000 AGXX40 KNHC 050723 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 330 AM EDT MON OCT 05 2009 GULF OF MEXICO... 1007 MB LOW PRES OVER THE LOWER MISSISSIPPI VALLEY IS EXPECTED TO SHIFT EASTWARD TODAY. SOUTHERLY WINDS INFLOW INTO THE LOW...CURRENTLY TO 20 KT IN THE N CENTRAL GULF...SHOULD DIMINISH THIS MORNING WHEN THE LOW SHIFTS NE AWAY FROM THE REGION. HIGH PRES BUILDS W ACROSS THE GULF OF MEXICO EARLY NEXT WEEK. A DEEP LAYER LOW MOVES INTO THE CENTRAL PLAINS BY TUE...WITH THE COLD FRONT PUSHING INTO TX. AT THE SAME TIME...HIGH PRES IS EXPECTED TO BUILD OVER THE NE GULF. THIS WILL INCREASE THE PRES GRADIENT OVER THE NW GULF AND SOUTHERLY RETURN FLOW WILL INCREASE TO 20 KT TUE. THIS FRONT IS EXPECTED TO REMAIN N OF THE GULF OF MEXICO...STRETCHING THROUGH THE SOUTHEAST U.S. AND INTO THE WESTERN N ATLC BY 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. ALSO THU...A NEW TROUGH WILL MOVE INTO THE PLAINS STATES 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. GFS SHOWS WINDS REACHING THE 25-30 KT RANGE FRI...BUT THIS SEEMS OVER DONE COMPARED TO THE MODEL CONSENSUS. 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. CARIBBEAN AND TROPICAL N ATLC... THE QUIKSCAT PASS FROM 2244 UTC SHOWS WINDS INTO THE 20 TO 25 KT RANGE WITHIN 360 NM E OF THE TROPICAL WAVE ALONG 79W FROM 12N TO 16N. SHIP OBSERVATION A8JP4 CONFIRMS THE 25 KT WINDS. LOOK FOR THESE STRONGEST WINDS IN THE CARIBBEAN TO SHIFT FROM THE CENTRAL CARIBBEAN W INTO THE NW CARIBBEAN TODAY THROUGH TUE AS THE TROPICAL WAVE MAKES ITS WAY TOWARD CENTRAL AMERICA. A SLOW MOVING TROUGH OVER THE NE CARIBBEAN ALONG 63W FROM 14N TO 20N IS EXPECTED TO WEAKEN AS IT MOVES SLOWLY NW INTO THE GREATER ANTILLES AND BAHAMAS OVER THE NEXT FEW DAYS. CONVECTION ASSOCIATED WITH THIS TROUGH MAY MAKE IT MORE CHALLENGING TO TRACK THE TROPICAL WAVE CURRENTLY ALONG 56W S OF 15N AS IT TRACKS INTO THE E CARIBBEAN. THIS TROPICAL WAVE IS EXPECTED TO MOVE TROUGH THE TROPICAL N ATLC ZONE TODAY AND PASS INTO THE EASTERN CARIBBEAN BY TUE. ANOTHER TROPICAL WAVE ALONG 42W S OF 15N WILL MOVE INTO THE TROPICAL N ATLC ZONE BY TUE. THIS WAVE HAS MODERATE TO STRONG CONVECTION WITHIN 150 NM OF THE WAVE AXIS FROM 09N TO 16N AND THE 2344 UTC ASCAT PASS SHOWS WINDS IN THE 20 TO 25 KT RANGE ASSOCIATED WITH THE NORTHERN QUARTER OF THE WAVE. BUOY 41041 SAW WINDS IN THE 20-25 KT RANGE AND SEAS TO 8 FT AT 0300 UTC. THE MODELS SHOW SOME DEVELOPMENT OF THIS SYSTEM AS IT APPROACHES A WEAKNESS IN THE SUBTROPICAL RIDGE E OF THE LESSER ANTILLES AND LIFTS NORTHWARD. THE FORECAST IS CLOSE TO THE ECMWF...DEVELOPING A 1014 MB SURFACE LOW ALONG THE TROPICAL WAVE BY TUE NIGHT NEAR 16N55W AND SPLINTERING THIS LOW OFF FROM THE TROPICAL WAVE AND TRACKING IT NW...PASSING N OF PUERTO RICO AND INTO THE SW N ATLC ZONE ON FRI. THE PARENT TROPICAL WAVE WILL CONTINUE W INTO THE CARIBBEAN WED NIGHT THROUGH FRI. SW N ATLC... THE SURFACE COLD FRONT CURRENTLY OVER NW WATERS WILL DISSIPATE WITH LITTLE FANFARE BY MORNING. THE REMAINING WARM FRONT ON ITS TAIL END FARTHER W IS ANCHORED BY 1007 MB LOW PRES OVER THE LOWER MISSISSIPPI VALLEY AND WILL MOVE THROUGH THE SE U.S...SHIFT NE OFF THE CAROLINA COAST...AND SLOWLY CARRY A COLD FRONT AND A REINFORCING PUSH SOUTHEASTWARD TUE-THU. SW WINDS AHEAD OF THIS SYSTEM WILL INCREASE TO 20 KT OVER FAR NW WATERS BY TUE EVE AS A RESULT 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. HIGH PRES WILL BUILD FROM THE N ON FRI WHILE A NEW SURFACE LOW TRACKS W-NW INTO THE SE PORTION OF THE ZONE AT THE END OF THE PERIOD. SEE DISCUSSION ABOVE FOR DETAILS. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE $$ FORECASTER LL