000
WTNT42 KNHC 170842
TCDAT2
 
HURRICANE RAFAEL DISCUSSION NUMBER  19
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL172012
500 AM AST WED OCT 17 2012
 
RAFAEL IS STARTING TO TAKE ON SOME EXTRATROPICAL CHARACTERISTICS.
MOST OF THE DEEP CONVECTION IS NOW NORTH OF THE CENTER...WITH AN
INTRUSION OF DRIER AIR IN THE SOUTHERN PART OF THE CIRCULATION.
ONLY A SLIGHT WEAKENING HAS PROBABLY OCCURRED SINCE THE LAST
AIRCRAFT MISSION...SO THE INITIAL WIND SPEED IS REDUCED TO 70 KT.
WITH STRONG SHEAR AND COOL WATERS...SOME DECREASE IN STRENGTH IS
LIKELY IN THE SHORT TERM. A COLD FRONT LOCATED OVER THE WESTERN
ATLANTIC IS EXPECTED TO REACH THE CYCLONE WITHIN 12-24H AND SHOULD
COMPLETE THE EXTRATROPICAL TRANSITION OF RAFAEL. HOWEVER...GLOBAL
MODELS KEEP A POWERFUL POST-TROPICAL RAFAEL FOR SEVERAL DAYS WITH
THE AID OF BAROCLINIC FORCING...SO THE NHC FORECAST IS BASED ON
THESE MODELS AND GUIDANCE FROM THE OCEAN PREDICTION CENTER.
 
THE HURRICANE CONTINUES TO PICK UP SPEED...AND THE INITIAL MOTION
ESTIMATE IS NOW 030/29. GLOBAL MODELS ARE IN EXCELLENT AGREEMENT 
ON AN ACCELERATING NORTHEASTWARD TRACK TODAY...FOLLOWED BY A TURN
TOWARD THE EAST-NORTHEAST ON THURSDAY. THE LATEST FORECAST IS VERY
CLOSE TO THE PREVIOUS ONE WITH NO SIGNIFICANT CHANGES. IN A FEW
DAYS...POST-TROPICAL RAFAEL SHOULD MOVE IN A LARGE CYCLONIC LOOP
OVER THE NORTHEASTERN ATLANTIC AS IT WHIPS AROUND A DEVELOPING LOW
PRESSURE AREA. GUIDANCE CONTINUES TO INDICATE THAT IT WILL REMAIN
THE DOMINANT LOW PRESSURE AREA...AND THUS THE NHC FORECAST WILL
CONTINUE TO TRACK THE EXTRATROPICAL LOW CENTER THROUGHOUT THE
PERIOD.

FORECAST POSITIONS AND MAX WINDS
 
INIT  17/0900Z 35.2N  60.7W   70 KT  80 MPH
 12H  17/1800Z 38.8N  57.3W   60 KT  70 MPH
 24H  18/0600Z 43.0N  50.2W   60 KT  70 MPH...POST-TROP/EXTRATROP
 36H  18/1800Z 46.5N  40.0W   60 KT  70 MPH...POST-TROP/EXTRATROP
 48H  19/0600Z 49.0N  31.5W   55 KT  65 MPH...POST-TROP/EXTRATROP
 72H  20/0600Z 54.5N  28.5W   50 KT  60 MPH...POST-TROP/EXTRATROP
 96H  21/0600Z 50.0N  34.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
120H  22/0600Z 43.0N  29.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
 
$$
FORECASTER BLAKE