Sunday, November 27, 2011

"05A" - to move N-W, intensify and die over Sea !

Position :: 8.2 N and 76 E
Pressure :: 996mb

JTWC warning
-----------------------------

271500Z POSITION NEAR 12.6N 71.0E.
TROPICAL CYCLONE 05A, LOCATED APPROXIMATELY 410 NM NORTHWEST OF 
MUMBAI, INDIA, HAS TRACKED NORTHWESTWARD AT 15 KNOTS OVER THE PAST 
SIX HOURS.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THAT ALTHOUGH THE 
SYSTEM IS STILL BEING SHEARED BY SOUTHEASTERLIES ALOFT, CONVECTION 
OVER THE NORTHERN SEMICIRCLE IS PERSISTENT AND DEEPENING. THE 
CURRENT INTENSITY IS BASED ON RECENT SCATTEROMETRY DATA. UPPER LEVEL 
STREAMLINE ANALYSIS DEPICTS TC 05A UNDER AN AREA OF DIFFLUENT 
SOUTHEASTERLIES SOUTH OF THE SUBTROPICAL RIDGE AXIS. ANIMATED WATER 
VAPOR IMAGERY REVEALS THE EFFECTS OF SHEAR ON THE EASTERN SIDE OF 
THE SYSTEM BUT ALSO SHOWS EXCELLENT OUTFLOW OVER THE WESTERN 
SEMICIRCLE. A LOW- TO MID-LEVEL ANTICYCLONE SITUATED UNDER THE 
SUBTROPICAL RIDGE IS THE DOMINANT STEERING MECHANISM FOR THE STORM. 
THE ANTICYCLONE IS CURRENTLY OVER THE EAST-CENTRAL COAST OF INDIA 
AND WILL RETROGRADE TO JUST NORTH OF MUMBAI, INDIA DURING THE NEXT 
72 HOURS. TC 05A WILL STEER ALONG THE SOUTHWESTERN PERIPHERY OF THE 
ANTICYCLONE AND VERTICAL WIND SHEAR WILL EASE AS THE LOW LEVEL 
CIRCULATION CENTER MOVES CLOSER TO THE RIDGE AXIS. THE REDUCED SHEAR 
WILL ALLOW THE SYSTEM TO REACH PEAK INTENSITY NEAR TAU 48. BEYOND 19 
DEGREES NORTH LATITUDE, VERTICAL WIND SHEAR WILL INCREASE 
DRAMATICALLY AND THE SYSTEM WILL WEAKEN RAPIDLY. THERE IS 
CONSIDERABLE DISAGREEMENT IN MODEL SOLUTIONS IN THE EXTENDED RANGE. 
NOGAPS AND GFS INDICATE THE STORM WILL MAINTAIN ENOUGH STRENGTH TO 
CREST THE RIDGE AND MOVE INTO PAKISTAN AS A LOW-GRADE TROPICAL 
CYCLONE, BUT GFDN, ECMWF, AND EGRR TURN THE SYSTEM BACK TO THE 
SOUTHEAST AND RAPIDLY WEAKEN AND DISSIPATE THE SYSTEM OVER THE NORTH 
ARABIAN SEA. LONG RANGE PROGS DO NOT INDICATE A STRONG ENOUGH RIDGE 
OF HIGH PRESSURE TO FORCE THE SYSTEM TO THE SOUTHEAST, SO THE LONG 
RANGE FORECAST STAYS CLOSER TO CONSENSUS. HOWEVER, THE HIGH VERTICAL 
WIND SHEAR OVER THE NORTHERN THIRD OF THE NORTH ARABIAN SEA WILL 
MAKE IT VERY UNLIKELY THAT THE SYSTEM WILL HOLD TOGETHER LONG ENOUGH 
TO MAKE LANDFALL AS A SIGNIFICANT TROPICAL CYCLONE. THEREFORE THE 
FORECAST STAYS CLOSE TO CONSENSUS BUT DISSIPATES THE SYSTEM OVER 
WATER NEAR 20 DEGREES NORTH LATITUDE. MAXIMUM SIGNIFICANT WAVE 
HEIGHT AT 271200Z IS 16 FEET.

Latest Satellite IR shot of "05A"
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JTWC projected path
---------------------------------

IMD & COLA GFS prediction
--------------------------------------------
IMD GFS predicts that "05A" will fizzle out over N-Central Arabian sea on 1-Dec-2011.


But COLA GFS predicts that the system make weaken and crash over Pakistan, Gujarat coast on 1-Dec-2011.
Meanwhile N-E monsoon will be active along entire Tamilnadu coast till Tuesday, 29-Nov-2011

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