Weather456?Possible two system next week and maybe 3-5 storms in July?
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Quoting reedzone:


Alex looks like a Major Hurricane, not saying it is, but looks like one to me.


Agreed. That's why the Raw T-numbers are so high...I've certainly seen Category 3 or 4 storms look worse than Alex. This will definitely end up as a 100-105 mph storm as it crosses land.
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Did he just give a lurch South?
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1994. leo305
RECON REPORTING

108MPH WINDS
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1993. JamesSA
Quoting Kristina40:
Oz is in Port Isabel. I think the local news guys just interviewed him about his...ahem...strange get up.
The police are trying to locate his space ship.
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1992. russm1
Quoting JamesSA:
Fortunate for Oz it missed him. He's not up to going into a strong storm in any way. If one finds him some day it will cull him from the gene pool.


LOL, he's walking around in a kevlar suit, hockey gear and a motorcycle helment while the other reporters are wearing plastic yellow rain coats..
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1991. IKE
Back in an hour to watch this classic June storm landfall....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting leo305:
This recon pass.. I believe "MAY BE" one of the most shocking we have witnessed in a long time..



Doubt it.
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1989. Grothar
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Hurricane David was the fourth named tropical cyclone, second hurricane, and first major hurricane of the 1979 Atlantic hurricane season. A Category 5 hurricane on the Saffir-Simpson Hurricane Scale, David was among the deadliest hurricanes in the latter half of the 20th century, killing over 2,000 people in its path, mostly in the Dominican Republic.
David was a Cape Verde-type hurricane, traversing through the Lesser Antilles, Greater Antilles, and East Coast of the United States during late August and early September. With winds of 175 mph (280 km/h), Hurricane David was the strongest hurricane to strike the Dominican Republic in recorded history, and the deadliest since the 1930 Dominican Republic Hurricane. Also, the hurricane was the strongest to hit Dominica in the 20th century, and was the deadliest Dominican tropical cyclone since a hurricane killed over 200 in September and of the 1834 season. David was the second male name for a tropical storm since 1952, first to reach Category 5 intensity and the first to be retired.

i guess location is key
Member Since: August 11, 2008 Posts: 3 Comments: 1638
1987. NRAamy
Groth!
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1986. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128736
Another thing to consider, given Alex's untimate formation location in the SW Caribbean, and, this current trajectory basically in the Bay of Campeche is that little to no upwelling has occured in the MDR or Gulf from this particular storm to really cool anything off....The heat content is still there for the other's to follow as we approach maximum heating in August.
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Quoting Stormchaser2007:


Alex looks like a Major Hurricane, not saying it is, but looks like one to me.
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1982. leo305
This recon pass.. I believe "MAY BE" one of the most shocking we have witnessed in a long time..

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1981. 7544
Quoting ChillinInTheKeys:
Nice band approaching Oz.


is there a live feed to see this thats all im reading here
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Oz is in Port Isabel. I think the local news guys just interviewed him about his...ahem...strange get up.
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1979. IKE
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting JamesSA:
Fortunate for Oz it missed him. He's not up to going into a strong storm in any way. If one finds him some day it will cull him from the gene pool.


Oh my goodness...I just spit drink all over the screen.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
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stalling again and drifting south posssibly
Member Since: July 14, 2008 Posts: 1 Comments: 9630
Nice band approaching Oz.
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so alex is deciding to come in about 90-100 miles south of the border in the next 2 hours...
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Looks like recon's setting up for one more pass.
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1972. JamesSA
Quoting doabarrelroll:

look at Oz's video and you tell me
Fortunate for Oz it missed him. He's not up to going into a strong storm in any way. If one finds him some day it will cull him from the gene pool.
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1971. leo305
Quoting Hurricanes101:


think you quoted the wrong person lol


yea lol, I quoted the guy saying "not likely, it only has 2-4 hours over water"

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Quoting HurricaneSwirl:


Oz is nowhere near the center.. unfortunately.


exactly my point, this storm is in no way "weak"
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1969. Grothar
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Quoting doabarrelroll:

look at Oz's video and you tell me


Oz is nowhere near the center.. unfortunately.
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Quoting leo305:


that didn't stop charley from jumping from CAT 2 to CAT 4 in that same amount of time


think you quoted the wrong person lol
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Quoting TankHead93:
Is it in the realm of possibility that Alex could rapidly intensify right up until it makes landfall to become a major?


It's not likely because even if there are rapid pressure drops all the way until landfall I don't believe the winds will fully catch up. But it's certainly not impossible. I would say 105 mph will be the peak intensity.
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What are the hurricane hunters up to?
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1964. leo305
Quoting Hurricanes101:


Pay attention, where he is they are getting the outer parts of the system

That in no way reflects what the core of the storm is as a whole.


that didn't stop charley from jumping from CAT 2 to CAT 4 in that same amount of time
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1963. GBguy88
Quoting HurricaneSwirl:


Unlikely, before it goes over land it only has one advisory left at 7 PM, will probably be inland by 9. But a CAT2 is likely imo.


My guess is 100mph at landfall.
Member Since: August 22, 2008 Posts: 0 Comments: 483
Quoting TankHead93:
Is it in the realm of possibility that Alex could rapidly intensify right up until it makes landfall to become a major experts?


Probably not.

It only has 2-4 hours left.
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Quoting doabarrelroll:

look at Oz's video and you tell me


Pay attention, where he is they are getting the outer parts of the system

That in no way reflects what the core of the storm is as a whole.
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1959. Titoxd
000
WTNT51 KNHC 302150
TCEAT1
HURRICANE ALEX TROPICAL CYCLONE POSITION ESTIMATE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010
500 PM CDT WED JUN 30 2010

AT 5 PM CDT THE CENTER OF HURRICANE ALEX WAS ESTIMATED NEAR LATITUDE
24.4 NORTH...LONGITUDE 97.1 WEST OR ABOUT 60 MILES...95 KM...
NORTHEAST OF LA PESCA MEXICO AND ABOUT 105 MILES...170 KM...
SOUTH-SOUTHEAST OF BROWNSVILLE TEXAS.

$$
FORECASTER PASCH/BERG
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Is it in the realm of possibility that Alex could rapidly intensify right up until it makes landfall to become a major experts?
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Quoting stormpetrol:
HH just measured a pressure of 955mb and with the satelite presentation at this time , i think its a possibility Alex could become a cat 3 before or just at landfall making it the first the major hurricane of the 2010 season.


Unlikely, before it goes over land it only has one advisory left at 7 PM, will probably be inland by 9. But a CAT2 is likely imo.
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1956. leo305
Quoting TankHead93:
Is it in the realm of possibility that Alex could rapidly intensify right up until it makes landfall to become a major?


yes its possible
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Quoting Weather456:
Didnt take the season long to show its colours.


yep... first named storm and BOOM
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1954. IKE
Member Since: June 9, 2005 Posts: 23 Comments: 37858
HH just measured a pressure of 955mb and with the satelite presentation at this time , i think its a possibility Alex could become a cat 3 before or just at landfall making it the first the major hurricane of the 2010 season.
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Final approach.


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Is it in the realm of possibility that Alex could rapidly intensify right up until it makes landfall to become a major?
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if they were going off of raw ADT number we would have a 115 knt cat 4 hurricane
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He's beautiful.
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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.