000 WTPZ41 KNHC 140855 TCDEP1 TROPICAL STORM PAUL DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP162012 200 AM PDT SUN OCT 14 2012 THE SATELLITE APPEARANCE OF PAUL IN CONVENTIONAL IMAGERY IS A BIT MISLEADING. A CENTRAL DENSE OVERCAST WITH VERY COLD CLOUD TOP TEMPERATURES HAS FORMED IN RECENT HOURS...AND A WELL-DEFINED CURVED BAND IS PRESENT OVER THE NORTHWESTERN SEMICIRCLE OF THE CYCLONE. HOWEVER...MICROWAVE AND SCATTEROMETER DATA INDICATE THAT THERE REMAINS A CONSIDERABLE WESTWARD TILT OF THE VORTEX....WITH THE LOW- TO MID-LEVEL CIRCULATIONS SEPARATED BY 20-30 N MI. WHILE DVORAK T-NUMBERS REMAIN AT 3.0 FROM BOTH SATELLITE AGENCIES...THE 0526 UTC ASCAT PASS ONLY SUGGESTED MAXIMUM WINDS OF ABOUT 40 KT. THE INITIAL INTENSITY IS KEPT AT 45 KT IN BASIC AGREEMENT WITH THESE DATA. PAUL HAS BEEN MOVING ON A WESTERLY HEADING BUT AT A SLOWER FORWARD SPEED...AND THE LONG-TERM MOTION ESTIMATE IS 280/08. THE CYCLONE IS REACHING A REGION OF WEAK STEERING FLOW AS IT ROUNDS THE WESTERN END OF A MID-LEVEL RIDGE EXTENDING SOUTHWESTWARD FROM NORTHERN MEXICO. A MID- TO UPPER-LEVEL LOW SEEN IN WATER VAPOR IMAGERY NEAR 26N 122W SHOULD APPROACH THE CYCLONE DURING THE NEXT 24-36 HOURS... CAUSING PAUL TO TURN ABRUPTLY NORTHWARD WITH AN INCREASE IN FORWARD SPEED. AFTER 96 HOURS...PAUL SHOULD TURN NORTHWESTWARD AND THEN WESTWARD AROUND THE CLOSED LOW...ASSUMING THAT IT MAINTAINS ITS VERTICAL INTEGRITY. THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO...AND THE OVERALL SPREAD IN THE MODEL SOLUTIONS IS FAIRLY LOW. THE NHC TRACK FORECAST IS AROUND THE MIDDLE OF THE GUIDANCE ENVELOPE NEAR THE MULTI-MODEL CONSENSUS...BUT TO THE LEFT OF THE GFS AND ECMWF MODELS THROUGH 36 HOURS. THE EASTERLY SHEAR PLAGUING PAUL HAS APPARENTLY NOT SUBSIDED...EVEN THOUGH SHIPS AND UW-CIMSS SHEAR ANALYSES SUGGEST OTHERWISE. HOWEVER...LARGE-SCALE MODELS FORECAST A VERY MOIST AND UNSTABLE ENVIRONMENT WITH LIGHT SHEAR AND WARM WATERS DURING THE NEXT DAY OR TWO WHICH SHOULD SUPPORT INTENSIFICATION TO HURRICANE STRENGTH. A SHARP INCREASE OF SOUTHERLY SHEAR IS LIKELY IN 48-72 HOURS AS PAUL INTERACTS WITH THE MID- TO UPPER-LEVEL LOW NEARING IT...AND STEADY WEAKENING IS FORECAST EVEN THOUGH SSTS WILL ONLY GRADUALLY BE DECREASING. BY 96 HOURS...THE CYCLONE WILL BE OVER EVEN COOLER WATERS...AND COULD DECOUPLE ONCE THE SHEAR BECOMES PROHIBITIVELY HIGH. THE NHC INTENSITY FORECAST IS CHANGED LITTLE FROM THE PREVIOUS ONE AND IS NEAR A CONSENSUS OF THE LGEM AND INTENSITY CONSENSUS AIDS ICON AND IVCN. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 14.3N 114.5W 45 KT 50 MPH 12H 14/1800Z 15.1N 115.0W 55 KT 65 MPH 24H 15/0600Z 16.6N 115.2W 65 KT 75 MPH 36H 15/1800Z 18.5N 115.0W 70 KT 80 MPH 48H 16/0600Z 21.1N 114.5W 65 KT 75 MPH 72H 17/0600Z 25.7N 114.4W 50 KT 60 MPH 96H 18/0600Z 28.0N 116.5W 30 KT 35 MPH 120H 19/0600Z 28.6N 118.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ FORECASTER KIMBERLAIN