000 WTNT44 KNHC 132041 TCDAT4 TROPICAL STORM HUMBERTO DISCUSSION NUMBER 21 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 500 PM AST FRI SEP 13 2013 DEEP CONVECTION HAS BEEN STRUGGLING TO REDEVELOP NEAR HUMBERTO IN THE FACE OF SOME RATHER STRONG SHEAR. DVORAK CONSTRAINTS SUGGEST AN INITIAL INTENSITY OF ABOUT 45 KT...THOUGH THIS COULD BE REFINED A BIT AFTER THE NEXT SCATTEROMETER PASS. AN EXTREMELY LARGE UPPER- LEVEL TROUGH OVER THE CENTRAL ATLANTIC IS CONTINUING TO SHEAR HUMBERTO. THIS SHEAR IS NOT FORECAST TO ABATE FOR A COUPLE OF DAYS...AND IT WOULD NOT BE SURPRISING TO SEE HUMBERTO DROP TO A TROPICAL DEPRESSION AT SOME POINT DURING THAT TIME. HOWEVER...THE GLOBAL MODELS CONTINUE TO INSIST THAT THE STORM WILL FIND A MORE FAVORABLE ENVIRONMENT FOR STRENGTHENING...AND MOST OF THE RELIABLE GUIDANCE SHOWS HUMBERTO AS A HURRICANE AGAIN BY DAY 5. THE INTENSITY FORECAST IS AGAIN REDUCED IN THE SHORTER TERM...BUT IS KEPT THE SAME AT THE END. THE MOTION HAS SHIFTED A BIT FARTHER TO THE LEFT...NOW 290/10. THERE IS NO CHANGE TO THE SYNOPTIC REASONING FOR THE NEXT FEW DAYS WHILE A STRONG RIDGE STEERS THE STORM BASICALLY WEST-NORTHWESTWARD. THERE CONTINUE TO BE LARGE MODEL DIFFERENCES AS TO HOW FAST HUMBERTO RECURVES OUT TO SEA...WITH THE GFS/GEFS SUGGESTING A MUCH FASTER TRACK THAN MOST OF THE OTHER MODELS. OVERALL...THE GUIDANCE IS TRENDING A LITTLE TO THE SOUTHWEST...AND THE OFFICIAL FORECAST IS SHIFTED IN THAT WAY...FAIRLY CLOSE TO A BLEND OF THE FLORIDA STATE SUPERENSEMBLE AND THE DYNAMICAL MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 13/2100Z 25.0N 32.1W 45 KT 50 MPH 12H 14/0600Z 25.4N 33.7W 40 KT 45 MPH 24H 14/1800Z 26.3N 36.1W 35 KT 40 MPH 36H 15/0600Z 27.3N 38.4W 35 KT 40 MPH 48H 15/1800Z 28.2N 40.4W 35 KT 40 MPH 72H 16/1800Z 30.4N 43.3W 40 KT 45 MPH 96H 17/1800Z 32.5N 45.3W 55 KT 65 MPH 120H 18/1800Z 36.0N 45.0W 65 KT 75 MPH $$ FORECASTER BLAKE