Hurricane watches for Mexico and Texas as Hermine suddenly develops

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

Share this Blog
2
+

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

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: 607 - 557

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23Blog Index

Quoting CycloneUK:
Awesome post CycloneUK.
Member Since: September 27, 2007 Posts: 1 Comments: 21507
Quoting Stormchaser2007:


He's talking about what it would take for it to be re-classified. Nothing more.

No need to attack him.
There is if you want to get quoted a bunch. A personal attack is a fairly reliable tell. If it walks like a . . .
Member Since: Posts: Comments:
Quoting txraysfan:
We live outside of Victoria-Port Lavaca is about 15 min away.


Gotcha not far from 59 then. Well hey neighbor!
Member Since: July 5, 2010 Posts: 0 Comments: 170
Quoting StormW:
Hey Shen!
Stormw what are your thoughts on the wave near africa.Could it turn out the way the GFS says it will.
Member Since: August 14, 2010 Posts: 10 Comments: 17164
Quoting centex:
Hermine is rather large weather system. We are getting weather change here in Austin which is over 400 miles from center.
big time rain event coming even after land fall with track ending OK.

Member Since: July 15, 2006 Posts: 174 Comments: 54639
601. JLPR2
Quoting CycloneUK:


Cool!
Member Since: September 4, 2007 Posts: 7 Comments: 8735
@MLC
So far, the tutt is moving in tandem with gaston to the wnw and is poised to vent him.
Member Since: Posts: Comments:
Quoting will40:


at least he didnt circumvent the ban enuff said


It seems he doesn't need to circumvent; many others are doing it for him, aren't they? ;-)
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting StormW:


Gaston has a surface trough extending from him to the northwest and there is speed-convergence there due to a burst of easterly wind on his northern side that becomes slower downstream. This causes the air to pile up which forces it to rise, causing the thunderstorms you see to the northwest of Gaston.

I'm not too sure on the surface trof...however, the TUTT to his west would have the effect Levi has mentiond...if you run a closer water vapor loop, as in the Caribbean loop or CATL loop, and then look at the CIMSS chart, you can see where the extreme western portion of the TUTT and outflow over him "meet" or converge.

LOOP




Thank you, StormW. TUTT? Southwest of Gaston in the eastern Caribbean? And, what seems to be upper level convection being pulled northwards by the ULL to Gaston's west (presently over Haiti)? Wouldn't that also mean that Gaston faces more shear as he enters the Caribbean?

Again, thanks.
Member Since: July 9, 2006 Posts: 184 Comments: 29610
Can Gaston die already......It's getting frustraiting
Member Since: August 14, 2010 Posts: 10 Comments: 17164
Pressure down to 1005.2mb as they continue to get closer to Hermine's circulation...however, they are still ways away from it.

185630 2437N 09611W 8430 01534 0052 175 145 157046 046 041 004 00
Member Since: September 2, 2009 Posts: 130 Comments: 21194
1005mb so far but nowhere near the center yet.


000
URNT15 KNHC 061856
AF301 0210A HERMINE HDOB 14 20100906
184700 2450N 09542W 8429 01550 0073 +177 +137 158042 043 037 004 00
184730 2449N 09543W 8430 01551 0072 +176 +141 158043 043 037 004 03
184800 2448N 09544W 8425 01554 0072 +175 +147 160043 044 037 003 03
184830 2448N 09546W 8429 01548 0070 +177 +143 159044 044 037 004 00
184900 2447N 09548W 8433 01544 0070 +175 +144 160044 044 037 005 00
184930 2446N 09549W 8429 01549 0070 +171 +150 160044 045 038 004 00
185000 2446N 09551W 8428 01549 0068 +174 +154 162040 042 039 005 00
185030 2445N 09552W 8430 01543 0068 +168 +165 160037 039 037 007 00
185100 2444N 09554W 8425 01548 0069 +165 //// 160041 043 039 008 01
185130 2444N 09555W 8429 01544 0066 +170 +152 163041 042 036 005 00
185200 2443N 09557W 8431 01542 0065 +170 +149 161041 042 038 005 00
185230 2442N 09558W 8431 01539 0063 +173 +148 157044 045 041 005 00
185300 2441N 09600W 8432 01540 0060 +177 +147 157045 046 042 004 00
185330 2441N 09602W 8431 01541 0060 +176 +142 158043 044 041 005 00
185400 2440N 09603W 8428 01543 0060 +174 +139 157045 046 041 003 00
185430 2439N 09605W 8429 01541 0060 +175 +143 157046 046 041 005 00
185500 2439N 09606W 8432 01537 0056 +174 +151 156043 045 041 005 00
185530 2438N 09608W 8432 01534 0057 +172 +159 155044 046 039 005 00
185600 2437N 09609W 8428 01538 0055 +174 +148 157045 045 040 005 00
185630 2437N 09611W 8430 01534 0052 +175 +145 157046 046 041 004 00
$$
;
Member Since: November 24, 2005 Posts: 635 Comments: 26661
Gaston is building some convection right now, but its that time of day for him to do it anyway. This batch of convection will likely die out like all the others, and I believe he will not get reclassified until tomorrow at the earliest.

Member Since: July 6, 2010 Posts: 113 Comments: 32354
Hermine is rather large weather system. We are getting weather change here in Austin which is over 400 miles from center.
Member Since: August 10, 2007 Posts: 0 Comments: 3289
Member Since: July 15, 2006 Posts: 174 Comments: 54639
589. Vero1
Member Since: Posts: Comments:
Reminder: this is a public forum, folks. If you have a question to ask that you wish only a certain person to answer, you'd be far better off sending that certain person a WU-mail message than asking in front of everyone. Either that, or wise up and realize that, so long as others are allowed to answer the questions they read, they're going to.
Member Since: Posts: Comments:
Quoting TXEER:


Think about what you wrote...


Quoting MiamiHurricanes09:
I would like to see it persist through the evening. Even if convection does increase now, it won't be worth anything if it just dissipates around sun set.

Calm down bro, he was only making an analisys, people on the islands are aware of Gaston development.
Member Since: Posts: Comments:
18z SHIPS

AL, 09, 2010090618, 03, SHIP, 0, 175N, 572W, 30, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 12, 173N, 601W, 33, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 24, 172N, 628W, 41, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 36, 172N, 653W, 50, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 48, 174N, 676W, 62, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 60, 176N, 695W, 73, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 72, 178N, 712W, 80, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 84, 182N, 728W, 87, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 96, 186N, 745W, 93, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 108, 191N, 764W, 102, 0, , 0, , 0, 0, 0, 0,
AL, 09, 2010090618, 03, SHIP, 120, 196N, 784W, 111, 0, , 0, , 0, 0, 0, 0,
Member Since: June 9, 2007 Posts: 4 Comments: 15923
weak west winds found down by 16.5N

not very convincing, Ex-Gastons' circulation is getting weaker
Member Since: March 10, 2010 Posts: 1 Comments: 7831
Quoting PtownBryan:


Where south? Enjoy! We have some pretty good strikes going on and heavy rain. Such a nice sight after the warmets August on record for Houston ever!
We live outside of Victoria-Port Lavaca is about 15 min away.
Member Since: July 17, 2010 Posts: 0 Comments: 2
From 263° at 8 knots
(From the W at ~ 9.2 mph)

theres ya W winds
Member Since: September 19, 2005 Posts: 2 Comments: 4251
Quoting Stormchaser2007:


Oz was banned from here.

Best not to really promote him or his site...otherwise you may suffer the same fate.


at least he didnt circumvent the ban enuff said
Member Since: September 19, 2005 Posts: 2 Comments: 4251
578. HadesGodWyvern (Mod)
site still has GASTON as a tropical low with winds of 30 knots.
Member Since: Posts: Comments:
I highly doubt Gaston is a TD or TS yet
Member Since: July 6, 2010 Posts: 113 Comments: 32354
Quoting TXEER:


Think about what you wrote...


Quoting MiamiHurricanes09:
I would like to see it persist through the evening. Even if convection does increase now, it won't be worth anything if it just dissipates around sun set.


He's talking about what it would take for it to be re-classified. Nothing more.

No need to attack him.
Member Since: June 9, 2007 Posts: 4 Comments: 15923
Quoting TXEER:


Think about what you wrote...


Quoting MiamiHurricanes09:
I would like to see it persist through the evening. Even if convection does increase now, it won't be worth anything if it just dissipates around sun set.
Ok? How does that tie in to what you wrote. Did I in any way say I was hoping for development?
Member Since: September 2, 2009 Posts: 130 Comments: 21194
574. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #33
SEVERE TROPICAL STORM MALOU (T1009)
3:00 AM JST September 7 2010
================================

SUBJECT: Category Two Typhoon in Sea around Tushima

at 18:00 PM UTC, Severe Tropical Storm Malou (985 hPa) located at 33.4N 127.9E has 10 minute sustained winds of 50 knots with gusts of 70 knots. The cyclone is reported as moving northeast at 9 knots

Dvorak Intensity: T3.0

Gale Force Winds
=================
180 NM from the center in southeastern quadrant
110 NM from the center in northwestern quadrant

Forecast and Intensity
========================
24 HRS: 35.5N 131.0E - 50 knots (CAT 2/Severe Tropical Storm)
48 HRS: 37.4N 138.6E - 40 knots (CAT 1/Tropical Storm)
72 HRS: 37.2N 146.8E - 35 knots (CAT 1/Tropical Storm)

Member Since: Posts: Comments:
Quoting txraysfan:
Am south of you, we've had 1 1/2 of rain so far


Where south? Enjoy! We have some pretty good strikes going on and heavy rain. Such a nice sight after the warmets August on record for Houston ever!
Member Since: July 5, 2010 Posts: 0 Comments: 170
Quoting Wariac:
I just saw the navy site an it has Gaston back up again....09LGaston...is it a TD or TS again?
I don't think so, nothing on ATCF site.
Member Since: August 10, 2007 Posts: 0 Comments: 3289
Quoting leo305:


I guess it's a TD.. but it could be a TS since it has those 40mph winds


I don't think its been re-activated.
Member Since: June 9, 2007 Posts: 4 Comments: 15923
Impressive on ASCAT....potent onshore SSE flow out of the Gulf of Mexico shows how much rain the northwest gulf coast is going to get out of this over a large area.

Member Since: November 24, 2005 Posts: 635 Comments: 26661
Quoting TXEER:


Heavens yes...let's hope for development so Gaston can hit land...destroy property and kill people...good grief some of you people!


LOL...que? are you serious? I don't see anybody suggesting that.
Member Since: Posts: Comments:
Quoting AllStar17:
Of course the Weather Channel is showing Storm Stories and there is a tropical system active and approaching land.
yes I stop watching them since they started to show storms stories during pick of hurricane season and when ever you turn the channel at the top of the hour. And when they do talk about the tropics they do it in such a hurry, is if like they are afraid they are going lose "sponsors" if the talk about it",specially from the stourist agencies.
Member Since: Posts: Comments:
Quoting Wariac:
I just saw the navy site an it has Gaston back up again....09LGaston...is it a TD or TS again?


I guess it's a TD.. but it could be a TS since it has those 40mph winds
Member Since: April 17, 2010 Posts: 0 Comments: 1753
Pressure down to 1007.3mb as they approach Hermine's circulation.

184630 2451N 09541W 8428 01553 0073 +176 +136 158041 041 036 002 00
Member Since: September 2, 2009 Posts: 130 Comments: 21194
TropicalStormHermine's heading had turned westward to (2.5degrees north of) NorthWest
from its previous heading of (2.3degrees west of) NorthNorthWest
TD.10's average speed moving between its last 2 reported positions was ~21.6mph(~34.9km/h)

Invest90L -- 6hour intervals between positions
05Sep . 06pmGMT - - 19.9n95.7w - - 25knots - - 1004mb - - NHC-ATCF *95.9w
06Sep . 12amGMT - - 20.4n9.54w - - 25knots - - 1003mb - - NHC-ATCF
TD.10 -- 3hour intervals between positions (including the previous one and the next)
06Sep . 03amGMT - - 20.7n95.2w - - 30mph - - 1003mb - - NHC.Adv.#1
06Sep . 06amGMT - - 20.9n95.0w - - 35mph - - 1003mb - - #1A
TD.10 becomes TS.Hermine
06Sep . 09amGMT - - 21.6n95.0w - - 40mph - - 1001mb - - #2
06Sep . 12pmGMT - - 22.4n95.3w - - 45mph - - - 995mb - - #2A
06Sep . 03pmGMT - - 23.4n95.8w - - 50mph - - - 998mb - - #3
06Sep . 06pmGMT - - 24.1n96.5w - - 60mph - - - 995mb - - #3A

25knots=~28.8mph __ ~26.1knots=30mph

Copy and paste 19.9n95.7w, 20.4n95.4w, 20.7n95.2w, 20.9n95.0w-21.6n95.0w, 21.6n95.0w-22.4n95.3w, 22.4n95.3w-23.4n95.8w, 23.4n95.8w-24.1n96.5w, mid, bro, 24.1n96.5w-25.38N97.8w into the GreatCircleMapper for a look at the last 12^hours.

Using straightline projection upon the speed&heading averaged
over the 3hours spanning the last two reported positions:
~4&1/2hours from now to LaGloria,Tamaulipas,Mexico

* Before the NHC reevaluated&alterered the ATCF numbers.
^ The dots preceeding the four line segments show positions that were measured 6hours apart
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
GR2AE also shows that Hermine has indeed become better organized recently.


Yep.

Looks like the core has become better defined.

Member Since: June 9, 2007 Posts: 4 Comments: 15923
Gaston....

Member Since: Posts: Comments:
I just saw the navy site an it has Gaston back up again....09LGaston...is it a TD or TS again?
Member Since: Posts: Comments:
Quoting TXEER:


Heavens yes...let's hope for development so Gaston can hit land...destroy property and kill people...good grief some of you people!
What are you talking about?
Member Since: September 2, 2009 Posts: 130 Comments: 21194

Viewing: 607 - 557

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23Blog 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.