[StBernard] TS ALBERTO Discussion 6

[Westley Annis]

000
WTNT41 KNHC 111438
TCDAT1
TROPICAL STORM ALBERTO DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL012006
1100 AM EDT SUN JUN 11 2006

THE AIR FORCE HURRICANE HUNTERS MEASURED A 1400-FT FLIGHT-LEVEL WIND OF 51
KT IN A BAND OF STRONG WINDS WELL TO THE EAST-NORTHEAST OF THE CENTER.
THERE WAS A 1200 UTC SHIP REPORT OF 33 KT IN THAT SAME AREA.  BASED ON THESE
DATA...THE SYSTEM IS BEING UPGRADED TO A TROPICAL STORM.  HAVING SAID
THAT...THE SATELLITE PRESENTATION OF THE STORM IS NOT VERY IMPRESSIVE.
ALTHOUGH THE LOW-CLOUD CENTER IS NOW FAIRLY WELL-DEFINED...STRONG
SOUTHWESTERLY SHEAR CONTINUES TO DISPLACE DEEP CONVECTION AWAY FROM THE
CENTER.  GLOBAL MODELS PREDICT THIS SHEAR TO INCREASE...SO NOT MUCH
ADDITIONAL STRENGTHENING IS ANTICIPATED.  THE OFFICIAL INTENSITY FORECAST IS
IN GOOD AGREEMENT WITH THE LATEST SHIPS AND GFDL MODEL PREDICTIONS.

THE CYCLONE HAS MOVED A LITTLE FARTHER TO THE WEST THAN EARLIER
PREDICTED...HOWEVER A MORE NORTHWARD COMPONENT OF MOTION MAY NOW BE
DEVELOPING.  INITIAL MOTION ESTIMATE IS 320/8.  A MID-LEVEL RIDGE TO THE
NORTH OF THE STORM IS CURRENTLY WEAKENING AND A TROUGH IS FORECAST TO
AMPLIFY OVER THE EASTERN UNITED STATES DURING THE NEXT COUPLE OF DAYS.
THEREFORE...IF THE TROPICAL CYCLONE IS ABLE TO MAINTAIN AT LEAST A PARTIALLY
COHERENT VERTICAL STRUCTURE...IT WOULD RESPOND TO THIS STEERING REGIME BY
TURNING TOWARD THE NORTHEAST WITH SOME INCREASE IN FORWARD SPEED DURING THE
NEXT 48 HOURS.  HOWEVER...IF ALBERTO BECOMES EVEN MORE SEVERELY SHEARED...
IT WOULD MORE LIKELY RESPOND TO SHALLOW-LEVEL ENVIRONMENTAL FLOW AND REMAIN
IN THE GULF OF MEXICO WHILE WEAKENING.  THIS LATTER SCENARIO CANNOT BE RULED
OUT.  THE OFFICIAL FORECAST IS SIMILAR TO...ALBEIT SLOWER THAN...THE TRACK
PREDICTION FROM THE PREVIOUS PACKAGE...AND IS VERY CLOSE TO THE CONSENSUS OF
THE GFS...GFDL...
GFDN...U.K. MET...AND NOGAPS MODEL TRACKS.

A TROPICAL STORM WATCH MAY BE REQUIRED FOR PORTIONS OF THE NORTHEASTERN GULF
OF MEXICO COAST LATER TODAY.
 
FORECASTER PASCH
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/1500Z 23.9N  88.1W    40 KT
 12HR VT     12/0000Z 24.9N  88.7W    45 KT
 24HR VT     12/1200Z 26.0N  87.8W    45 KT
 36HR VT     13/0000Z 27.3N  85.8W    45 KT
 48HR VT     13/1200Z 28.5N  83.5W    45 KT
 72HR VT     14/1200Z 32.0N  77.0W    40 KT...EXTRATROPICAL
 96HR VT     15/1200Z 39.0N  67.0W    40 KT...EXTRATROPICAL
120HR VT     16/1200Z 46.0N  54.0W    40 KT...EXTRATROPICAL
 
 
$$