000
WTPZ41 KNHC 160831
TCDEP1
 
TROPICAL DEPRESSION PRISCILLA DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162013
200 AM PDT WED OCT 16 2013
 
CONVECTION CONTINUES TO PULSE NEAR AND TO THE WEST OF THE CENTER.
HOWEVER...THE OVERALL CONVECTIVE PATTERN HAS CHANGED LITTLE OVER
THE PAST 12H...SO THE INITIAL INTENSITY REMAINS UNCHANGED AT 30
KT...WHICH IS AN AVERAGE OF SATELLITE INTENSITY ESTIMATES OF 35 KT
FROM UW-CIMSS ADT...30 KT FROM TAFB...AND 25 KT FROM SAB.
 
PASSIVE MICROWAVE FIXES INDICATE THAT PRISCILLA IS STILL MOVING AT
290/06 KT. THE CYCLONE IS EXPECTED TO MOVE WEST-NORTHWESTWARD FOR
THE NEXT 24H OR SO DUE TO A DEEP-LAYER RIDGE SITUATED TO THE NORTH
AND EAST OF PRISCILLA. AS THE CYCLONE GRADUALLY WEAKENS AND BECOMES
A VERTICALLY SHALLOW REMNANT LOW...A TURN TOWARD THE WEST IS
FORECAST BY 36H...FOLLOWED BY A WEST-SOUTHWESTWARD MOTION AT 48H
AND BEYOND AS THE WEAKENED SYSTEM GETS STEERED BY THE LOW-LEVEL
NORTHEASTERLY TRADE WIND FLOW. THE NHC TRACK FORECAST IS SIMILAR TO
THE PREVIOUS ADVISORY AND THE MULTI-MODEL CONSENSUS TVCE.
 
THE SHEAR IS FORECAST TO REMAIN LOW FOR THE NEXT 12-18H WHILE
PRISCILLA REMAINS OVER MARGINALLY WARM SSTS. HOWEVER...BY 24H AND
BEYOND...THE CYCLONE WILL BE MOVING INTO A REGION OF MODERATE
SOUTHWESTERLY WIND SHEAR AND DRIER MID-LEVEL AIR...WHILE ALSO
MOVING OVER SUB-26C SSTS. THIS COMBINATION OF UNFAVORABLE
CONDITIONS SHOULD CAUSE PRISCILLA TO WEAKEN AND DEGENERATE INTO A
REMNANT LOW BY 36H AND DISSIPATE AFTER 72H...IF NOT SOONER.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/0900Z 17.9N 118.6W   30 KT  35 MPH
 12H  16/1800Z 18.3N 119.7W   30 KT  35 MPH
 24H  17/0600Z 18.6N 120.9W   25 KT  30 MPH
 36H  17/1800Z 18.7N 122.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 48H  18/0600Z 18.5N 123.1W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  19/0600Z 17.7N 125.3W   15 KT  15 MPH...POST-TROP/REMNT LOW
 96H  20/0600Z...DISSIPATED
 
$$
FORECASTER STEWART