Hurricane Shary

[Jack Wales]

Shari is born and although her lifespan looks to be a fairly short one, there does appear to be some scope for intensification in the next day or so. Here is the lateset from the NHC...

000

WTNT45 KNHC 290835

TCDAT5

TROPICAL STORM SHARY DISCUSSION NUMBER 2

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL202010

500 AM AST FRI OCT 29 2010

ALTHOUGH THE CENTER OF SHARY IS PARTIALLY EXPOSED...A LARGE BURST OF

CONVECTION HAS FORMED ON THE WESTERN SIDE OF THE CIRCULATION. THE

SYSTEM ALSO LOOKS A LITTLE MORE TROPICAL THAN EARLIER AS ITS

DISTANCE FROM THE UPPER-LEVEL LOW IS INCREASING AND THE CLOUD

PATTERN IS LESS DISTORTED. SATELLITE INTENSITY ESTIMATES ARE 35 KT

FROM TAFB/SAB...AND THAT WILL BE THE INITIAL WIND SPEED. THE

TROPICAL CYCLONE HAS ABOUT 24 HOURS LEFT FOR ANY INTENSIFICATION IN

AN ENVIRONMENT OF MARGINAL SSTS AND MODERATE SHEAR. AFTER THAT

TIME...THE VERTICAL WIND SHEAR INCREASES DRAMATICALLY AS THE STORM

MOVES OVER COOLER WATERS. SHARY IS EXPECTED TO BECOME

EXTRATROPICAL BY 36 HOURS AND SHOULD DISSIPATE AS IT IS ABSORBED

INTO A FRONTAL BOUNDARY BY DAY 3. THE MODEL GUIDANCE GENERALLY

SHOWS SOME STRENGTHENING IN THE SHORT TERM...AND THE OFFICIAL

FORECAST IS CLOSE TO THE PREVIOUS ONE. NOTE THAT THE GFDL AND HWRF

BOTH SHOW SHARY BECOMING A HURRICANE IN A COUPLE OF DAYS...WHICH

SEEMS HIGHLY UNLIKELY GIVEN THE VERY STRONG SHEAR FORECAST AT THAT

TIME.

THE INITIAL MOTION ESTIMATE IS ABOUT 325/16...A BIT SLOWER THAN

EARLIER. SHARY IS EXPECTED TO TURN SHARPLY TOWARD THE NORTHEAST BY

EARLY SATURDAY AS RIDGING TO THE NORTH COLLAPSES AS A MID-LATITUDE

SWINGS THROUGH THE WESTERN ATLANTIC. THE GLOBAL MODELS ARE IN

RELATIVELY GOOD AGREEMENT ON THE TRACK OF THE STORM...THOUGH THE

SPEED DIFFERENCES REMAIN. THE NEW FORECAST WILL STAY ON THE SLOWER

SIDE OF THE MODEL CONSENSUS...BETWEEN THE SOLUTIONS OF THE GFS AND

ECMWF...AND IS RELATIVELY CLOSE TO THE PREVIOUS FORECAST.

[Somerset Squall]

Shary formed in the early hours of this morning as a 35kt system. Until now, the storm has not strengthened. However, over the last few hours, the satellite imagery shows tightening of the LLC and improved banding. Thus, the intensity has increased to 50kts. Shary is in a favourable environment at present, but as Jack said, the window for further strengthening is small as upper level winds are set to strengthen over Shary tomorrow. Not only will this lead to weakening as Shary turns sharply to the northeast, it will also force the storm to become extatropical as sea temps decline along track too.

[Paranoid]

Looks more like a subtropical system to me, given the relatively weak convection. Shari may have a brief shot at hurricane strength as she's at 60mph already, but i think the NHC say this is unlikely.

[Somerset Squall]

It's with a "y" by the way guys LOL

[Somerset Squall]

Shary appears to be putting on a last spurt of intensification before extratropical transition completes. Intensity in the last advisory was bumped up to 60kts. Since then, convection hs really increased and become much deeper over the LLC as the storm remains in an unstable atmosphere. I suspect the cold upper levels and the reletively warm sea temps are enhancing the instability and thus the convection at present. Latest satelitte estimates indicate an intensity of 65kts, so Shary may well be a hurricane. We shall see as the next NHC advisory comes out within the next half hour.

[Somerset Squall]

There we have it, Shary has surprisingly become a 65kt hurricane! Latest from NHC:

HURRICANE SHARY DISCUSSION NUMBER 6

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL202010

500 AM AST SAT OCT 30 2010

SHARY POSES A BIT OF A CONUNDRUM THIS MORNING. THE LATEST SATELLITE

IMAGES SHOW THAT DEEP CONVECTION HAS CONTINUED TO GROW AND BECOME

MORE SYMMETRIC NEAR THE CENTER. IN ADDITION...TRMM PASSES FROM

OVERNIGHT INDICATED THE DEVELOPMENT OF A SMALL EYE FEATURE IN THE

37-GHZ CHANNEL. WHILE DVORAK T-NUMBERS ARE HIGHER THAN EARLIER

...THEY ARE FAR FROM SUPPORTING HURRICANE INTENSITY...ALTHOUGH

THESE SATELLITE ESTIMATES ARE CLEARLY NOT HANDLING THIS SYSTEM WELL.

THE DEEPENING OF CONVECTION AND THE EYE FEATURE IN MICROWAVE IMAGERY

SUGGEST A FURTHER ORGANIZATION OF SHARY AND AT LEAST A NOMINAL

INCREASE IN WIND SPEED FROM THE 60 KT OBSERVED FROM THE AIRCRAFT.

NORMALLY A 5-KT WIND ADJUSTMENT WOULD NOT REQUIRE THIS MUCH

DISCUSSION...BUT A CHANGE IN STATUS DOES COMPLICATE MATTERS. IT IS

HARD TO DISCOUNT THE LARGE CONVECTIVE INCREASE AND THE SIGNIFICANT

IMPROVEMENT ON MICROWAVE IMAGES SINCE THE AIRCRAFT DEPARTED...THUS

THE INITIAL WINDS ARE NUDGED UPWARD TO 65 KT. THIS IS A GOOD CASE

OF A SMALL HURRICANE THAT WAS VERY UNLIKELY TO BE OBSERVED BEFORE

THE RECENT ERA WHEN MICROWAVE SATELLITE IMAGERY WAS AVAILABLE.

THE TRMM PASSES AND GEOSTATIONARY SATELLITE IMAGERY INDICATE THAT

SHARY HAS ACCELERATED CONSIDERABLY AND IS NOW SPEEDING

NORTHEASTWARD AT ABOUT 30 KT. THIS GENERAL TRACK IS EXPECTED TO

CONTINUE WHILE THE SYSTEM REMAINS ENTRENCHED IN SOUTHWESTERLY

MID-LATITUDE FLOW. A COLD FRONT RAPIDLY APPROACHING SHARY IS

EXPECTED TO CAUSE THE HURRICANE TO BECOME AN EXTRATROPICAL LOW

WITHIN 12 TO 24 HOURS BEFORE ABSORBING THE CYCLONE BY 36 HOURS. THE

GLOBAL MODELS ARE IN GOOD AGREEMENT ON THIS TRANSITION...AND THE

NEW FORECAST IS ADJUSTED TO THE RIGHT TO ACCOUNT FOR THE INITIAL

MOTION AND THE LATEST TRACK GUIDANCE. SHARY SHOULD BEGIN TO WEAKEN

SOON DUE TO INCREASING SHEAR AS IT MOVES OVER WATERS COOLER THAN

76F. THE INTENSITY FORECAST IS BASICALLY AN UPDATE OF THE PREVIOUS

ONE AFTER ACCOUNTING FOR THE SLIGHTLY HIGHER INITIAL WINDS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 30/0900Z 33.6N 59.4W 65 KT

12HR VT 30/1800Z 35.7N 54.6W 55 KT

24HR VT 31/0600Z 38.5N 48.0W 45 KT...POST-TROP/EXTRATROP

36HR VT 31/1800Z...ABSORBED BY A COLD FRONT

$$

FORECASTER BLAKE

[Somerset Squall]

Shary is doing remarkably well at the moment in 30kt+ of shear and waters at around 23C. Yes, the convection is not so symmetrical, but Shary's eye is still clear to see, and she remains a hurricane for now. I expect Shary to rapidly degenerate tomorrow however, the lopsided convection is the first signs of a decline...

[Somerset Squall]

Shary quickly lost it's convection after I posted, and NHC have declared her extratropical. Interesting little system, especially for becoming a hurricane where it did when we are so near November!

[Cookie]

totally missed the boat with this one didn't I :lol:

[Somerset Squall]

LOL Cookie