Ernesto Dissipates Over Mexico

Tropical Weather Discussions and Analysis
Post Reply
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

The GFS along with the Canadian have been rather robust suggesting development of the disturbance also known as Pouch 10 by the Montgomery Group. The 00/06 Z GFS insists that 850mb vorticity increases as the system nears the Caribbean Islands in about 100 hours at a fairly low latitude and traverses to Caribbean. We will see.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

The GFSE are more suggestive of development further W in the Western Caribbean near the Yucatan where conditions would tend to be more favorable in the longer range. Other than increased moisture, I tend to think Florida is safe with this one. In fact several members suggest the NW Gulf may be the area to watch for any future development. We will see.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT MON JUL 30 2012

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A TROPICAL WAVE...ACCOMPANIED BY A WEAK AREA OF LOW PRESSURE LOCATED
ABOUT 800 MILES SOUTHWEST OF THE CAPE VERDE ISLANDS...IS PRODUCING
AN AREA OF DISORGANIZED SHOWERS AND THUNDERSTORMS. ENVIRONMENTAL
CONDITIONS APPEAR CONDUCIVE FOR SOME GRADUAL DEVELOPMENT OF THIS
SYSTEM OVER THE NEXT FEW DAYS. THIS SYSTEM HAS A LOW CHANCE...20
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS
AS IT MOVES WESTWARD AT 10 TO 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BRENNAN
Attachments
07302012_1115_msg2_x_vis2km_99LINVEST_20kts-1010mb-97N-343W_100pc.jpg
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

The 06Z HWRF which has be performing better this season since some major upgrades to that Hurricane model suggest a weak system nearing the Islands in 126 hours at a lower latitude than the GFDL which does tend to favor what the ensembles are sniffing.
Attachments
07302012 06Z HWRF uv900_mslp_p_43.png
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

The 12Z Euro has picked up on 99L and now has a disturbance tracking through the Caribbean albeit weak and ending up in the Western Caribbean in about 7-8 days or so...
Attachments
07302012 12Z Euro 12zeurotropical850mbVortSLP168.gif
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
wxman57
Global Moderator
Global Moderator
Posts: 2621
Joined: Thu Feb 04, 2010 5:34 am
Location: Southwest Houston (Westbury)
Contact:

srainhoutx wrote:The 12Z Euro has picked up on 99L and now has a disturbance tracking through the Caribbean albeit weak and ending up in the Western Caribbean in about 7-8 days or so...
Euro also moves it extremely quickly - I think way too fast.
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

wxman57 wrote:
srainhoutx wrote:The 12Z Euro has picked up on 99L and now has a disturbance tracking through the Caribbean albeit weak and ending up in the Western Caribbean in about 7-8 days or so...
Euro also moves it extremely quickly - I think way too fast.

Yep...I agree. That said a weaker system would tend to favor a W to WNW track through the Caribbean into the W/NW Caribbean in about 10 days or so. Not sure I'm buying the NW trend of the GFS and its ensembles as they are developing this disturbance way too quickly, IMO.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
Ptarmigan
Statistical Specialist
Statistical Specialist
Posts: 3982
Joined: Wed Feb 03, 2010 7:20 pm
Contact:

This should get interesting. If conditions are right, it could be Ernesto. The sooner 99L develops, the more likely it is a fish storm. The later it develops, the more likely it will make landfall in the Caribbean and North America.
Andrew
Site Admin
Site Admin
Posts: 3438
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

Euro suggests things will get pretty active in the extended range with a storm in the gulf, Atlantic and another wave coming off the African coast (granted it is hour 240 so things can change a lot by then). Mid level ridging really seems to develop in the next couple of weeks over the central/ northern Atlantic according to the gfs and euro. As a result this would help push any storms farther west into the gulf. Looking at shear though current analysis along with projected shear shows the Caribbean as a very hostile place with 20-30+ knot winds. That looks to be the reasoning behind the gfs when it looses it in the longer range . CMC develops 99L faster than any other model which doesn't look as realistic with the amount of shear and SAL around it. Track is further north with the cmc but i suspect with ridging developing to the north and east it could push it farther west into the gulf. Also keep an eye on MJO as models are now predicting a phase 1 or 8 transition over the next couple of weeks. This could further enhance storms right in the middle of the season.

EURO 240h:
00zeurotropical850mbVortSLP240.gif
Canadian 144h:
00zggemtropical850mbVortSLP144.gif
MJO:
combphase_noCFSfull.gif
SAL East Atlantic:
splitE.jpg
Shear:
wg8shr.GIF
MIMIC (microwave of moisture or TPW):

Image
For Your Infinite Source For All Things Weather Visit Our Facebook
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Morning e-mail from Jeff concerning the Tropics and 99L:

Atlantic basin tropical activity appears to be entering into a more active period over the next several week.

As is normal for this time of year, the Atlantic basin tropical activity usually shows an upswing in activity starting in early August. Factors over the Atlantic basin do suggest that the potential for tropical cyclone formation will be increasing over the next several weeks in part due to climatology and in part due to increasingly favorable atmospheric factors within the basin. Tropical waves leaving Africa are slightly more well defined and robust, stable and dry African air moving westward off Africa is slowly subsiding, a fairly favorable MJO pulse will be moving into the basin over the next 2 weeks. Forecast models are resolving these increasingly favorable factors with increasing tropical activity. However one must remember that we are borderline ENSO warm (El Nino) in the Pacific and this can negate development in the Atlantic basin with increased wind shear even when all other factors are favorable.

99L:

A weak surface low pressure system located 1100 miles WSW of the Cape Verde Islands in remains embedded within the monsoon tropical across the central Atlantic basin. A review of water vapor images and Total PW images show a large envelop of deep tropical moisture with this feature and the surface trough protecting the surface low with dry air well to the north. Convection is overall disorganized and scattered near the feature and not centered or concentrated near the weak surface low, but off it its north and northwest. As is usual with systems tangled with the monsoon trough, slow development is possible, but the key word is slow!

Global forecast model support for this system is fairly good with nearly every model making it into a closed storm (exception the NOGAPS model which keeps it an open wave). Most of the guidance shows fairly quick development east of the Windward Islands, except the EURO which races the system westward barely keeping it a defined system. Nearly all of the guidance shows the system struggling after making it near/into the Caribbean and this is likely a factor of increased wind shear (either due to a possible fast forward motion or increasing upper level winds aloft). Feel the EURO is too fast on the westward motion and the CMC too far to the north and too strong. The system will likely continue a W to even WSW track for the next 2-3 days and gradually organize possibly into a tropical depression or even a tropical storm as it nears/approaches the Windward and Leeward Islands. After that there is much spread in the track and intensity guidance.

Does a Wet July suggest an increased threat of Texas tropical activity in August and September?

Chris Hebert of Impact Weather recently completed a study looking at the effects of the top 20 wettest and top 20 driest July’s and the impacts of tropical activity on the upper TX coast in August-November of that year. The results are seen in the graphic below and are fairly dramatic. For the 20 wettest July’s, 13 tropical storms impacted the NW Gulf following that wet July versus 9 in the top 20 dry years. Even more astounding is that 11 hurricanes impacted following a wet July with only 4 in the dry years and 8 major hurricanes impacted the NW Gulf versus none following a dry July. To sum up the data following a wet July, there is a greater than 50% chance a hurricane will strike the TX/LA coast.

The reasoning of this makes sense, as a wet July strongly indicates a lack of strong high pressure over TX (much like this summer) usually with a weakness or trough in the height field aloft in this region. Tropical systems approaching from the south and east will flow toward this weakness in the ridge…hence unlike in 2011 when Texas was strongly protected by strong high pressure, this year we are not and we will need to keep a very close eye on developments over the next 2 months.
Attachments
07312012 Jeff image001.jpg
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
Post Reply
  • Information
  • Who is online

    Users browsing this forum: No registered users and 37 guests