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Tropical Storm ROSA (Text)

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TROPICAL STORM ROSA DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP172012
200 AM PDT SAT NOV 03 2012
 
CONVENTIONAL SATELLITE IMAGERY SHOWS ROSA MAINTAINING A SHEARED
SCENE TYPE THIS MORNING...WITH A SMALL AREA OF -80C OVERSHOOTING
COLD CLOUD TOPS NEAR THE PARTLY EXPOSED CENTER OF CIRCULATION.
ALTHOUGH THE DVORAK SATELLITE INTENSITY ESTIMATES ARE 2.5/35 KT
FROM BOTH TAFB AND SAB...THE INITIAL INTENSITY WILL REMAIN THE SAME
AS THE PREVIOUS ADVISORY...40 KT...DUE TO LITTLE OR NO CHANGE IN
THE CLOUD PATTERN FROM 6 HOURS AGO. UW-CIMSS SHEAR PRODUCT AND
WATER VAPOR IMAGERY SHOW ROSA MOVING IN AN UNFORGIVING ENVIRONMENT
CONSISTING OF 30-40 KT OF SOUTHWESTERLY SHEAR AND AN INTRUDING
DRY/STABLE MARINE-LAYER AIR MASS. THESE TWO INHIBITING
CONTRIBUTIONS SHOULD QUICKLY WEAKEN ROSA INTO A DEPRESSION WITHIN
THE NEXT 12 HOURS...AND ULTIMATELY TO A POST-TROPICAL REMNANT LOW
IN 24 HOURS. THE OFFICIAL INTENSITY FORECAST ALSO REFLECTS
DISSIPATION BY DAY 4 WHICH IS CONSISTENT WITH A CONSENSUS OF THE
GLOBAL MODELS.
 
THE INITIAL MOTION ESTIMATE IS A PERSISTENT 260/4...OR TOWARD THE
WEST. A LOW- TO MID-TROPOSPHERIC NARROW RIDGE TO THE NORTH IS
STEERING THE CYCLONE ON ITS CURRENT HEADING. A MAJORITY OF
THE DYNAMICAL MODELS CONTINUE TO INDICATE THAT ROSA WILL TURN
TOWARD THE NORTHWEST AROUND THE 24 HOUR PERIOD IN RESPONSE TO AN
AMPLIFYING DEEP-LAYER TROUGH TO THE NORTHWEST OF THE TROPICAL
STORM.  THE GUIDANCE SPREAD...UNFORTUNATELY...REMAINS QUITE LARGE.
THE UKMET IS SHOWING A FLATTER TRACK...A GENERAL WEST TO
WEST-NORTHWEST DIRECTION WITH TIME...WHILE THE GFS IS TO THE FAR
RIGHT OF THE MODEL CLUSTER AND INDICATES A SHARP TURN TOWARD THE
NORTH IN 12 HOURS. THE NHC TRACK FORECAST RESEMBLES THE PREVIOUS
ADVISORY AND IS BASED ON THE MULTI-MODEL CONSENSUS WHICH IS
ESSENTIALLY BETWEEN THE TWO AFOREMENTIONED OUTLIERS.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  03/0900Z 12.6N 119.7W   40 KT  45 MPH
 12H  03/1800Z 12.7N 120.1W   30 KT  35 MPH
 24H  04/0600Z 12.8N 120.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  04/1800Z 13.1N 120.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  05/0600Z 13.5N 121.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  06/0600Z 14.3N 122.3W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  07/0600Z...DISSIPATED
 
$$
FORECASTER ROBERTS
 
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