000
WTNT45 KNHC 170836
TCDAT5
TROPICAL STORM OMAR DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL152008
500 AM EDT FRI OCT 17 2008
 
THE CLOUD PATTERN HAS BECOME LESS SYMMETRIC WITH MOST OF THE
CONVECTION TO THE NORTH OF THE CENTER DUE TO WIND SHEAR. ON THE
CONTRARY... DATA FROM A 0545 UTC ASCAT PASS INDICATE THAT THE AREA
OF STRONGEST WINDS ARE LOCATED TO THE SOUTH OF THE CENTER.  BASED
ON DVORAK CLASSIFICATIONS AND DATA FROM ASCAT...THE INITIAL
INTENSITY HAS BEEN LOWERED TO 50 KNOTS. THE CYCLONE IS HEADING
TOWARD INCREASING SHEAR AND COOLER WATERS. THEREFORE...THE OFFICIAL
FORECAST CALLS FOR ADDITIONAL WEAKENING FOLLOWING THE SAME
WEAKENING RATE AS THE SHIPS MODEL.  OMAR SHOULD BE FULLY
EXTRATROPICAL IN ABOUT 3 DAYS OR LESS.

THERE HAS BEEN NO SIGNIFICANT CHANGE ON THE INITIAL MOTION AND OMAR
IS STILL HEADING TOWARD THE NORTHEAST OR 040 DEGREES AT 22 KNOTS.
OMAR SHOULD CONTINUE ON THE SAME GENERAL TRACK. HOWEVER...A
DECREASE IN FORWARD SPEED IS EXPECTED SINCE THE TROUGH THAT HAS
BEEN FORCING OMAR TO MOVE RAPIDLY TOWARD THE NORTHEAST IS WEAKENING
RESULTING IN LIGHTER STEERING CURRENTS.  BASICALLY....ALL TRACK
MODELS ARE TIGHTLY CLUSTERED THROUGH 48 HOURS.  THEREAFTER...MODEL
THE SPREAD INCREASES BUT THEY ALL BRING THE SYSTEM ON A GENERAL
EASTWARD TRACK AND SO DOES THE OFFICIAL FORECAST.        

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/0900Z 26.0N  56.4W    50 KT
 12HR VT     17/1800Z 28.7N  54.4W    45 KT
 24HR VT     18/0600Z 31.0N  52.5W    40 KT
 36HR VT     18/1800Z 33.0N  50.5W    35 KT
 48HR VT     19/0600Z 35.0N  48.0W    35 KT...BECOMING EXTRATROPICAL
 72HR VT     20/0600Z 38.5N  42.5W    35 KT...EXTRATROPICAL
 96HR VT     21/0600Z 40.0N  35.0W    35 KT...EXTRATROPICAL
120HR VT     22/0600Z 40.0N  28.5W    35 KT...EXTRATROPICAL
 
$$
FORECASTER AVILA