000
WTPZ44 KNHC 290854
TCDEP4
 
TROPICAL STORM HILARY DISCUSSION NUMBER  33
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092011
200 AM PDT THU SEP 29 2011
 
COLDER WATER AND INCREASING SHEAR ARE TAKING A TOLL ON HILARY. THE
COVERAGE OF DEEP CONVECTION HAS BEEN SHRINKING AND CLOUD TOP
TEMPERATURES ARE WARMING. IN ADDITION...MICROWAVE IMAGES INDICATE
THAT THE LOW-LEVEL CENTER OF HILARY HAS BECOME DETACHED FROM THE
HIGHER-LEVEL CIRCULATION. IN ACCORDANCE WITH A BLEND OF T- AND CI-
NUMBERS FROM TAFB AND SAB AND THE LATEST UW-CIMSS ADT VALUES...THE
INITIAL INTENSITY IS REDUCED TO 50 KT. THE RATE OF DECAY IS LIKELY
TO ACCELERATE FURTHER NOW THAT A DECOUPLING OF THE CIRCULATION HAS
OCCURRED...NOT TO MENTION THE EVEN HIGHER SHEAR FORECAST AND COLDER
WATERS ALONG THE TRACK. THE CIRCULATION IS EXPECTED TO QUICKLY SPIN
DOWN...AND REMNANT LOW STATUS IS LIKELY IN ABOUT 24 HOURS. THE
NEW OFFICIAL FORECAST IS NEARLY IDENTICAL TO THE PREVIOUS ONE AND IN
LINE WITH THE STATISTICAL/ DYNAMICAL GUIDANCE.
 
THE CENTER OF HILARY IS NEARLY IMPOSSIBLE TO LOCATE USING
GEOSTATIONARY SATELLITE IMAGERY. LUCKILY...A COUPLE OF EARLIER
MICROWAVE OVERPASSES SUGGESTED THAT THE TROPICAL CYCLONE IS
MAINTAINING A NORTHWESTWARD HEADING...325 DEGREES...AT 6 KNOTS. SO
LONG AS THE CIRCULATION OF HILARY MAINTAINS SOME VERTICAL
INTEGRITY...THE TRACK SHOULD DUMBBELL CYCLONICALLY AROUND A MID- TO
UPPER-LEVEL LOW APPROACHING THE STORM FROM THE WEST. AFTER THE
DECOUPLING OF THE CIRCULATION IS COMPLETE...THE SHALLOW CIRCULATION
AND ULTIMATELY ITS REMNANT SHOULD TURN WESTWARD AND THEN
SOUTHWESTWARD IN THE LOW-LEVEL FLOW ASSOCIATED WITH THE EASTERN
PACIFIC SUBTROPICAL HIGH. AS HAS BEEN THE CASE IN PREVIOUS
FORECASTS...THE LATEST TRACK PREDICTION HAS BEEN SHIFTED A LITTLE
TO THE LEFT FOLLOWING THE MULTI-MODEL CONSENSUS...BUT IS NOT
MATERIALLY DIFFERENT FROM THE PREVIOUS ONE. 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  29/0900Z 20.0N 119.9W   50 KT  60 MPH
 12H  29/1800Z 20.8N 120.4W   40 KT  45 MPH
 24H  30/0600Z 22.0N 121.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  30/1800Z 23.0N 121.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  01/0600Z 23.5N 122.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  02/0600Z 23.5N 124.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  03/0600Z 22.5N 125.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  04/0600Z...DISSIPATED
 
$$
FORECASTER KIMBERLAIN