000 AGXX40 KNHC 030708 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 310 AM EDT TUE MAY 3 2011 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. SW N ATLC AND TROPICAL N ATLC... A LOW PRES SYSTEM DEEPENING N OF THE AREA IS EXPECTED TO DROP S OF 30N OVERNIGHT WED NIGHT INTO THE AREA JUST E OF 55W. THE 00Z GFS FORECAST FOR THE SYSTEM IS EXPECTED TO BE OVER 6 STANDARD DEVIATIONS DEEPER THAN THE MEAN PATTERN AT H5 AT THAT TIME. WHILE THIS IS A HIGHLY UNUSUAL PATTERN...THE GFS IS IN REASONABLE AGREEMENT WITH THE 00Z ECMWF ON THE DEPTH OF THE SYSTEM BUT BECOMES MORE WESTERLY WITH THE DEEP LAYER LOW BY THU THAN THE OTHER MODELS. THEREFORE...WILL LEAN MORE ON THE GFS SOLUTION. NORTHERLY SWELL ASSOCIATED WITH THIS SYSTEM WILL CONTINUE MAKING ITS WAY SOUTHWARD THROUGH THE EASTERN WATERS OF THE SW N ATLC TODAY THROUGH WED AND DAMPEN AS IT MOVES THROUGH THE TROPICAL N ATLC WED THROUGH FRI. THIS SYSTEM WILL CONTINUE TO DISRUPT THE SUBTROPICAL RIDGE AND ASSOCIATED TRADE WINDS OVER THE TROPICAL N ATLC THROUGH THE PERIOD. HIGH PRES BEHIND THIS SYSTEM WILL REMAIN ANCHORED N OF THE AREA UNTIL WED WHEN A NEW COLD FRONT MOVES OFF THE N FL COAST. THE 00Z GFS AND ECMWF ARE IN REASONABLE AGREEMENT AND IN LINE WITH THE MODEL CONSENSUS WITH THE FRONTAL TIMING AND DISINTEGRATION W OF 55W. CARIBBEAN... RAINFALL WILL CONTINUE TO BE THE MAIN WEATHER STORY OVER THE CARIBBEAN THIS FORECAST PERIOD. PRECIPITABLE WATER IMAGERY SHOWS THE SLUG OF MOISTURE SPREADING EASTWARD INTO THE CENTRAL CARIBBEAN MAINLY BEHIND THE SURFACE TROUGH THAT IS STRETCHING THROUGH CENTRAL HISPANIOLA. PRECIPITATION HAS SPREAD EASTWARD AS WELL...WITH ISOLATED SHOWERS SEEN NEAR MDSD...MDPP...AND MDPC IN THE DOMINICAN REPUBLIC OVER THE LAST 6-12 HOURS. PRECIPITABLE WATER VALUES AT OR ABOVE 50 MILLIMETERS ARE EXPECTED TO STRETCH INTO THE SW CARIBBEAN OVER THE NEXT FEW DAYS AS THE MID-LEVEL REMNANTS OF THE COLD FRONT OVER THE SW N ATLC SWING S AND CONTAIN THE MOISTURE OVER THE CARIBBEAN. UPPER LEVEL DIFFLUENT FLOW ASSOCIATED WITH THE REAR RIGHT QUADRANT OF A LINGERING UPPER JET WILL ALLOW FOR VERTICAL LIFT OF THIS MOISTURE WHICH SHOULD ENHANCE PRECIPITATION OVER THE EASTERN CARIBBEAN AND CENTRAL CARIBBEAN INCLUDING HISPANIOLA THROUGH WED. AN INCREASE IN PRECIPITATION IS ALSO EXPECTED IN THE SW CARIBBEAN PRIMARILY LATER TODAY THROUGH FRI. THE SHIPS ZCDF4 AND 8PNQ HAVE REPORTED 30 KT WINDS IN THE WINDWARD PASSAGE OVER THE LAST FEW HOURS. NONE OF THE MODELS ARE SHOWING WINDS THIS HIGH...WITH THE 00Z GFS AND ECMWF ONLY SHOWING WINDS TO 25 KT. A BEEFED UP VERSION OF THE GFS WILL BE USED HERE THROUGH THE PASSAGE OF THE TROUGH CURRENTLY OVER HISPANIOLA LATE WED AND UNTIL THE NEXT FRONT APPROACHES ON FRI. GULF OF MEXICO... THE COLD FRONT HAS MOVED INTO THE WESTERN GULF FROM SW LOUISIANA THROUGH TAMPICO MEXICO AND INTO THE FAR WESTERN BAY OF CAMPECHE. THE 0312 UTC ASCAT PASS CAPTURED THE FRONTAL POSITION AT THAT TIME AND SHOWED WINDS TO 30 KT NEAR THE MEXICAN COAST BEHIND THE FRONT. THE 00Z GFS AND UKMET SHOW WINDS TO MINIMAL GALE FORCE ALONG THE MEXICAN COAST TODAY WHILE THE 00Z ECMWF AND NOGAPS REMAIN BELOW GALE. THE 18Z GEFS SHOWED A VERY SLIGHT CHANCE OF A GALE AT 1200 UTC TODAY...BUT THAT CHANCE HAS DROPPED OFF TO A ZERO PERCENT CHANCE IN THE 00Z GEFS. THE GENERAL TREND IN THE GFS ENSEMBLES HAS BEEN TOWARD WEAKER WINDS BEHIND THIS FRONT. SEA SURFACE TEMPERATURES IN THE NEAR SHORE WATERS OF THE FAR WESTERN GULF ARE COOLER THAN THE WATER OFFSHORE N OF 20N. THIS IS AN INDICATION THAT THE STRONGEST WINDS MAY HAVE A HARDER TIME MIXING DOWN TO THE SURFACE. THEREFORE...WILL NOT ISSUE A GALE WARNING BEHIND THE FRONT. IF WINDS WERE TO GET TO GALE FORCE...THE MOST LIKELY PLACE APPEARS TO BE ALONG THE IMMEDIATE COAST S OF 20N WHERE WATER TEMPS ARE WARMER AND FUNNELING INDUCED BY TERRAIN CAN ENHANCE WINDS. WARNINGS.. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER