Intensifying Hermine closes in on the Texas/Mexico coast

By: Dr. Jeff Masters , 9:47 PM GMT on September 06, 2010

Share this Blog
1
+

Steadily intensifying Tropical Storm Hermine is closing in on the coast near the Texas/Mexico border, and should move ashore late tonight. Hermine became a tropical depression at 11pm last night, and could become a minimal hurricane by 11 pm tonight. Hermine's rate of intensification from nothing to a strong tropical storm is one of the fastest on record. It turns out that the extreme southwestern Gulf of Mexico's Bay of Campeche, where Hermine formed, is prone to these sort of rapidly intensifying tropical storms. The curvature and topography of the land help induce a counter-clockwise spin to the air over the region, which helps get tropical storms spinning up unusually quickly. Helping the spin-up process are the very warm 30°C waters, low 5 - 10 knots of wind shear, and moist atmosphere. Hermine promises to be a very wet storm, and latest long range radar out of Brownsville, Texas shows a large area of heavy rain has been drenching southern Texas and northern Mexico all afternoon, with radar estimated rainfall amounts exceeding two inches in a few areas along the coast. Radar loops show that an eyewall is attempting to form, but a region of dry air from over land spiraled into Hermine's core between 4 - 5pm EDT, disrupting eyewall formation. However, it now appears that Hermine has closed off its eye from this dry air, which should aid in intensification. Satellite imagery shows Hermine has vigorous thunderstorms with very cold tops, and improving low-level spiral banding.

Forecast for Hermine
Hermine doesn't have much time over water before it comes ashore, which is a good thing. The storm is steadily organizing, and has a shot at reaching hurricane strength before the center moves ashore late tonight, near midnight. Heavy rain will be the main threat from Hermine, though isolated tornadoes may also cause damage, particularly over South Texas. Hermine is expected to accelerate through Central Texas Tuesday and Wednesday, and the storm's rains will help alleviate moderate to severe drought conditions affecting Central Texas.


Figure 1. Late afternoon radar image of Tropical Storm Hermine. Note the band of dry air spiraling into the core of the storm from the north.

Gaston continues to suffer from dry air
An Air Force Hurricane Hunter aircraft spent the afternoon in Gaston's remains, and found a weak 1012 mb center of low pressure with only a limited region of westerly winds on the south side of the center of circulation. Top surface winds uncontaminated by heavy rain seen by their SFMR instrument were in the 30 - 35 mph range. The airplane found plenty of dry air in the storm's environment, and there are not enough heavy thunderstorms in ex-Gaston's circulation for it to qualify as a tropical depression. The remains of Gaston are now approaching the northern Lesser Antilles, and residents can expect a few heavy rain showers and wind gusts up to 40 mph beginning early this evening and continuing into the night. Latest radar out of Martinique doesn't show much in the way of heavy rain, and satellite imagery confirms that the thunderstorm activity associated with Gaston's remains is quite sparse. A large amount of dry air surrounds Gaston's remains on all sides, as seen on water vapor satellite loops.


Figure 2. Afternoon satellite image of the remains of Gaston, approaching the Lesser Antilles Islands.

Forecast for Gaston
There is little change to the forecast for Gaston's remains. Dry air will continue to be the major impediment to development, and the system is unlikely to become a tropical depression today. However, wind shear, which is currently a moderate 10 knots, is forecast by the latest SHIPS model run to fall very low, 0 - 5 knots, tonight through Wednesday. With almost no wind shear affecting it, Gaston will a better chance of keeping the moisture from its heavy thunderstorms near its core on Tuesday. This will insulate the storm from the dry air surrounding it. The atmosphere is also moister in the eastern Caribbean, further increasing the chances of development. I believe it is probable Gaston will become a tropical depression again on Tuesday. NHC is currently giving Gaston a 70% chance of developing into a tropical depression by Wednesday, which is a reasonable forecast.

Heavy rain showers and gusty winds from the storm will affect Puerto Rico Tuesday morning through Wednesday afternoon. This activity will spread to the Dominican Republic Tuesday afternoon through Thursday morning. Assuming dry air and an encounter with Hispaniola's high mountains do not destroy Gaston, heavy rain from the storm should move over Haiti, eastern Cuba, and Jamaica Wednesday night and Thursday morning. The models don't give much support for Gaston surviving past Wednesday. The ECMWF, GFS, NOGAPS, Canadian, and HWRF models all dissipate Gaston. However, two models--the GFDL and UKMET--predict that Gaston will survive the dry air and an encounter with Hispaniola, and pass far enough south of the island to find a favorable environment in the Central Caribbean for development on Wednesday. Wind shear will be low, water temperatures will be hot, and the atmosphere will be plenty moist. Gaston could intensify into a hurricane in the Western Caribbean by the end of the week, as predicted by the latest run of the GFDL model.

Elsewhere in the tropics
The models are fairly unanimous in predicting development late this week of a tropical wave expected to emerge from the coast of Africa on Tuesday or Wednesday. The next storm will be called Igor.

Next post
I'll have an update in the morning.

Jeff Masters

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: 936 - 886

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 | 34Blog Index

Quoting want2lrn:


great....now i am confused all over again. lol i guess it is back to the books for me!

Storms are steered by several things....
The location of high and low pressure areas being important too.
And right now, even if Gaston was a powerfull hurricane, he would tend to go west.

Member Since: October 24, 2005 Posts: 0 Comments: 24676
Quoting 954FtLCane:
DISH BACK~!!!!! wow Hermine is hot, I would date her
\
Break from the blog in order.
Just turn off the computer and walk away.
Member Since: Posts: Comments:
26-21 BSU missed EP 5:31 3rd
Good evening.

I see we have no circle on the new African wave. That's a little surprising and non surprising at the same time.
I think we'll see a yellow circle tomorrow if it stays with convection.

Best of luck to those being affected by Hermine tonight, stay safe!
Member Since: Posts: Comments:
Quoting traumaboyy:


rats!!!

Go Canes!!! Go ACC!!! and I hope the little Bronkettes lose tonite
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting GTcooliebai:

yEP and that will be there only lead of the night. cause Boise State Just scored!


rats!!!
Member Since: Posts: Comments:
Just an observation, but Hermine's eye is still over mostly water inside the barrier islands...
Member Since: August 28, 2005 Posts: 0 Comments: 113
boise back in lead 26-21
Member Since: Posts: Comments:
Quoting F4PHANTOM:
and they can ride off together into the sunrise of the north atlantic lol


Doesn't look like that's going to happen according to the G F S! model sir.
Member Since: Posts: Comments:
Quoting 954FtLCane:
Va Tech just took the lead 21-20


Yess....good for ACC....GO NOLES!!
Member Since: Posts: Comments:
Quoting 954FtLCane:
Va Tech just took the lead 21-20

yEP and that will be there only lead of the night. cause Boise State Just scored!
Member Since: Posts: Comments:
99L should be making a comeback.. afterall models did pick up on that and not gaston
Member Since: April 17, 2010 Posts: 0 Comments: 1753
921. 7544
99l looking better than gasser now
Member Since: Posts: Comments:
Quoting F4PHANTOM:
supposed to be ending for the past 5 weeks.

LOL
Member Since: October 24, 2005 Posts: 0 Comments: 24676
Member Since: Posts: Comments:
Quoting want2lrn:


I will trade you current game status for future climatology questions... 21-20 VT, 6:34 3rd


Deal.....but I may refer any non medical questions to the truly intelligent people in the blog......IF I EVER MEET THEM......LMFAO!!
Member Since: Posts: Comments:
Quoting futureguy:
Man latest sat view shows 100,000 Mexicans with inner tubes getting ready for the free water rapids ride accross the border. LOL

Tacky hater arent you?
Member Since: Posts: Comments:
Quoting ticka1:


Depends on which way Hermine moves since she's moved onshore...will it move north and more towards central texas or will it move more west. Definitely no more rain on the radar for now and none moving ashore from the GOM like earlier.


It was probably more of a daytime heating thing for us. We have a 100% chance of rain here tomorrow so I am sure it will be back. There are some small storms streaming this way, very tiny tho.
Member Since: July 5, 2010 Posts: 0 Comments: 170
The current moisture off of Africa will not develop, but it will lay a MONSTROUS foundation of blobby moisture that will lead to the eventual formation of IGOR in about 48 to 72 hours and IGOR will be THE ONE.

And Janet will be his girlfriend.
Member Since: Posts: Comments:
Va Tech just took the lead 21-20
Member Since: Posts: Comments:
Updated



AOI

AOI

AOI

AOI

AOI

AOI


TS BUSTED FORECAST ALIBI
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting traumaboyy:


Thank You very much.....Can not watch it at work!!


I will trade you current game status for future climatology questions... 21-20 VT, 6:34 3rd
Quoting EtexJC:

http://espn.go.com/espn3/player?gameId=302490259&league=ncaaf


Thanks....but very limited access here on state computer and anything to do with sports is blocked!!
Member Since: Posts: Comments:
Models have anything coming to the US in the near future? Lol peak of the season nears and all we have is a TS to blog about. What gives? VT UP 21 to 20
Member Since: Posts: Comments:
Quoting traumaboyy:


NO MORE DONUTS!!! THIS BLOG GOES CRAZY DURING THE NIGHT SHIFT ON SUGAR!!!


Ain't that the truth! LOL
Member Since: Posts: Comments:
Quoting houstongator:
Looks like the rain just faded away here in SE Texas (Houston) once it got west of 610. Everything in the Gulf has just faded also - probably be back tomorrow though.


Depends on which way Hermine moves since she's moved onshore...will it move north and more towards central texas or will it move more west. Definitely no more rain on the radar for now and none moving ashore from the GOM like earlier.
Member Since: Posts: Comments:
Quoting Leafgreen:

I believe this is due to the JMO cycle of the last few weeks. I remember from Dr. Masters' post that it is forcast to end about now, although these forecasts are not always reliable.

TRue.
Loads of moisture in the ITCZ. And that wave now coming off is tapping that.
Needs to stay south to keep developing.
, moisture-wise.
Member Since: October 24, 2005 Posts: 0 Comments: 24676
DISH BACK~!!!!! wow Hermine is hot, I would date her
Member Since: Posts: Comments:
Quoting traumaboyy:


Thank You very much.....Can not watch it at work!!

http://espn.go.com/espn3/player?gameId=302490259&league=ncaaf
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting want2lrn:
For those of you wanting to know, but unable to watch. Boise just turned it over on their own 27. 9:16 left in the third qtr, 20-14 BSU


Thank You very much.....Can not watch it at work!!
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting pottery:

The dry air in the Atl. is the one thing that has prevented the explosion we expected for 2010. So far.
I wonder if it will change soon?

I believe this is due in part to the JMO cycle of the last few weeks. I remember from Dr. Masters' post that it is forecast to end about now, although these forecasts are not always reliable.
Member Since: Posts: Comments:
Quoting stormpetrol:
My 25th Wedding Anniversary is tomorrow(Silver)and I love my wife more today than I did yesterday but not as much as tomorrow. Catch up with you all Wednesday, hopefully :)


Happy Anniversary, here's wishing many more happy years together !
Member Since: Posts: Comments:
Quoting btwntx08:
finally wind is really blowing now extreme downpour


Should be getting pretty close to you man!!
Member Since: Posts: Comments:
For those of you wanting to know, but unable to watch. Boise just turned it over on their own 27. 9:16 left in the third qtr, 20-14 BSU
I really can't wait till we pass gas..ton.
Member Since: Posts: Comments:
Quoting hydrus:
African wave lookum angry..


Yes. That wave is embedded in a lot of moisture. The most this season for an African wave.
Member Since: Posts: Comments:
Quoting 954FtLCane:

lol trauma you're awesome dude, I always like reading your post..... Donuts please?


NO MORE DONUTS!!! THIS BLOG GOES CRAZY DURING THE NIGHT SHIFT ON SUGAR!!!
Member Since: Posts: Comments:
Quoting F4PHANTOM:
Yea, alot of dry air in the Atlantic

The dry air in the Atl. is the one thing that has prevented the explosion we expected for 2010. So far.
I wonder if it will change soon?
Member Since: October 24, 2005 Posts: 0 Comments: 24676
Quoting traumaboyy:


I worked down there cleaning up a bit after WILMA...and all I remember were those huge A$$ Mosquitoes that chewed through my screen windows and broke into the refrigerator and eat up all the Hot Dogs!!! The rain can not be helping your mosquito population!!


lol trauma you're awesome dude, I always like reading your post..... Donuts please?
Member Since: Posts: Comments:

Viewing: 936 - 886

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 | 34Blog 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
43 °F
Overcast