000
WTNT42 KNHC 142042
TCDAT2
 
TROPICAL STORM RAFAEL DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL172012
500 PM AST SUN OCT 14 2012
 
AFTER IMPROVING DURING THE MORNING...THE OVERALL ORGANIZATION
OF RAFAEL HAS CHANGED VERY LITTLE THIS AFTERNOON.  SHORTLY AFTER 
THE RELEASE OF THE 1500 UTC ADVISORY...THE AIR FORCE RESERVE
RECONNAISSANCE AIRCRAFT MEASURED PEAK 925 MB FLIGHT-LEVEL WINDS
OF 64 KT AND SFMR SURFACE WINDS OF 45 TO 50 KT.  BASED ON THESE 
DATA AND 1800 UTC DVORAK INTENSITY ESTIMATES OF 45 AND 55 KT FROM
TAFB AND SAB RESPECTIVELY...THE INITIAL WIND SPEED IS KEPT AT 50
KT.  RAFAEL IS EXPECTED TO REMAIN IN AN ENVIRONMENT OF MODERATE
SOUTHWESTERLY SHEAR DURING THE NEXT DAY OR TWO.  AFTER THAT TIME...
THE SHEAR IS FORECAST TO INCREASE AS A MID-LATITUDE TROUGH
APPROACHES THE CYCLONE FROM THE WEST.  MOST OF THE INTENSITY
GUIDANCE STILL CALLS FROM RAFAEL TO BECOME A HURRICANE DURING THE
NEXT DAY OR SO.  GIVEN THE LACK OF A TIGHT INNER CORE AND THE
MARGINAL UPPER-AIR PATTERN...HOWEVER...THERE IS LESS CONFIDENCE THAT
RAFAEL WILL STRENGTHEN SIGNIFICANTLY.  THE NHC INTENSITY FORECAST
HAS BEEN LOWERED SLIGHTLY FROM THE PREVIOUS ADVISORY...AND IS
CLOSEST TO THE INTENSITY CONSENSUS AND TO THE FLORIDA STATE
SUPERENSEMBLE.
 
RAFAEL IS MOVING NORTH-NORTHWESTWARD OR 330/9 KT. THERE HAS BEEN NO
CHANGE TO THE PREVIOUS TRACK FORECAST REASONING.  RAFAEL SHOULD
MOVE AROUND THE WESTERN PERIPHERY OF A DEEP-LAYER RIDGE OVER THE
CENTRAL ATLANTIC DURING THE NEXT 24 TO 36 HOURS.  BY TUESDAY...A
STRONG MID-LATITUDE TROUGH AND ASSOCIATED COLD FRONT ARE FORECAST
TO MOVE OFF THE U.S. EAST COAST.  THIS SHOULD CAUSE RAFAEL TO
ACCELERATE NORTHEASTWARD IN THE DEEP-LAYER SOUTHWESTERLY FLOW AHEAD
OF THE FRONT/TROUGH.  THE TRACK GUIDANCE REMAINS IN AGREEMENT ON
THIS OVERALL SCENARIO...ALTHOUGH THERE ARE STILL SOME SIGNIFICANT
DIFFERENCES IN HOW FAST RAFAEL WILL GAIN LATITUDE DURING THE NEXT 
COUPLE OF DAYS.  THE 1200 UTC GFS HAS TRENDED TOWARD THE SLOWER
ECMWF SOLUTION AND THE NHC FORECAST HAS BEEN ADJUSTED IN THAT
DIRECTION.  THE MODELS HAVE COME INTO BETTER AGREEMENT ON THE TRACK
AFTER EXTRATROPICAL TRANSITION...AND THE OFFICIAL FORECAST HAS BEEN
SHIFTED EASTWARD LATE IN THE PERIOD.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/2100Z 20.7N  64.7W   50 KT  60 MPH
 12H  15/0600Z 21.8N  65.6W   55 KT  65 MPH
 24H  15/1800Z 23.5N  66.2W   60 KT  70 MPH
 36H  16/0600Z 26.0N  65.8W   65 KT  75 MPH
 48H  16/1800Z 29.3N  64.3W   65 KT  75 MPH
 72H  17/1800Z 39.5N  56.5W   65 KT  75 MPH
 96H  18/1800Z 48.5N  42.0W   60 KT  70 MPH...POST-TROP/EXTRATROP
120H  19/1800Z 49.0N  30.0W   55 KT  65 MPH...POST-TROP/EXTRATROP
 
$$
FORECASTER BROWN