000 WTPZ41 KNHC 142036 TCDEP1 TROPICAL STORM PRISCILLA DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP162013 200 PM PDT MON OCT 14 2013 VISIBLE SATELLITE IMAGES INDICATE THAT THE LOW-LEVEL CENTER IS NOT AS WELL DEFINED AS IT WAS YESTERDAY...AND IT REMAINS LOCATED ALONG THE EASTERN EDGE OF THE DEEP CONVECTION. A 1706 UTC ASCAT PASS SUGGESTS THAT THE AREA OF TROPICAL-STORM-FORCE WINDS MAY HAVE SHRUNK SINCE LAST NIGHT...BUT A FEW VECTORS WITHIN THE SOUTHWESTERN QUADRANT APPEAR TO BE HIGH ENOUGH TO EKE OUT AN INTENSITY OF 40 KT. MODERATE TO STRONG DEEP-LAYER EASTERLY SHEAR SHOULD CONTINUE TO AFFECT PRISCILLA FOR ANOTHER 12 HOURS OR SO...BUT THEN SHOULD DECREASE TO POSSIBLY SUPPORT SOME STRENGTHENING. HOWEVER... PRISCILLA IS ALREADY INGESTING A STABLE STRATOCUMULUS FIELD INTO ITS CIRCULATION FROM THE NORTHWEST...SO THE POOR THERMODYNAMIC ENVIRONMENT TO THE NORTH MAY BE THE STRONGEST LIMITING FACTOR FOR SIGNIFICANT INTENSIFICATION. INCREASING SOUTHWESTERLY VERTICAL SHEAR AND COLDER WATER ARE EXPECTED TO AFFECT PRISCILLA BY DAY 3...AND THE CYCLONE SHOULD THEREFORE WEAKEN TO A REMNANT LOW BY DAY 4...IF NOT SOONER. THE 12Z GFDL AND HWRF RUNS ARE SIGNIFICANTLY WEAKER THAN THE 06Z RUNS...AND NO LONGER SHOW PRISCILLA REACHING NEAR HURRICANE INTENSITY. AS A RESULT...THE NHC INTENSITY FORECAST HAS BEEN ADJUSTED SLIGHTLY DOWNWARD ON THIS CYCLE. PRISCILLA IS SLOWING DOWN AND HAS AN INITIAL MOTION OF 360/8 KT. THE MID-LEVEL RIDGE WHICH CURRENTLY STRETCHES ACROSS MEXICO IS FORECAST TO BUILD WESTWARD OVER THE NEXT COUPLE OF DAYS AS TROPICAL STORM OCTAVE DISSIPATES NEAR THE BAJA CALIFORNIA PENINSULA. THE RIDGE WILL FORCE PRISCILLA TO SLOW DOWN AND TURN NORTHWESTWARD WITHIN THE NEXT 24 HOURS. AS INDICATED IN THE PREVIOUS FORECAST... THE TRACK GUIDANCE...WITH THE EXCEPTION OF THE GFDL...HAS AGAIN SHIFTED WESTWARD. THE NHC OFFICIAL FORECAST IS ALSO SHIFTED IN THAT DIRECTION...BUT THE ADJUSTMENT IS NOT AS BIG AS WHAT WAS NEEDED EARLIER THIS MORNING. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 15.7N 115.8W 40 KT 45 MPH 12H 15/0600Z 16.6N 116.0W 45 KT 50 MPH 24H 15/1800Z 17.3N 116.9W 45 KT 50 MPH 36H 16/0600Z 18.0N 118.1W 45 KT 50 MPH 48H 16/1800Z 18.8N 119.2W 40 KT 45 MPH 72H 17/1800Z 19.8N 120.8W 30 KT 35 MPH 96H 18/1800Z 19.6N 121.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 19/1800Z 18.3N 123.2W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ FORECASTER BERG