Large and intensifying Hurricane Alex bears down on northeastern Mexico, South Texas

By: Dr. Jeff Masters , 2:23 PM GMT on June 30, 2010

Share this Blog
3
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 2748 - 2698

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61Blog Index

Quoting Abacosurf:
Always worse to have an intensifying system at landfall.

God bless anyone in his path.



Agree 100%; imagine if this had been an East Coast storm crossing the Gulf Stream just before landfall.....Prayers for the folks in Mexico that will have to deal with this in the coming days.
Member Since: Posts: Comments:
2747. mobal
Just got off the phone with SoLoco in McAllen. Looks like flooding is already an issue there and in Reynosa MX.

Power is still on but he has a prep kit just in case to keep the little ones and MRS. happy.

Got his camera in hand!

He is flying home (BAMA) for the weekend Friday, was worried.....I told him to go for it, he should be fine....

Member Since: Posts: Comments:
2746. IKE
Quoting 1900hurricane:

I'd agree that there is a much higher than normal probability of Alex's retirement if he does the stuff that we expect him to do. But then again, Emily wasn't retired. One thing's for sure though, this season definitely started off with a bang!


I hate to see this season if there is 23 named systems.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting mtyweatherfan90:
Dang it, Alex has claimed now a death toll. 3 people died in a carcrash southeast of Monterrey in Nuevo León due to extreme rainfall and poor visibility. Also several mudslides have been reported at Monterrey-Saltillo Highway which passes right next to the Sierra Madre Range




My homemade rain gauge reports around 75 mm in the last 4 hours (3/4 in. per hour). Several underpasses and roads are closed due to floods. Creeks about to crest. Main river, Santa Catarina River, is around 40% its capacity. And the worse is yet to come. Pictures soon...


Unfortunately, there will be more as Alex rains itself out and the orographic lift becomes enhanced over he mountainous terrain of north-central Mexico - mudslides will be numerous over the next few days.
Member Since: August 27, 2006 Posts: 0 Comments: 1785
2743. leo305
Quoting seflagamma:

But Andrew was in late August...

I was here for Andrew...
it was the first sorm of the seaon in a slow year..

but it was not in June..


yea I know, but how rare can it be to have the first named system of a Hurricane Season to be a CAT 5?
Member Since: Posts: Comments:
Recon wont be able to do a center pass unless they have received clearance from the Mexican government.

Plus they're probably low on fuel.
Member Since: Posts: Comments:
Quoting Stormchaser2007:


June 12th (Pre-Alex)



Isn't it amazing where these storms come from, that wave was fairly impressive, but it went largely unnoticed across the Atlantic, due to 92L.

To me it is so amazing what these system can turn into in such a short amount of time
Member Since: March 10, 2010 Posts: 1 Comments: 7874
Quoting IKE:
Flooding in Mexico could be terrible. Hate to see what the death toll may be. Hopefully I'm wrong.

I think Alex may get retired after everything is over.

I'd agree that there is a much higher than normal probability of Alex's retirement if he does the stuff that we expect him to do. But then again, Emily wasn't retired. One thing's for sure though, this season definitely started off with a bang!
Member Since: August 2, 2006 Posts: 47 Comments: 11709
2739. Patrap
Quoting StSimonsIslandGAGuy:
It's still June in Mexico

So a question for the knowledgeable bloggers:

When compiling monthly statistics of storms, does the NHC use eastern time (Miami time) or universal time?

Is Alex now in June or July?




UTC..its only Numbers.

Member Since: Posts: Comments:
2738. leo305
Quoting IKE:
Widespread power outages in Brownsville,TX.


the sad part, that's with just Tropical storm force wind gusts..

Miami lost power for 3 weeks with just CAT 1 hurricane winds from wilma..
Member Since: Posts: Comments:
i think i sould work for the nhc i will be your best DOOM day forcaster
Member Since: Posts: Comments:
Quoting leo305:


Andrew was one of those rare first storms, so was Audrey

But Andrew was in late August...

I was here for Andrew...
it was the first sorm of the seaon in a slow year..

but it was not in June..
Member Since: Posts: Comments:
Always worse to have an intensifying system at landfall.

God bless anyone in his path.

Member Since: Posts: Comments:
We have seen a 34mb drop in 24 hours.

Amazing.
Member Since: Posts: Comments:
2732. Patrap
Member Since: Posts: Comments:
2731. IKE
Widespread power outages in Brownsville,TX.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
2730. SLU


Alex is putting on a real show ... and it's only the season opener!

Looks liks a cat 3 to me ....
Member Since: Posts: Comments:
oh well there all ways post season
Member Since: Posts: Comments:
Good thing Alex headed west otherwise it may have been a cat 3
Member Since: Posts: Comments:
Quoting neonlazer:
HH coming in for the grande finale?
Possibly.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting MiamiHurricanes09:
Believe it or not Alex came from a tropical wave from Africa, the image was posted a couple pages back as it emerged. So it is a possibility that it can develop once it gets into favorable conditions.


June 12th (Pre-Alex)

Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Believe it or not Alex came from a tropical wave from Africa, the image was posted a couple pages back as it emerged. So it is a possibility that it can develop once it gets into favorable conditions.


Ah. Are there favorable conditions ahead of it right now? Because after Alex makes landfall we'll be bored. :)
Member Since: Posts: Comments:
2724. IKE
Flooding in Mexico could be terrible. Hate to see what the death toll may be. Hopefully I'm wrong.

I think Alex may get retired after everything is over.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
2723. JLPR2
Quoting sarahjola:
what?


That is supposed to show were the center is and were is the yellow point?
I guess theyll say... whoops XD
Member Since: Posts: Comments:
HH coming in for the grande finale?
Member Since: Posts: Comments:
2721. leo305
Quoting seflagamma:


SSI .. is it Mike or Rich? I agree with you on this....

this is not a normal "first storm of the season"


Andrew was one of those rare first storms, so was Audrey
Member Since: Posts: Comments:
Quoting Snowlover123:


Miami... do you think it'll develop?
Believe it or not Alex came from a tropical wave from Africa, the image was posted a couple pages back as it emerged. So it is a possibility that it can develop once it gets into favorable conditions.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Alex did not dissapoint; he finally turned into the large monster he was destined to be near landfall.....
Member Since: Posts: Comments:
If you go with UTC sure.

NHC will measure it as a June landfall however.
Member Since: July 8, 2005 Posts: 259 Comments: 24576
No wind change for the 9pm unless they update this.

AL, 01, 2010070100, , BEST, 0, 244N, 973W, 85, 948, HU, 64, NEQ,
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
948 mb is incredible for a June hurricane!


SSI .. is it Mike or Rich? I agree with you on this....

this is not a normal "first storm of the season"
Member Since: Posts: Comments:
2714. scott39
Quoting WatchingThisOne:


Not GMT/UTC/Zulu it ain't ... we're 30 minutes into July.
Will somebody please explain this
Member Since: Posts: Comments:
2713. angiest
Quoting snotly:



Yes, and it finally lost most of its wobble so now the inflow in congruent too. Not much water left. I'd say gusts to 140 mph down there on the surface.


I still see more greens in the last few scans than earlier when there was more yellow and orange.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting MiamiHurricanes09:
Impressive tropical wave...



Miami... do you think it'll develop?
Member Since: Posts: Comments:
Dang it, Alex has claimed now a death toll. 3 people died in a carcrash southeast of Monterrey in Nuevo León due to extreme rainfall and poor visibility. Also several mudslides have been reported at Monterrey-Saltillo Highway which passes right next to the Sierra Madre Range




My homemade rain gauge reports around 75 mm in the last 4 hours (3/4 in. per hour). Several underpasses and roads are closed due to floods. Creeks about to crest. Main river, Santa Catarina River, is around 40% its capacity. And the worse is yet to come. Pictures soon...
Member Since: Posts: Comments:
oz is back
Member Since: September 22, 2005 Posts: 11 Comments: 2032
2709. centex
It's not going to intensify when outer eyewall over land.
Member Since: Posts: Comments:
According to news - landfall is when the center passes over land -- not the beginning of the eyewall
Member Since: Posts: Comments:
Quoting Drakoen:
The system makes landfall when the absolute center of the system comes on shore.


Thanks for clarifying that Drak.
Member Since: Posts: Comments:
Quoting CybrTeddy:


Oh, great, looks like a lull in seasonal average hurricane activity around July 9!

Quoting MiamiHurricanes09:
I'm thinking 9PM EDT.


I'm thinking 11 pm EDT, 10 pm CDT. However if you go with NHC's definition of a landfall as the point when every last bit of the eyewall comes ashore then that will have to be 0:30 AM EDT July 1.
Member Since: August 30, 2008 Posts: 8 Comments: 2835
Perhaps we cannot use the term in "pin hole" eye...but "stadium" is becoming more accurate than before..

see if this link works...
"http://www.esl.lsu.edu/animate/goes/index.php?region=gulf&channel=ir"
Member Since: June 26, 2008 Posts: 0 Comments: 383
Quoting seflagamma:
this storm is making landfall now...
and it looks strong.
No landfall yet. Could take another hour or two.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting JLPR2:
Something is wrong here:

XD
what?
Member Since: Posts: Comments:
A July landfall
Member Since: Posts: Comments:
2701. Drakoen
The system makes landfall when the absolute center of the system comes on shore.
Member Since: Posts: Comments:
2700. snotly
Quoting StormChaser81:


Eyewall is looking better, notice the expanding yellow colors and some reds in the radar. Thats a sign of a deepening eyewall.




Yes, and it finally lost most of its wobble so now the inflow in congruent too. Not much water left. I'd say gusts to 140 mph down there on the surface.
Member Since: Posts: Comments:
Quoting weatherwatcher12:

It is June. It's June 30th.


Not GMT/UTC/Zulu it ain't ... we're 30 minutes into July.
Member Since: Posts: Comments:
2698. centex
Sat people are running behind those watching radar.
Member Since: Posts: Comments:

Viewing: 2748 - 2698

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
35 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron