Hurricane watches for Mexico and Texas as Hermine suddenly develops

By: Dr. Jeff Masters , 4:15 PM GMT on September 06, 2010

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Hurricane watches are up for the Texas/Mexico border region as fast developing Tropical Storm Hermine steams towards the coast at 13 mph. Hermine was a tropical depression twelve hours ago, got its name just six hours ago, but already is a threat to intensify into a hurricane by tonight. It's remarkable how fast Gulf of Mexico disturbances can blow up into strong tropical storms, when the right mix of warm waters and low wind shear develops. Indeed, water temperatures are a very warm 30°C, wind shear is a low 5 - 10 knots, and the atmosphere is very moist in the Gulf--ideal conditions for a tropical storm. 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 moved ashore over southern Texas and northern Mexico, with radar estimated rainfall amounts already exceeding two inches in a few areas along the coast. Radar loops show that an eyewall may be beginning to form, and I expect this process will continue through the afternoon and early evening. Satellite imagery shows that Hermine is getting more organized, with vigorous thunderstorms with very cold tops building, low-level spiral bands developing, and improving upper-level outflow occurring on all sides except the west. There is some dry air to the west of Hermine over land that is restricting the storm's development there.

Forecast for Hermine
Hermine doesn't have much time over water before it comes ashore, which is a good thing. Hermine is organizing rapidly, and has a shot at reaching hurricane strength before the center moves ashore late tonight, near midnight. Neither the GFDL or HWRF models develop Hermine into a hurricane, but the HWRF model does predict that tropical storm force winds of 39+ mph will affect the coast as far north as Corpus Christi, Texas. 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. Early afternoon radar image of Tropical Storm Hermine.

Gaston continues to suffer from dry air
The remains of Tropical Storm 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 late this afternoon and continuing into the night. A pass from the ASCAT satellite this morning at 9:03 am EDT showed a large region of 25 mph winds on the north side of Gaston's circulation, and these winds will move into the northern Lesser Antilles late this afternoon. 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. Gaston does have developed a well-organized surface circulation, but not enough heavy thunderstorm activity to be considered a tropical depression. A large amount of dry air surrounds Gaston's remains on all sides, as seen on water vapor satellite loops.


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

Forecast for Gaston
Dry air will continue to be the major impediment to development for Gaston, 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 it 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. The models don't give much support for Gaston surviving past Wednesday, since many of them have the storm hitting the rugged island of Hispaniola, disrupting the storm.

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, the Turks and Caicos Islands, and Jamaica Wednesday night and Thursday morning. Though none of the global dynamical computer models are showing this, should Gaston survive the dry air and its coming encounter with Hispaniola, the storm will find itself in a very favorable environment for development in the Western Caribbean late in the week, and could intensify into a hurricane by next weekend.

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, and let's hope it doesn't live up to its fearsome-sounding name!

Next post
There will be an update by early this evening.

Jeff Masters

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1007. Skylink
Please check out the these webcams of South Padre, also let me know if there are any more to add

click here Link
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1006. angiest
Quoting spotted123:
Just north of Corpus in Rockport,tide is up 8 to 10 in. already.


Rockport is on the Aransas Bay system (Copano Bay) and not directly on the coast. There are some islands further out.

Man I wish we had gone down there yesterday.
Member Since: August 26, 2006 Posts: 16 Comments: 4766


Gaston, while still modest, is looking happier with himself atm.
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bermuda, please dont start the wishcasting today =/
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Wo!
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1001. Patrap
NEXRAD Radar
Brownsville, Storm Relative Mean Radial Velocity 0.50 Degree Elevation Range 124 NMI


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BDADUDE DUDE YOUR NOT NICE WISHCASTER JUST BECAUES YOU ARE DOSEN'T MEAN THAT EVERYONE IS

THAT IS DOWN RIGHT UNCALLED FOR
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Quoting Cotillion:
I said about 5.30-6pm (EDT) earlier...

Wonder how far out it'll be.

It's a west wobble from landfall.


Faster motion = less flooding. I'll take that, since that's the main concern with Hermine at this point.
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998. xcool
big waves
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Hi! Pearland, TX here. We're getting some rain. My plants are happy. I'm just hoping that we don't get a months worth of rain in the next few days.
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Brownsville will be affected by some strong spiral bands within the next 15 minutes.
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woah! luckily she's close to land.
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10 Bucks a year gets one 40 frames..all da time.

Money well spent to support the wunderground.
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Just north of Corpus in Rockport,tide is up 8 to 10 in. already.
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Patrap, thanks for finding a 3-hr radar loop. The greater perspective really helps.
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10 PM



1 am



4 am
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Quoting moonlightcowboy:


AVN LOOP




Some good "reds" popping now over Gaston's coc. We'll see if he can hang on to them. Position is likely now far enough south of Earl and Fiona's wake that he might finally be getting into some warmer, deeper waters that will allow him to create enough moisture lift faster than the ULL to its west can steal it. ;)


You probably dont live in the islands... ?
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Quoting futuremet:


BDADUDE has been wishcasting Gaston since last night. He insists that it will somehow spontaneously move north near Bermuda.


FUTUREMET HAS BEEN FUTUREMET/CASTING FROM DAY "1"
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I said about 5.30-6pm (EDT) earlier...

Wonder how far out it'll be.

It's a west wobble from landfall.
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982. xcool
wind pick up bigtime on webcam.
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NEXRAD Radar
Brownsville, Base Reflectivity 0.50 Degree Elevation Range 124 NMI


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Quoting MiamiHurricanes09:
+500. Many here are always judging someone else. Seriously, who cares what type of caster they are.


and usually those who judge someone else on their opinions, either do not have one of their own or do not know enough to formulate one of their own; hence why they troll in the first place.
Member Since: March 10, 2010 Posts: 1 Comments: 7726
979. xcool
MiamiHurricanes :)
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The NHC seems to have a good handle on where Hermine will go and what she will do
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Quoting TexInsAgent:


Please tell me what that is


We don't want to get banned. Just rent "Full Metal Jacket".
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976. mobal
Regardless of where this cyclone hits, MX or TX. Regagardless if it is a small cat one or TS. The Reo Grande valley will have flooding issues. All of the containment plans will not work. The lakes (Falcon etc.) are at capacity, and they have drained more today which will most likely only add to the problem (flooding down stream). All those in the RGV, stay high and dry! To my friends in Reynosa and McAllen, good luck!
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Quoting btwntx08:
nws says 70 mph gusts but i think i might see 75-80 mph gusts maybe
I think you are right.
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Quoting ozzyman236:
i think its possible for hermine to go all the way up to houston before officially moving inland...


I think that's not possible.
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Quoting FLdewey:
Only two things come from Texas...


Please tell me what that is
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970. xcool
i have best webcam for Brownsville wow
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Based on this radar, landfall is coming fast.

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Quoting xcool:
who give beep beep if someone is wishcasting god i'm very tired hear about .
+500. Many here are always judging someone else. Seriously, who cares what type of caster they are.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
967. code1
Gonna quote Patrap here (first time ever!). "Calamity knows no borders, only small minds do", or something like that. Goes for all wishcasters, downcasters, etc. Can't we just all watch, learn, voice opinions? If I voiced mine? None would call me any of the above. Just STUPID would be what I would hear on these storms. More of us lurkers rely on those of us we choose to do so with. Doesn't matter who turns out to be wrong or right, it's human nature. For me? I wish no one area landfall, while wishing for another Earl to watch. Amazing he was!
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Hot Towers over ex Gaston COC, if that keeps up, he might just pull it off :)
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Alright-Time out...Whatever it is your doing, Stop, go to the fridge, grab a beer. Drink. BE NICE...Its a holiday.
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Quoting BDADUDE:
That is a down and out lie. Not nice dude! I said it was going to head towards the Bahamas and skirt Florida. Pay attention next time!!


LMAO!

I know at least two times where you said that it would affect Bermuda!
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GOM IR Loop

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gaston forecast tracks & intensity models
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brownsville about to get slammed with a band of heavy wind
Member Since: April 17, 2010 Posts: 0 Comments: 1753
Quoting ozzyman236:
a nnw movement usually the hurricanes that hit brownsville move wnw this isnt happening it leaves and alley way for the storm to go up the texas coast...i would not let your guard down you will see when it touches the land area..
is almost over land!lol
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Our NWS here in Fort Worth is calling for 2-4 inches of rain, with the possibility of 6 inches or more...Wow.
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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.