000 WTNT44 KNHC 131438 TCDAT4 TROPICAL STORM MARIA DISCUSSION NUMBER 28 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011 1100 AM AST TUE SEP 13 2011 THE STRUCTURE OF MARIA HAS NOT CHANGED MUCH THIS MORNING. THE LOW-LEVEL CENTER IS STILL EXPOSED TO THE WEST-NORTHWEST OF THE DEEP CONVECTION DUE TO ABOUT 20 KT OF SHEAR AS SHOWN IN THE SHIPS MODEL AND UW-CIMSS SATELLITE ANALYSES. THE INITIAL INTENSITY IS HELD AT 45 KT IN AGREEMENT WITH THE 12Z DVORAK ESTIMATES FROM TAFB AND SAB. THE UPPER-LEVEL LOW NORTH OF MARIA CAUSING THE SHEAR IS FORECAST TO WEAKEN AND LIFT NORTHWARD WITHIN 24 HOURS. HOWEVER...THE UPPER- LEVEL WINDS NEVER BECOME IDEAL FOR INTENSIFICATION ACCORDING TO THE GLOBAL MODELS...WITH STRONG SOUTHWESTERLY FLOW DEVELOPING OVER MARIA AHEAD OF THE LARGE MID/UPPER-LEVEL TROUGH MOVING OFF THE EAST COAST OF THE UNITED STATES. THE STATISTICAL GUIDANCE SUGGESTS SOME MODEST STRENGTHENING OVER THE NEXT COUPLE OF DAYS...AND THE OFFICIAL FORECAST IS CLOSE TO A BLEND OF THE SHIPS AND THE LGEM MODELS. MARIA SHOULD BE EXTRATROPICAL BY 72 HOURS...AND THE GLOBAL MODELS SHOW THE CYCLONE BEING ABSORBED BY A LARGER EXTRATROPICAL LOW BY 96 HOURS. THE INITIAL MOTION ESTIMATE IS 335/05. MARIA WILL ACCELERATE NORTHWARD AHEAD OF THE TROUGH MOVING OFF THE U.S. EAST COAST OVER THE NEXT COUPLE OF DAYS AND SHOULD TURN A LITTLE EAST OF DUE NORTH BY 48 HOURS. A FASTER NORTHEASTWARD MOTION IS EXPECTED BY 72 HOURS AS MARIA IS ABSORBED INTO THE MID-LATITUDE WESTERLIES. THE GUIDANCE REMAINS IN GOOD AGREEMENT ON THIS SCENARIO AND THE OFFICIAL FORECAST IS LARGELY AN UPDATE OF THE PREVIOUS ONE...LYING TO THE RIGHT OF THE MULTI-MODEL CONSENSUS BUT BETWEEN THE RELIABLE ECMWF AND GFS MODELS. FORECAST POSITIONS AND MAX WINDS INIT 13/1500Z 22.1N 68.0W 45 KT 50 MPH 12H 14/0000Z 23.6N 68.4W 45 KT 50 MPH 24H 14/1200Z 26.1N 68.8W 50 KT 60 MPH 36H 15/0000Z 29.2N 68.5W 55 KT 65 MPH 48H 15/1200Z 33.2N 67.0W 55 KT 65 MPH 72H 16/1200Z 43.0N 57.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 17/1200Z...ABSORBED $$ FORECASTER BRENNAN