Tropical storm Gabrielle

[kold weather]

Well overnight recon found winds high enough to justify Invest 99L to be upgraded. The latest IR images shows that the convection is now very lop-sided wit hthe convection slightly displaced to the east of the center, that is by the way a textbook sign of the system being subtropical and probably comes back to the systems cold core origin and the interaction with the shear over those numerous hours.

System is heading steadily a little north of WNW and looks like its going to come pretty close to the Carolinas, probably NC being at most risk. However given the dry air that is still present and also the shear this system will be limited in terms of strength, its eventual strength more down to whether it can sort out its mess of an inner circulation.

[Iceberg]

Agree it is tropical but barely and wouldn't take much go back. The sinds are almost completely not from tropical charecterisitcs.

On Sat the system looks pretty poor,phase evolution shows a warm core moving away from tropical straight after landfall.

Lanfall seems to be SC, NC, re intensity I really can't see this getting much higher as you say KW it's inner core is a mess and I can't see any strengthening coming from here, equally there won't be any more baroclinic or external strengthening until after landfall.

08/0645 UTC 30.6N 73.2W T2.5/2.5 GABRIELLE

07/2345 UTC 30.0N 71.6W ST1.5/1.5 99L

07/1745 UTC 29.6N 70.8W T2.0/2.0 99L

[Cookie]

suprised I have allready reacived a tropical storm alart for this.

Tropical Storm GABRIELLE is forecast to strike land to the following likelihood(s) at the given lead time(s):

Green Alert Country(s) or Province(s)

the United States

probability for TS is 50% in about 33 hours

[Paranoid]

If it remains subtropical then i don't see it reaching winds of any more than 60mph. I think there's only ever been one SS with Hurricane force winds.

[kold weather]

Well subtropical storm Gabrille has just had its convection blown off by it seems a fresh batch of shear from. it still has obviously a strong LLC present with it however unless it can regain its convection then it won't strengthen and instead weaken. Probably some rain and wind but nothing really out of the norm of a low pressure system that rolls off the coast increasingly at this time of year.

Note track is probably going to take it to the east of the NC as the LLC has been moving quite northerly recently, indeed the LLC took a pretty noteable northerly jog over the last few hours. All the deeper convection is on the northern side of the LLC being sheared.

[Somerset Squall]

Gabrielle has now being classed as tropical as convection forms over it's center. Brief strengthening could occur as shear might relax for a time tonight before pepping up again tommorrow, which should halt further intensification before it turns extratropical by 96hrs. It is forecasted to be absorbed by another extratropical low by 120hrs.

TROPICAL STORM GABRIELLE DISCUSSION NUMBER 4

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072007

500 PM EDT SAT SEP 08 2007

AFTER BEING BRIEFLY INVOLVED WITH THE CIRCULATION CENTER THIS

MORNING...THE CONVECTION HAS SPENT MOST OF THE DAY QUITE SEPARATED

FROM THE CENTER...AND THE BAND IN THE NORTHEASTERN QUADRANT HAS

DISSIPATED. RECENTLY...HOWEVER...THE CIRCULATION CENTER AND THE

REMAINING CONVECTION IN THE NORTHWESTERN QUADRANT ARE IN THE

PROCESS OF BEING REUNITED. GABRIELLE HAS TAKEN ON MORE OF

THE APPEARANCE OF A SHEARED TROPICAL CYCLONE...AND BOTH AMSU AND

AIRCRAFT DATA SUGGEST THERE IS A WEAK WARM CORE...SO GABRIELLE IS

BEING DESIGNATED AS A TROPICAL STORM ON THIS ADVISORY. MAXIMUM

WINDS FROM THE AIR FORCE PLANE AT THE FLIGHT-LEVEL OF ABOUT 1000 FT

WERE ONLY 39 KT...EVEN WITHIN THE CONVECTION IN THE NORTHWESTERN

QUADRANT. GIVEN THOSE DATA AND THE OVERALL LESSENING OF THE

CONVECTIVE DEPTH AND COVERAGE...THE INTENSITY IS LOWERED TO 35 KT.

THE CURRENT SOUTHEASTERLY SHEAR MIGHT STILL LESSEN TEMPORARILY

TONIGHT...BUT WILL INCREASE FROM THE NORTH TOMORROW. THAT WINDOW

OF OPPORTUNITY FOR STRENGTHENING IS THE BASIS FOR THE OFFICIAL

FORECAST TO STILL CALL FOR SLIGHT STRENGTHENING. THE NEW FORECAST

IS LOWERED COMPARED TO THE PREVIOUS ADVISORY...CALLING FOR

GABRIELLE TO REACH ONLY 45 KT NEAR THE COAST OF NORTH

CAROLINA...AND THIS IS CONSISTENT WITH MOST OF THE GUIDANCE.

LITTLE CHANGE IN STRENGTH IS FORECAST ONCE GABRIELLE TURNS

NORTHEASTWARD AND EVENTUALLY BECOMES EXTRATROPICAL.

THE EXPOSED CIRCULATION CENTER IS EASY TO FIND...BUT THE SMALLER

SWIRL THAT APPEARS TO BE THE CENTER ON SATELLITE IMAGERY SEEMS TO

HAVE ROTATED ABOUT A LARGER MEAN CENTER DURING THE DAY. THE MOTION

OF THE MEAN CENTER IS NORTHWESTWARD AND SLOWER THAN BEFORE...OR

ROUGHLY 320/7. THE OFFICIAL TRACK FORECAST AND SUPPORTING

REASONING HAVE NOT NOTICEABLY CHANGED...WITH GABRIELLE EXPECTED TO

ROTATE AROUND THE WESTERN ATLANTIC RIDGE AND INTO THE MIDLATITUDE

WESTERLIES DURING THE NEXT COUPLE OF DAYS...PASSING NEAR OR OVER THE

OUTER BANKS OF NORTH CAROLINA ALONG THE WAY IN 24-36 HOURS. THE

NEW FORECAST ALSO CALLS FOR GABRIELLE TO BE ABSORBED BY A LARGER

SYSTEM OVER THE NORTH ATLANTIC BY 120 HOURS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 08/2100Z 32.4N 74.7W 35 KT

12HR VT 09/0600Z 33.2N 75.4W 40 KT

24HR VT 09/1800Z 34.6N 75.8W 45 KT

36HR VT 10/0600Z 36.0N 74.8W 45 KT

48HR VT 10/1800Z 37.6N 72.8W 45 KT

72HR VT 11/1800Z 41.5N 65.5W 45 KT...BECOMING EXTRATROPICAL

96HR VT 12/1800Z 46.0N 55.0W 45 KT...EXTRATROPICAL

120HR VT 13/1800Z...ABSORBED BY LARGER EXTRATROPICAL SYSTEM

$$

FORECASTER KNABB

Edited September 8, 2007 by Somerset Squall

[Cookie]

I have just read that winds speeds have dropped to 40 mph!!

great satellite animation loop of Tropical Storm Gabrielle, click below!

http://www.stormvideographer.com/weathervi...rielle_loop.gif

taken from the above site!

http://www.stormvideographer.com/blog/

[Cookie]

NEW ALERT!

Tropical Storm GABRIELLE is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

the United States

probability for TS is 60% in about 21 hours

Yellow Alert City(s) and Town(s)

Hatteras (35.2 N, 75.6 W)

probability for TS is 60% in about 21 hours

Kitty Hawk (36.1 N, 75.7 W)

now up to a yellow alert

[Cookie]

Tropical Storm GABRIELLE is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

the United States

probability for TS is 80% within 9 hours

Yellow Alert City(s) and Town(s)

Hatteras (35.2 N, 75.6 W)

probability for TS is 80% within 9 hours

Kitty Hawk (36.1 N, 75.7 W)

probability for TS is 60% in about 21 hours

Capeville (37.2 N, 75.9 W)

probability for TS is 55% in about 21 hours

Norfolk (36.9 N, 76.2 W)

probability for TS is 55% in about 21 hours

[mettalfabrik]

THE CENTER OF TROPICAL STORM GABRIELLE AT 09/1200 UTC WAS NEAR

34.2N 76.4W OR ABOUT 26 NM SSE OF CAPE LOOKOUT NORTH CAROLINA.

GABRIELLE IS NOW MOVING N-NW NEAR 9 KT. THE ESTIMATED MINIMUM

CENTRAL PRESSURE AS MEASURED BY AN AIR FORCE RESERVE UNIT

RECONNAISSANCE AIRCRAFT IS 1005 MB. THE MAXIMUM SUSTAINED WIND

SPEEDS ARE 45 KT WITH GUSTS TO 55 KT. PLEASE REFER TO THE NHC

FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC

AND THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE

DETAILS...INCLUDING THE LATEST WATCH AND WARNING INFORMATION.

GABRIELLE IS EXPECTED TO TURN TO THE NORTH LATER TODAY AND THEN

TO THE NORTHEAST TONIGHT. ON THIS TRACK...THE CENTER OF

GABRIELLE WOULD BE MOVING ACROSS THE OUTER BANKS THIS AFTERNOON.

SOME STRENGTHENING IS EXPECTED PRIOR TO LANDFALL. NUMEROUS

MODERATE CONVECTION IS WITHIN 60NM OF 33.5N76W. SCATTERED

MODERATE...IN SPIRAL RAIN BANDS...IS ELSEWHERE FROM 32N-36N

BETWEEN 74W-78W. THESE BANDS CONTINUE TO AFFECT THE OUTER BANKS

OF NORTH CAROLINA AND WILL CONTINUE TO DO SO OVER THE NEXT

SEVERAL HOURS. GABRIELLE IS EXPECTED TO PRODUCE TOTAL RAINFALL

ACCUMULATIONS OF 1 TO 3 INCHES ACROSS COASTAL SECTIONS OF NORTH

CAROLINA AND SOUTHEASTERN VIRGINIA...WITH ISOLATED MAXIMUM

AMOUNTS OF 5 INCHES. ISOLATED TORNADOES ARE POSSIBLE OVER THE

OUTER BANKS TODAY.

[kold weather]

Quick update on Gabby, looks better then ever right now though it looks like some northerly shear has recently picked up again sending most of the convection onto the southern side of the LLC. Convection is pretty strong on that southern side and recon found flight level winds of roughly 60kts wihhc does justify this system being upped to a strong tropical storm though the main winds wil lbe in the deep convection that will probably only hit the far eastern side of North Carolinas.

This system could get upto 55-60kts if shear eases off a little as it heads NE and starts to interact with the jet stream, breif strengthening via Baroclinic processes may give the system that little bit more power that it needs to pump up. not a powerful system but the 3rd landfalling tropical storm hitting the USA of the 07 season.

Edited September 9, 2007 by kold weather

[Cookie]

Tropical Storm GABRIELLE is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

the United States

probability for TS is 85% currently

Yellow Alert City(s) and Town(s)

Hatteras (35.2 N, 75.6 W)

probability for TS is 85% currently

Kitty Hawk (36.1 N, 75.7 W)

probability for TS is 65% currently

[Somerset Squall]

I didn't realise how small Gabby actually is:

http://cimss.ssec.wisc.edu/tropic/real-tim...s/winds-ir.html