000 WTPZ43 KNHC 271433 TCDEP3 TROPICAL STORM MIRIAM DISCUSSION NUMBER 23 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132012 800 AM PDT THU SEP 27 2012 ENHANCED AND SHORTWAVE INFRARED IMAGERY INDICATE THAT MIRIAM IS WEAKENING RAPIDLY...AND ALL THAT REMAINS OF THE ASSOCIATED DEEP CONVECTION IS A SMALL PATCH LOCATED ABOUT 110 MILES TO THE NORTH OF THE CENTER. BASED ON A COMPROMISE OF THE DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB...THE INITIAL INTENSITY IS LOWERED TO 35 KT... WHICH COULD BE GENEROUS. SHARPLY DECREASING SEA SURFACE TEMPERATURES AND A RATHER HOSTILE WIND SHEAR ENVIRONMENT SHOULD WEAKEN THE CYCLONE TO A DEPRESSION LATER TODAY. MIRIAM IS THEN EXPECTED TO BECOME A POST-TROPICAL REMNANT LOW TONIGHT...WITH DISSIPATION OCCURRING IN 3 DAYS OR LESS...AS INDICATED BY THE SHIPS MODEL AND THE LGEM. THE INITIAL MOTION ESTIMATE IS 315/5. DURING THE NEXT 24 HOURS... MIRIAM IS EXPECTED TO SLOW DOWN AND TURN WESTWARD IN THE LOW-LEVEL STEERING FLOW PRODUCED BY THE EASTERN PACIFIC SUBTROPICAL RIDGE TO THE NORTH. AFTERWARD...THE CYCLONE IS FORECAST TO DRIFT A LITTLE LEFT OF DUE WEST IN THE WEAK EAST-NORTHEASTERLY MARINE-LAYER STEERING CURRENT BEFORE DISSIPATING IN 96 HOURS...OR LESS. THE NHC FORECAST IS AN UPDATE OF THE PREVIOUS ADVISORY AND CLOSELY FOLLOWS THE TVCE MODEL CONSENSUS AND THE FLORIDA STATE SUPERENSEMBLE. FORECAST POSITIONS AND MAX WINDS INIT 27/1500Z 22.2N 116.3W 35 KT 40 MPH 12H 28/0000Z 22.5N 116.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 24H 28/1200Z 22.5N 116.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 29/0000Z 22.4N 117.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 29/1200Z 22.3N 117.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 30/1200Z 22.0N 117.9W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 01/1200Z...DISSIPATED $$ FORECASTER ROBERTS