000
WTPZ42 KNHC 020233
TCDEP2
 
TROPICAL STORM ROSA DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP172012
800 PM PDT THU NOV 01 2012
 
THERE HAS BEEN LITTLE CHANGE WITH ROSA OVER THE PAST FEW HOURS.
MICROWAVE AND LAST-LIGHT VISIBLE IMAGES SHOWED THAT THE LOW-LEVEL
CENTER IS STILL LOCATED ON THE WESTERN SIDE OF THE CONVECTION DUE
TO MODERATE WESTERLY SHEAR. THE INITIAL INTENSITY REMAINS 45 KT
BASED ON THE LATEST DVORAK ESTIMATES FROM TAFB AND SAB. THERE IS NO
CHANGE TO THE NHC INTENSITY FORECAST...AS ROSA SHOULD GRADUALLY
WEAKEN THROUGH THE PERIOD WHILE THE SHEAR INCREASES DUE TO AN
UPPER-LEVEL TROUGH. THE CYCLONE SHOULD BECOME A REMNANT LOW IN
ABOUT 3 DAYS.

THE CURRENT MOTION APPEARS TO BE STATIONARY...AND LITTLE NET MOTION
IS EXPECTED DURING THE NEXT 48 HOURS AS ROSA IS SITUATED EAST OF A
WEAKENING MID-LEVEL RIDGE AND SOUTH OF A FLAT MID-LEVEL TROUGH.
AFTER THAT TIME...THE MODEL GUIDANCE IS IN GENERAL AGREEMENT ON A
NORTHWESTWARD MOTION DEVELOPING AS A MID-LEVEL LOW FORMS WEST OF
BAJA CALIFORNIA AND RETROGRADES TO THE NORTH OF ROSA. WHILE THERE IS
STILL SOME LATERAL SPREAD IN THE GUIDANCE ENVELOPE...THE SPREAD HAS
DECREASED A BIT OVER THE PAST FEW CYCLES. SINCE THE PREVIOUS
OFFICIAL FORECAST LIES NEAR THE MIDDLE OF THE GUIDANCE ENVELOPE...
LITTLE CHANGE WAS MADE TO THE NHC TRACK. THE NHC FORECAST IS CLOSE
TO THE GEFS ENSEMBLE MEAN AND A BLEND OF THE ECMWF AND GFS MODELS
AT DAYS 3 THROUGH 5. 

FORECAST POSITIONS AND MAX WINDS
 
INIT  02/0300Z 13.7N 118.4W   45 KT  50 MPH
 12H  02/1200Z 13.6N 118.5W   40 KT  45 MPH
 24H  03/0000Z 13.5N 118.6W   40 KT  45 MPH
 36H  03/1200Z 13.5N 118.7W   40 KT  45 MPH
 48H  04/0000Z 13.7N 118.8W   35 KT  40 MPH
 72H  05/0000Z 14.9N 119.2W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  06/0000Z 16.7N 120.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  07/0000Z 19.0N 122.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BRENNAN