Tropical Storm Gaston

[Paranoid]

98L has become TD9. Forecast to become Gaston and could potentially end up heading into the Gulf via the Caribbean. One to keep an eye on.

000

WTNT34 KNHC 011453

TCPAT4

BULLETIN

TROPICAL DEPRESSION NINE ADVISORY NUMBER 1

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092010

1100 AM AST WED SEP 01 2010

...ANOTHER TROPICAL DEPRESSION FORMS IN THE EASTERN ATLANTIC...

SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION

-----------------------------------------------

LOCATION...12.4N 35.8W

ABOUT 830 MI...1335 KM WSW OF THE CAPE VERDE ISLANDS

ABOUT 1720 MI...2770 KM E OF THE LESSER ANTILLES

MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/HR

PRESENT MOVEMENT...W OR 275 DEGREES AT 15 MPH...24 KM/HR

MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES

WATCHES AND WARNINGS

--------------------

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

DISCUSSION AND 48-HOUR OUTLOOK

------------------------------

AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL DEPRESSION NINE

WAS LOCATED NEAR LATITUDE 12.4 NORTH...LONGITUDE 35.8 WEST. THE

DEPRESSION IS MOVING TOWARD THE WEST NEAR 15 MPH...24 KM/HR. THE

CYCLONE SHOULD MOVE TOWARD THE WEST OR WEST-NORTHWEST AT A SLOWER

FORWARD SPEED DURING THE NEXT TWO DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER

GUSTS. SOME STRENGTHENING IS FORECAST AND IT IS LIKELY THAT THE

CYCLONE WILL BECOME A TROPICAL STORM DURING THE NEXT 48 HOURS.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.

HAZARDS AFFECTING LAND

----------------------

NONE

NEXT ADVISORY

-------------

NEXT COMPLETE ADVISORY...500 PM AST.

$$

FORECASTER LANDSEA/BLAKE

[Somerset Squall]

Conditions don't look all that great ahead of 09L, there appears to be some shear and more importantly, quite a lot of dry air as SAL comes into play. But I agree with NHC that some slow intensification seems possible.

[Cookie]

Just over 2 weeks into the peak of the season and the names are racking up, won't be long till this a TS

[Iceberg]

Again this is another strange one, GFS and ECM have finally taken a shine on this after ignoring him and both make him Hurricane Gascon, but with very different paths, definately one to watch.

[Paranoid]

Now TS Gaston. Thread name change if you please mods =).

Forecast to become a hurricane in about 4 days time once shear abates.

000

WTNT34 KNHC 012040

TCPAT4

BULLETIN

TROPICAL STORM GASTON ADVISORY NUMBER 2

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092010

500 PM AST WED SEP 01 2010

...THE SEVENTH NAMED STORM OF THE SEASON FORMS...THE FOURTH TROPICAL

STORM IN THE LAST ELEVEN DAYS...

SUMMARY OF 500 PM AST...2100 UTC...INFORMATION

----------------------------------------------

LOCATION...12.9N 37.0W

ABOUT 895 MI...1440 KM WSW OF THE CAPE VERDE ISLANDS

ABOUT 1635 MI...2635 KM E OF THE LESSER ANTILLES

MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/HR

PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/HR

MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES

WATCHES AND WARNINGS

--------------------

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

DISCUSSION AND 48-HOUR OUTLOOK

------------------------------

AT 500 PM AST...2100 UTC...THE CENTER OF TROPICAL STORM GASTON WAS

LOCATED NEAR LATITUDE 12.9 NORTH...LONGITUDE 37.0 WEST. GASTON IS

MOVING TOWARD THE WEST NEAR 15 MPH...24 KM/HR. A WEST OR

WEST-NORTHWEST MOTION WITH A SIGNIFICANT DECREASE IN FORWARD SPEED

IS EXPECTED FOR THE NEXT SEVERAL DAYS.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 40 MPH...65

KM/HR...WITH HIGHER GUSTS. SLOW STRENGTHENING IS FORECAST DURING

THE NEXT 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM

FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB...29.68 INCHES.

HAZARDS AFFECTING LAND

----------------------

NONE

NEXT ADVISORY

-------------

NEXT COMPLETE ADVISORY...1100 PM AST.

$$

FORECASTER BLAKE

[mrpsb]

TS Gaston is born!

Now I have to try to get that song from Disney's Beauty and the Beast out of my head.

edit: He's come a long way since being a 10% chance yesterday

[Iceberg]

Already NHC have upped him to Tropical Storm Gaston.

They make him a hurricane in the future as well !

TROPICAL STORM GASTON FORECAST/ADVISORY NUMBER 2

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092010

2100 UTC WED SEP 01 2010

Track is heading for the Caribbean.

[Paranoid]

The caribbean has been pretty much untouched this season (apart from Alex briefly in June). I dont think shear levels are anything spectacularly high atm in the area and SSTs are around 29-30c. Could end up becoming a major hurricane so this one should be watched as a potential threat.

[summer blizzard]

I agree with the models in regards to Tropical Storm Gaston becoming a Hurricane, possibly even a major one, however i think that the track will be similar to Hurricane Danielle because Tropical Storm Gaston is not close enougth to Hurricane Earl and Tropical Storm Fiona to take advantage of the steering currents, could hit the eastern USA, but doubtful.

[AderynCoch]

Definitely the potential for Gaston to become a problem in a few days time, with ridging currently expected to stop the system travelling too far north. Could already be a major hurricane by the time it approaches the Lesser Antilles.

[Somerset Squall]

Gaston's intensity has remained at 35kts, and it appears the storm is suffering from dry air filtrating into the circulation. Convection appears a little patchy this afternoon, though the LLC still seems well defined. Interesting to note that Gaston has slowed to a crawl; he is moving westwards at just 8kts, which is much slower than average. Gaston could slow further as a trough replaces the ridging to the north. Evetually, ridging should build back in and increase Gaston's track speed, but it appears Gaston will be moving on a much more southerly track than Danielle, Earl and Fiona...

[Paranoid]

Gaston has dissipated, a little unexpectedly but given conditions its not a huge surprise. Could regenerate but NHC forecast it to stay as a non-tropical system from now.

000

WTNT44 KNHC 022033

TCDAT4

TROPICAL DEPRESSION GASTON DISCUSSION NUMBER 6

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092010

500 PM AST THU SEP 02 2010

CONVENTIONAL SATELLITE IMAGERY AND DROPSONDES FROM THE NATIONAL

SCIENCE FOUNDATION G-V AIRCRAFT INDICATE THAT GASTON HAS

DEGENERATED INTO A REMNANT LOW PRESSURE AREA. THE SYSTEM CONSISTS

OF A WEAK LOW-LEVEL CIRCULATION WITHOUT ORGANIZED DEEP CONVECTION.

MAXIMUM WINDS ARE ESTIMATED TO BE 25 KT...AND THESE WINDS ARE LIKELY

OCCURRING ONLY IN A SMALL AREA OF SHOWERS WELL TO THE NORTH OF THE

CENTER.

THE REMNANT LOW IS SITUATED TO THE SOUTH OF A WEAKNESS IN THE

SUBTROPICAL RIDGE...AND IS DRIFTING WESTWARD. THE LARGE-SCALE

MODELS PREDICT SOME BUILDING OF RIDGE TO THE NORTH OF THE CYCLONE

OVER THE NEXT FEW DAYS. THEREFORE...THE OFFICIAL FORECAST TRACK

INDICATES A CONTINUED GENERAL WESTWARD MOTION WITH A GRADUAL

INCREASE IN FORWARD SPEED.

ALTHOUGH NOT EXPLICITLY INDICATED HERE...THERE IS A POSSIBILITY THAT

GASTON COULD REGENERATE INTO A TROPICAL CYCLONE DURING THE FORECAST

PERIOD. THIS IS THE SCENARIO THAT IS BEING SUGGESTED BY SOME OF THE

GLOBAL MODELS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 02/2100Z 13.5N 39.5W 25 KT

12HR VT 03/0600Z 13.5N 40.4W 25 KT...POST-TROP/REMNT LOW

24HR VT 03/1800Z 13.7N 41.7W 25 KT...POST-TROP/REMNT LOW

36HR VT 04/0600Z 14.0N 43.0W 25 KT...POST-TROP/REMNT LOW

48HR VT 04/1800Z 14.2N 44.4W 25 KT...POST-TROP/REMNT LOW

72HR VT 05/1800Z 14.5N 48.0W 25 KT...POST-TROP/REMNT LOW

96HR VT 06/1800Z 15.0N 52.5W 25 KT...POST-TROP/REMNT LOW

120HR VT 07/1800Z 15.5N 57.5W 25 KT...POST-TROP/REMNT LOW

$$

FORECASTER ROBERTS/PASCH

[AderynCoch]

I must say I'm surprised by how quickly Gaston has been ripped apart - was dry air really that abundant?

Anyhow, the remnants are still worth watching.

[AderynCoch]

Chance of reforming up from 10% (Low) to 40% (Medium).

Most of the models send the system towards the Leeward Islands.

[Somerset Squall]

Up to 50% chance of re-formation now. Convection isn't amazing but it certainly slowly building again. LLC remains well defined.

[Iceberg]

Gaston has a very good LLCC, but convection is struggling to last the 24 hrs of the diurnal cycle. Gaston has ALOT of dry air to punch through on it's way to the Caribbean outer islands. Once their conditions should improve.

IF you want Gaston to survive (and many in the Caribbean don't) then this up and down in convection is probably enough to keep the LLCC intact for a few days until things improve, 24 hrs without convection and Gaston will really be struggling.

[summer blizzard]

http://www.ssd.noaa.gov/goes/flt/t3/vis-l.jpg

Beautiful system, strong circulation but convection clearly sparse.

http://www.ssd.noaa.gov/goes/east/tatl/wv-l.jpg

Conditions should improve in the next 24-48 hours which is probably why the NHC have upped the chance of development to 70%, however any northward movement is going to send it north of the Islands, especially if it does develop, as such Cuba, the Bahamas and Florida should all keep a close eye.

Could somebody post the predicted track?

[Iceberg]

As requested.

[summer blizzard]

Track certainly up in the air then, though i think a Bahamas/Florida track is the more likely.

[Rob]

Shouldn't be long before NHC begin issuing adivsories for Gaston again, tomorrow morning at the latest i would say.

[summer blizzard]

Shouldn't be long before NHC begin issuing adivsories for Gaston again, tomorrow morning at the latest i would say.

Upto 80% now.

[Iceberg]

I still can't see Gaston being anything until he nears the islands and moves away from the dry air.

Hopefully this shows, Earl has struggled through all of the dry air that's now behind it, a bit more infront, but a field of moisture should come in to it's west in it's path, shear is still low and with a good LLCC, I am favouring Monday or Tuesday for this to get going.

[summer blizzard]

http://www.ssd.noaa.gov/goes/flt/t3/rb-l.jpg

Still got the circulation however convection is still sparse on its eastern side, lowered to 70%.

[Paranoid]

Back up to 80% again.

[AderynCoch]

Continued gradual development likely in the short term, with dry air inhibiting significant strengthening. If the circulation can survive interaction with the mountains of Puerto Rico and Hispaniola, there's every chance Gaston could head straight into the Gulf of Mexico. Jeff Masters makes the point that earlier strengthening is more likely to make Gaston turn towards the northwest due to interaction with a trough moving off the eastern seaboard: http://www.wunderground.com/blog/JeffMasters/show.html.