000 AGXX40 KNHC 070728 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 330 AM EDT WED OCT 07 2009 GULF OF MEXICO... SOUTHERLY RETURN FLOW TO 20 KT CAN CURRENTLY BE FOUND OVER THE NW GULF AHEAD OF THE COLD FRONT OVER TX. THE FRONT IS EXPECTED TO REMAIN N OF THE GULF OF MEXICO...PASSING THROUGH THE SOUTHEAST U.S. AND INTO THE WESTERN N ATLC WED. STRONG HIGH PRES BEHIND THIS COLD FRONT WILL BE SLOW TO MOVE OFF THE CAROLINA COAST...ALLOWING FOR MEAN HIGH PRES TO REMAIN OVER EASTERN GULF THU AND FRI. A NEW TROUGH WILL MOVE INTO THE PLAINS STATES THU AND INITIATE SOUTHERLY RETURN FLOW OVER THE GULF WHERE THE PRES GRADIENT WILL BE ENHANCED BETWEEN THIS TROUGHING AND THE RIDGING OVER THE E GULF. THE GFS...ECMWF...AND UKMET CONTINUE TO SHOW WINDS BRIEFLY REACHING 25 KT AHEAD OF THE FRONT. THE MODELS HAVE GENERALLY BEEN TOO STRONG WITH THE RETURN FLOW OVER THE NW GULF IN THE FORECAST PERIOD UNDER THIS PATTERN...BACKING OFF AS THE EVENT DRAWS CLOSER. THE MODELS AGREE ON DEVELOPING A SURFACE WAVE ALONG THE FRONT OVER THE SE U.S. BY SAT WHICH WILL HOLD UP ITS SOUTHEASTWARD PROGRESS. THE GFS BARELY DIPS THE FRONT INTO THE GULF WHILE THE OTHER MODELS ARE MORE ADAMANT ABOUT THE FRONT PASSING WELL INTO THE NW GULF ZONE SAT BEFORE STALLING. FORECAST FOLLOWS THIS MORE SOUTHERLY MODEL CONSENSUS. CARIBBEAN AND TROPICAL N ATLC... TROPICAL STORM HENRI AT 18.4N 55.3W AT 0300 UTC WITH WINDS OF 40 KT WITHIN GUSTS TO 50 KT IS FORECAST TO WEAKEN TO A MINIMAL TROPICAL STORM NEAR 18.4N 55.3W WED MORNING AND WEAKEN FURTHER TO A 30 KT DEPRESSION BY 20.5N59/7W WED NIGHT BEFORE DIMINISHING TO A REMNANT LOW NEAR 21.8N 61.9W THU MORNING AS A HIGHLY AMPLIFIED NORTHERN STREAM TROUGH SWEEPS THROUGH THE CENTRAL N ATLC. WINDS AND SEAS ASSOCIATED WITH HENRI SHOULD DIMINISH BELOW 20 KT/8 FT CRITERIA OVER THE TROPICAL N ATLC ZONE AROUND MID-DAY THU. THE QUIKSCAT PASS FROM 2332 UTC SHOWS WINDS INTO THE 20 TO 25 KT RANGE CONTINUE ALONG THE COAST OF COLOMBIA COURTESY OF THE RIDGE TO THE NORTH AND ASSOCIATED 1019 MB HIGH PRES NEAR 27N66W THAT HAS INCREASED THE PRES GRADIENT OVER THE CENTRAL CARIBBEAN. A TROPICAL WAVE CURRENTLY ALONG 66W S OF 15N WILL TRACK THROUGH THE CENTRAL CARIBBEAN WED AND WILL EXIT THE CARIBBEAN FRI. ANOTHER TROPICAL WAVE ALONG 42W S OF 10N WILL LIFT NORTH AS IT TRAVELS W UNDER A WEAKNESS IN THE SUBTROPICAL RIDGE. THE WAVE IS EXPECTED TO REACH THE CARIBBEAN FRI. THE 0042 UTC QUIKSCAT PASS SHOWS WINDS IN THE 20 TO 25 KT RANGE N OF WHERE THE WAVE INTERSECTS THE ITCZ AT 08N. THE PRES GRADIENT HERE IS STRONG AS THE 1022 MB HIGH PRES SYSTEM NEAR 25N40W HAS A RIDGE AXIS THAT EXTENDS JUST TO THE NE OF THE LOW AND ON THE E SIDE OF HENRI WITH THE 1016 MB LINE DROPPING S OF 12N. THIS WAVE WILL REACH FORECAST WATERS BY THU AND PASS INTO THE CARIBBEAN FRI. SW N ATLC... A 1010 MB LOW PRES SYSTEM OFF THE NC COAST WILL CONTINUE TO PUSH NE DRAGGING ITS ASSOCIATED STATIONARY FRONT OUT OF NW WATERS LATER TODAY. THIS SYSTEM IS MOVING NE ON THE LEADING EDGE OF THE BROAD DEEP LAYER TROUGH PASSING E OF THE MISSISSIPPI RIVER. THE COLD FRONT ASSOCIATED WITH THE DEEP LAYER TROUGH WILL MOVE INTO N WATERS OVERNIGHT TONIGHT AND SW WINDS AHEAD OF THE FRONT WILL INCREASE TO 20 KT OVER FAR NW WATERS AND WILL SHIFT E ACROSS FAR N FORECAST WATERS AS THE FRONT MOVES OFFSHORE THROUGH THU. THE FRONT WILL DIP INTO N WATERS THU AND FRI...SHIFTING WINDS NORTHEASTERLY. THE FRONT WILL MOVE E OF THE AREA AND HIGH PRES WILL BUILD FROM THE N ON FRI. THIS FRONT WILL PREVENT THE REMNANTS OF HENRI FROM IMPACTING THE SW N ATLC ZONE...DRAGGING WHAT IS LEFT OF HENRI NE BY FRI IF THE CURRENT GFS/ECMWF FORECAST HOLDS TRUE. IT SHOULD BE NOTED THAT THE NOGAPS/CMC/UKMET ALL AGREE ON CARRYING THE REMNANT LOW TO NEAR 20N65W FRI NIGHT AND CARRY IT W TOWARD THE SOUTHERN BAHAMAS OVER THE WEEKEND. FINALLY...ANOTHER COLD FRONT WILL APPROACH NW WATERS AT THE END OF THE FORECAST PERIOD. THE MODELS AGREE ON DEVELOPING A SURFACE WAVE ALONG THE FRONT OVER THE SE U.S. BY SAT WHICH WILL HOLD UP ITS EASTWARD PROGRESS. THE ECMWF IS WEAKER WITH THE LOW AND FASTER WITH THE FRONT COMPARED TO THE GFS...BUT THE GFS DEVELOPS A STRONGER SURFACE RIDGE OVER SE GA THAN THE OTHER MODELS AND MAY BE TOO SLOW AS A RESULT. A BLEND OF THESE SOLUTIONS WAS USED FOR THE FORECAST. WARNINGS... ATLC... .TROPICAL STORM WARNING...AMZ087. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE $$ FORECASTER SCHAUER CLARK