000 AGXX40 KNHC 110646 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 150 AM EST THU NOV 11 2010 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A RIDGE AXIS WILL REMAIN OVER THE NORTHEASTERN GULF THROUGH MON. SE RETURN FLOW LIES OVER THE NW GULF AHEAD OF A WEAK FRONT OVER TEXAS. BUOY REPORTS OCCASIONALLY SHOWED WINDS TO 20 KT WED EVENING BUT HAVE MOSTLY SUBSIDED BELOW THAT THRESHOLD EXCEPT AT THE OBSERVATION SITES ON ELEVATED PLATFORMS. THE GFS AND ECMWF HAVE BOTH SLOWED DOWN THE TIMING OF THE FRONT AND NOW WAIT UNTIL CLOSER TO NOON ON SAT TO CARRY IT OFFSHORE. THESE MODELS STRAY FROM EACH OTHER CONSIDERABLY WITH THE FRONT SUN AND MON. THE GFS RETROGRADES THE FRONT BACK ONSHORE BY NOON SUN AND THEN ALLOWS A NEW SURGE OF COLD AIR TO BUILD BEHIND IT AND SEND IT OFFSHORE MON MORNING WHILE THE ECMWF ALLOWS IT TO HUG THE COAST MON. THE HPC MEDIUM RANGE PROGS FAVOR THE SLOWER ECMWF WHICH IS CLOSER TO THE GLOBAL MODEL CONSENSUS. THE FORECAST WILL BE ADJUSTED TOWARD THE ECMWF UNLESS THE 00Z RUN COMES IN CLOSER TO THE 00Z GFS. CARIBBEAN SEA... A STATIONARY FRONT LIES ACROSS PUERTO RICO INTO THE E CARIBBEAN. THE 0248 UTC ASCAT PASS AND MULTIPLE SHIP REPORTS SHOW WINDS W OF THE FRONT N OF 18N TO 20 KT...INCLUDING IN THE WINDWARD PASSAGE. THIS BOUNDARY WILL RECEIVE A REINFORCING SHOT OF COOLER AND DRIER AIR FROM THE NORTH ON FRI. WINDS ARE EXPECTED TO INCREASE TO 20 KT ALONG THE COAST OF NICARAGUA SAT AS THIS AIRMASS MOVES THROUGH THE WESTERN CARIBBEAN. MEANWHILE...THE MID LEVEL ENERGY ASSOCIATED WITH THE TAIL OF THE FRONT IS FORECAST BY MULTIPLE GLOBAL MODELS TO BE DRAWN WESTWARD TOWARD A DEVELOPING MONSOONAL GYRE OVER CENTRAL AMERICA. THE GFS SHOWS CONSIDERABLE DEVELOPMENT OF A LOW IN THE MID LEVELS THAT REFLECTS TO A 1007 MB SURFACE LOW WITH WINDS TO 30 KT BY SUN. THIS SOLUTION IS ON THE STRONGER END OF THE GLOBAL MODEL SUITE BECAUSE IT DRAWS A STRONG SHORTWAVE FROM THE EASTERN PACIFIC INTO THIS SYSTEM MORE QUICKLY THAN THE ECMWF AND THE UKMET SOLUTIONS. WHILE IT DOES HAVE SOME SUPPORT FROM THE CMC...IT IS WEAKER WITH THE SURFACE LOW THAN THE GFS. CONFIDENCE IS EXTREMELY LOW IN THE STRONG GFS SOLUTION. FOR NOW...WILL USE THE ECMWF FOR THE FORECAST. TROPICAL N ATLC... A STATIONARY FRONT LIES OVER THE FAR NW PORTION OF THE AREA WITH A 1009 MB LOW PRES NEAR 20N64W AND CONTINUES TO BRING SHOWERS AND THUNDERSTORMS AROUND PUERTO RICO AND THE VIRGIN ISLANDS. THIS CONVECTION IS FORECAST TO FINALLY THIN OUT OVER THE NEXT FEW DAYS AS THE MAIN SHORTWAVE SYSTEM SUPPORTING THE LOW IS DRAWN NORTHEASTWARD INTO THE LEADING EDGE OF THE DEEP LAYER LOW N OF BERMUDA. THE FRONT WILL BE REINVIGORATED BY FRI AND JOG TO THE S BY FRI AS THE SURFACE LOW ALONG THE BOUNDARY MOVES WELL N OF THE ZONE. THE FRONT SHOULD STALL ONCE AGAIN BY SAT AND DISSIPATE ON SUN. NW SWELL FROM THAT DEEP LAYER LOW WILL BUILD SEAS TO 12 FT IN THE NOW PORTION OF THE ZONE BY SAT AND GRADUALLY DAMPEN AS IT MOVES S THROUGH THE ZONE SUN. SW N ATLC... THE 0110 UTC ASCAT PASS SHOWS A SURGE OF 20-25 KT NW WINDS BEHIND A SECONDARY SURGE OF COLD AIR OVER NE WATERS ASSOCIATED WITH THE DEEP LAYER LOW N OF BERMUDA. 12 FT SEAS ARE CURRENTLY REPORTED AT BUOY 41048 JUST N OF THE AREA. THE SWELL FROM THIS STORM WILL BRING SEAS ABOVE 12 FT OVER MUCH OF THE AREA E OF THE BAHAMAS BY THE WEEKEND. A BLEND OF THE GFS AND ECMWF IS PREFERRED WITH THE DEEP LAYER LOW TO THE N OF THE FORECAST AREA. FURTHER S...20 KT NE WINDS CURRENTLY LIE N OF THE STATIONARY FRONT THAT CROSSES PUERTO RICO OVER WATERS N OF HISPANIOLA AND IN THE APPROACHES TO THE WINDWARD PASSAGE. THESE CONDITIONS SHOULD CONTINUE TODAY. THESE WINDS SHOULD DIMINISH SOMEWHAT LATER TODAY AHEAD OF THE SECONDARY SURGE OF COLD AIR THAT WILL PUSH THE FRONT EASTWARD AWAY FROM THE ZONE. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER