000
WTNT41 KNHC 210238
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   6
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
1100 PM EDT SUN MAY 20 2012
 
ALBERTO HAS BEEN STRUGGLING TO PRODUCE DEEP CONVECTION THIS
EVENING...ALTHOUGH THERE ARE STILL BANDING FEATURES PRESENT ON THE
JACKSONVILLE DOPPLER RADAR. SATELLITE CLASSIFICATIONS AND DOPPLER
WIND DATA SUGGEST THE STORM HAS WEAKENED...AND THE INITIAL WIND
SPEED IS REDUCED TO 35 KT FOR THIS ADVISORY. LITTLE CHANGE IN
INTENSITY IS FORECAST BY MUCH OF THE GUIDANCE DUE TO ALBERTO MOVING
OVER WARM WATERS ALONG THE GULF STREAM...BUT IN A MODERATE-TO-
STRONG VERTICAL SHEAR ENVIRONMENT. THE NHC FORECAST SHOWS NO CHANGE
IN INTENSITY FOR THE NEXT COUPLE OF DAYS AND THEN WEAKENING AS THE
CYCLONE MOVES OVER MUCH COOLER WATERS. A PLAUSIBLE ALTERNATE
SCENARIO IS THAT THE STORM LOSES ALL DEEP CONVECTION DUE TO
MARGINAL THERMODYNAMIC CONDITIONS...AND BECOMES A REMNANT LOW IN A
DAY OR TWO.
 
ALBERTO HAS TURNED SOUTHWARD AND IS MOVING 180/4.  THE SYSTEM IS
EMBEDDED IN A PECULIAR PLACE WITHIN THE SOUTH SIDE OF A MID- TO
UPPER-LEVEL LOW.  THIS LOW IS EXPECTED TO WEAKEN AND MOVE
NORTHEASTWARD AS ANOTHER TROUGH MOVES INTO THE SOUTHEASTERN UNITED
STATES.  THE MODEL GUIDANCE IS IN VERY GOOD AGREEMENT ON ALBERTO
MOVING SOUTHEASTWARD AND EASTWARD DURING THE NEXT 12 HOURS OR
SO...THEN TURNING TO THE NORTHEAST WITH INCREASING FORWARD SPEED. 
THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ONE BUT HAS BEEN
ADJUSTED A BIT TO THE SOUTHEAST TO ACCOUNT FOR THE LATEST MODEL
TRENDS.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/0300Z 30.5N  80.1W   35 KT  40 MPH
 12H  21/1200Z 30.6N  79.4W   35 KT  40 MPH
 24H  22/0000Z 31.5N  77.8W   35 KT  40 MPH
 36H  22/1200Z 33.2N  75.3W   35 KT  40 MPH
 48H  23/0000Z 35.5N  72.2W   35 KT  40 MPH
 72H  24/0000Z 39.0N  66.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
 96H  25/0000Z...DISSIPATED
 
$$
FORECASTER BLAKE