000 WTNT44 KNHC 140235 TCDAT4 TROPICAL STORM MARIA DISCUSSION NUMBER 30 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011 1100 PM AST TUE SEP 13 2011 ALTHOUGH IT APPEARS THAT THE SHEAR OVER MARIA HAS AT LEAST TEMPORARILY ABATED...THE OVERALL ORGANIZATION OF THE CLOUD PATTERN HAS NOT IMPROVED SIGNIFICANTLY. THE LOW-LEVEL CENTER IS BELIEVED TO BE LOCATED NEAR THE NORTHWESTERN EDGE OF THE MAIN MASS OF DEEP CONVECTION. SATELLITE-BASED INTENSITY ESTIMATES FROM TAFB AND SAB ARE 55 KT AND 35 KT RESPECTIVELY...AND GIVEN THE LACK OF INCREASED ORGANIZATION...THE WIND SPEED IS KEPT AT 45 KT FOR THIS ADVISORY. NUMERICAL GUIDANCE INDICATES THAT THE SHEAR DOES NOT BECOME PROHIBITIVELY STRONG UNTIL ABOUT 48 HOURS...SO SOME STRENGTHENING COULD OCCUR PRIOR TO THAT TIME. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE LGEM GUIDANCE...AND TO THE PREVIOUS FORECAST. GLOBAL MODELS DEPICT MARIA BEGINNING TO LOSE TROPICAL CYCLONE STRUCTURE SOON AFTER 48 HOURS AS IT MERGES WITH A WELL-DEFINED BAROCLINIC ZONE. WITHIN 3 TO 4 DAYS...THE SYSTEM IS LIKELY TO BECOME ABSORBED BY A STRONG MID-LATITUDE LOW PRESSURE SYSTEM OVER EASTERN CANADA. THE BEST GUESS AT THE INITIAL MOTION IS A RATHER UNCERTAIN 350/8. THERE ARE NO IMPORTANT CHANGES TO THE EXPECTED STEERING PATTERN. OVER THE NEXT DAY OR SO...MARIA SHOULD MOVE GENERALLY NORTHWARD AT AN INCREASING FORWARD SPEED ALONG THE WESTERN SIDE OF A SUBTROPICAL HIGH PRESSURE AREA. BY 48 HOURS...A STRONG DEEP-LAYER TROUGH MOVING OVER THE NORTHEASTERN U.S. IS LIKELY TO CAUSE THE STORM TO TURN TOWARD THE NORTH-NORTHEAST WITH ADDITIONAL ACCELERATION. THE TRACK MODEL CONSENSUS HAS SHIFTED A LITTLE TO THE WEST ON THIS CYCLE...BUT VERY LITTLE ADJUSTMENT HAS BEEN MADE TO THE TRACK FORECAST FROM THE PREVIOUS ADVISORY. THE CURRENT NHC TRACK IS FAIRLY CLOSE TO THE GFS SOLUTION...ALTHOUGH NOT QUITE AS FAST. FORECAST POSITIONS AND MAX WINDS INIT 14/0300Z 23.5N 68.2W 45 KT 50 MPH 12H 14/1200Z 25.5N 68.5W 50 KT 60 MPH 24H 15/0000Z 28.8N 68.7W 50 KT 60 MPH 36H 15/1200Z 32.8N 67.7W 55 KT 65 MPH 48H 16/0000Z 38.0N 64.3W 55 KT 65 MPH 72H 17/0000Z 52.0N 50.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 96H 18/0000Z...ABSORBED $$ FORECASTER PASCH