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: 186 - 136

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

Hey Guys!

So that area to the south and southwest of Hermine was a Dry slot. I though it was about 1-3 hours ago, but didn't mention it.
Member Since: Posts: Comments:
185. IKE
Brownsville,TX airport had a 48 mph wind gust on June 30th from Alex. You get that much wind in a severe thunderstorm.


Quoting skkippboo:
Why don't you like Bastardi?


He said on the Florida Network News(radio), back in August of 2005 that Katrina was headed for the Florida panhandle. Then when the models switched west to Louisiana he said, on FOX news, that his track was to Louisiana all along.

He stretches the truth.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting Krycek1984:


It's nothing but a fart in the wind right now...


Wasn't that a song by Kansas?
Member Since: Posts: Comments:
Quoting PrivateIdaho:


not to mention the amount of rain that will fall if the coc stays over water and stationary for any significant amount of time.

Mexico would get flooded. AGAIN.
Member Since: Posts: Comments:


Good afternoon!
Member Since: Posts: Comments:
He doesn't count landfalls, he counts impacts and he has said that straight up from the beginning. As long as he is telling you how he is evaluating himself ahead of time - he gets to make his rules. You may not agree with his rules and then you can ignore him and his self-evaluation. But he has set the way he will evaluate himself and that's how he will grade himself. If he was stressing landfall, he might have a whole different set of numbers.
Member Since: Posts: Comments:
Quoting skkippboo:
Why don't you like Bastardi?


Um last I checked it would be an impact on Brownsville if they receive TS force winds

Also looking at the forecast wind for Brownsville, it will easily see TS force winds
Member Since: Posts: Comments:
Quoting angiest:
Anyone else impressed with the strength of Hermine's convection?

I'm impressed on how quickly she consolidated.
Member Since: Posts: Comments:
Quoting WeatherNerdPR:

She wants to be called a hurricane so she's doing everything she can to be one. The longer the stall, the more likely the possibility of her being the 4th hurricane of the season.


not to mention the amount of rain that will fall if the coc stays over water and stationary for any significant amount of time.
Member Since: Posts: Comments:
Quoting IKE:


Then he'll say Hermine is an impact if Brownsville gets a tropical storm wind or gust.

Bastardi:(
Why don't you like Bastardi?
Member Since: Posts: Comments:
Quoting RecordSeason:
Lol.

Right now, Gaston is in such terrible shape, it barely even shows up on Radar even though it SHOULD be in range...

Antilles Radar


It's nothing but a fart in the wind right now...if you listen to some of the fanboys on here, Gaston would have been back to a TD/TS at least 3 times in the last few days ::rolls eyes:: Henny Penny, the sky is falling!
Member Since: Posts: Comments:
Anyone else impressed with the strength of Hermine's convection?
Member Since: Posts: Comments:
Quoting Thundercloud01221991:
recon confirms the stall at least mostly stall is shows very little movement

She wants to be called a hurricane so she's doing everything she can to be one. The longer the stall, the more likely the possibility of her being the 4th hurricane of the season.
Member Since: Posts: Comments:
Quoting RotorYacht:


Negative... I have a magic eight ball and it says YES. Not sure what to make of it though. Yes it will die or yes it will live.


..better ask it again... :^)
Member Since: Posts: Comments:
24.7N 97.2W looks like another center fix

what is that compared to the last vortex message?
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Did he say landfall? No, he said impact. Both Earl and Alex impacted the US by bringing tropical storm conditions to both of the areas both of those storms impacted.



Link
Member Since: Posts: Comments:
165. IKE
Quoting MiamiHurricanes09:
Did he say landfall? No, he said impact. Both Earl and Alex impacted the US by bringing tropical storm conditions to both of the areas both of those storms impacted.


Then he'll say Hermine is an impact if Brownsville gets a tropical storm wind or gust.

Bastardi:(
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting btwntx08:
get it right ppl either way im gonna get bad part of her


Please stop with me, me, me, me, etc.
Member Since: Posts: Comments:
Quoting Sfloridacat5:
Here's the loop that I've been using that shows slow movement.
http://radar.weather.gov/ridge/radar.php?rid=BRO&product=N0R&overlay=11101111&loop=yes
I think the orientation of the heavy thunderstorms from the north side of the center to the west side gives the impression of westerly movement. I zoomed in and then rocked back and forth between first and last frame. I just saw the slightest northward movement and no real westward movement at all. Of course all of this means nothing as she could decide to go due west from now until landfall and it wouldn't be that big of a surprise...
Member Since: Posts: Comments:
Quoting hydrus:
I think Gast-on has past-on...just kidding..:)


Negative... I have a magic eight ball and it says YES. Not sure what to make of it though. Yes it will die or yes it will live.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Did he say landfall? No, he said impact. Both Earl and Alex impacted the US.


It clearly says impact and not landfall too lol
Member Since: Posts: Comments:
recon confirms the stall at least mostly stall is shows very little movement
Member Since: August 1, 2006 Posts: 28 Comments: 3716
Quoting PtownBryan:


Between all of us and some others we got texas covered lol. Where are you San Antonions and Austinites? lol
Donna, TX. Waiting for the rain again!!!
Member Since: Posts: Comments:
Quoting ozzyman236:
houston needs to be paying attention to hermine...


Did they move Houston south of Brownsville?
Member Since: Posts: Comments:
156. IKE
Quoting angiest:


Meh, Alex brought TS conditions to Texas, and Earl did bring TS conditions to C, at least.


Agree....but, Earl came no closer than 75 miles from a USA landfall. About the same with Alex. If he's gonna play the game that way, then I quit playing his prediction.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Ok it looks like Hermine may have executed a very tight anticyclonic loop in the last 1.5 hours. Net movement from my first center fix to most recent scan was 6.2nm at 320 degrees.
Member Since: Posts: Comments:
It is clear that an element of uncertainty surrounds the eastern Caribbean Sea with
respect to forecasting the intensity and subsequent development of tropical disturbances
and weaker tropical cyclones. Due to this uncertainty, there have been many cases when
forecasters have maintained the status quo of a disturbance traveling through the eastern
Caribbean Sea – even if conditions appear favorable for development – only to forecast
its re-intensification once it leaves the region. This study investigates the possible
climatological factors that may be contributing to this local minimum of tropical
cyclogenesis. Since the vast majority of tropical cyclones that develop or enter the
eastern Caribbean region eventually affect surrounding islands or landmasses, including
the United States, it is imperative that forecasters understand the factors that may be
contributing to the unexpected weakening of nascent tropical cyclones in the eastern
Caribbean.
Member Since: Posts: Comments:
Quoting IKE:


Sorry Joe...Earl didn't make landfall in the USA.

Sorry Joe...Alex didn't make landfall in the USA.

Those 2 shouldn't count on your total of 8 USA impacts(Bastardi prediction). Your total should be one.
Did he say landfall? No, he said impact. Both Earl and Alex impacted the US by bringing tropical storm conditions to both of the areas both of those storms impacted.
Member Since: Posts: Comments:
Its a good thing Herm didnt have any more time over water...That thing ramped up quick.
Member Since: Posts: Comments:
looking at GRlevel3 I placed a marker at the lightest DBZ on the radar 1 hour ago and it has moved 2 NM in the last hour so I do agree with the present stall .... I wonder if the high is breaking down fast and we could see it turn N and then NE sooner maybe even over water???

evening everyone....yeah i was kinda wondering this myself....look at those past few frames on that radar and it looks like it might want to go more norhterly...but it's just my 2cents worth...lol
Member Since: Posts: Comments:
Quoting IKE:


Sorry Joe...Earl didn't make landfall in the USA.

Sorry Joe...Alex didn't make landfall in the USA.

Those 2 shouldn't count on your total of 8 USA impacts. Your total should be one.


Meh, Alex brought TS conditions to Texas, and Earl did bring TS conditions to C, at least.
Member Since: Posts: Comments:
Plenty of moisture in this part of the world now... ..........................I am sure this area is about to explode with activity.
Member Since: Posts: Comments:
Quoting PtownBryan:


Between all of us and some others we got texas covered lol. Where are you San Antonions and Austinites? lol



Bay City Area here!!
Member Since: Posts: Comments:
144. IKE
Quoting hurricanealley:
From Bastardi's Twitter account.

"So far 4 impact storms on US ( one, earl was a double) but only one hurricane impact, Earl on NC coast ( 2 total) others: Alex, Bonnie"

Link



Sorry Joe...Earl didn't make landfall in the USA.

Sorry Joe...Alex didn't make landfall in the USA.

Those 2 shouldn't count on your total of 8 USA impacts(Bastardi prediction). Your total should be one.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Yep she just took a sharp left turn.
Member Since: Posts: Comments:
Houston casting - that's a new one.
Member Since: Posts: Comments:
Quoting Thundercloud01221991:
looking at GRlevel3 I placed a marker at the lightest DBZ on the radar 1 hour ago and it has moved 2 NM in the last hour so I do agree with the present stall .... I wonder if the high is breaking down fast and we could see it turn N and then NE sooner maybe even over water???


That is how I am trcking the movement, or lack thereof.
Member Since: Posts: Comments:
Quoting IKE:
Landfall is within an hour or 2......



Definately shows a steady movement towards the coast.
Member Since: Posts: Comments:
Quoting wunderkidcayman:
I think that you guys have really overcasting the downcasting to the max with Gaston I am going to watch it tonight and into morning yes Gaston is in the hospital and is starting to come out of critical conditions and you know when that happens they don't look good at first but a few hours or a couple of days later they look really really good so don't let it fool you deathcaster/downcasters and the rest of ya because then ya all become the deatheaters/downeaters of crow and a lot of crow


I believe you are crowcasting! :^)
Member Since: Posts: Comments:
From Bastardi's Twitter account.

"So far 4 impact storms on US ( one, earl was a double) but only one hurricane impact, Earl on NC coast ( 2 total) others: Alex, Bonnie"

Link

Member Since: Posts: Comments:
I am thinking a Mexico landfall but it moves off shore NE of Brownsville and then moves NE across part of the gulf to like Houston area
Member Since: August 1, 2006 Posts: 28 Comments: 3716

Viewing: 186 - 136

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.