000 AGXX40 KNHC 091831 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 PM EDT WED MAY 9 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A WEAK COLD FRONT EXTENDS ACROSS THE NW GULF FROM MISSISSIPPI TO BROWNSVILLE TX. WINDS ARE LIGHT AND VARIABLE ALONG THE FRONT AND N-NE AT 10-15 KT BEHIND IT. THE FRONT WILL SAG EASTWARD THIS EVENING WITH FEW SHOWERS AND TSTMS...PRIMARILY AS A SHIFT IN WIND DIRECTION. A SURGE OF COOLER AIR ALONG THE EASTERN SEABOARD WILL PUSH THE FRONT ACROSS THE FLORIDA PENINSULA TONIGHT WHILE THE W PORTION OF THE FRONT BECOMES DIFFUSE FROM SARASOTA TO 26N87W THU MORNING. THE GFS CONTINUES TO BE AN OUTLIER MODEL BY INTENSIFYING A MID LEVEL VORTICITY CENTER ON THE LEADING EDGE OF A LOW IN THE NW GULF...GENERATING GALE FORCE WINDS FRI AFTERNOON THROUGH EARLY SAT MORNING...THEN TRACKS THE LOW PRES SYSTEM OFF THE TX COAST SAT MORNING INTO SOUTHERN LA SUN. MEANWHILE...ECMWF NEVER GENERATES WINDS STRONGER THAN 20 KT AND KEEPS THE SURFACE LOW INLAND. THE UKMET LOOKS LIKE A GOOD COMPROMISE WITH THE WIND SPEEDS...MAXING OUT AT 25 KT...BUT CARRIES A LOW ALONG THE GFS TRACK. WITH BOTH THE ECMWF ENS MEAN AND THE GEFS KEEPING THE LOW TRACK ALONG THE COAST...THE ECMWF SOLUTION APPEARS TO NOT HAVE MUCH SUPPORT. THE UKMET SEEMS TO BE A COMPROMISE SOLUTION...AND WILL BE USED FOR PRIMARY BASIS OF GRIDS FRI THROUGH SUN. CARIBBEAN SEA AND TROPICAL N ATLC... A WEAK TROUGH CONTINUES TO LINGER IN THE EAST-CENTRAL CARIBBEAN. THE TROUGH WILL MIGRATE INTO THE CENTRAL CARIBBEAN THROUGH SAT WHEN IT WILL BEGIN TO LIFT NORTHWARD IN ADVANCE OF A COLD FRONT OVER THE SW N ATLC. RIDGING WILL BUILD OVER THE CENTRAL ATLC THU WITH WINDS INCREASING TO 20 KT OVER THE TROPICAL N ATLC AND E CARIBBEAN AS THE PRES GRADIENT TIGHTENS. THE ECMWF AND GFS ARE IN REASONABLY GOOD AGREEMENT WHILE THE UKMET BUILDS THE PRES GRADIENT FARTHER NE OVER THE TROPICAL N ATLC. A BLEND OF THE GFS AND ECMWF WAS USED TO ADJUST THE GRIDS THROUGH SUN. THE PRES GRADIENT WILL TIGHTEN IN THE GULF OF HONDURAS THU NIGHT THROUGH SUN MORNING...SUPPORTING 20 KT WINDS AS TROUGHING BUILDS OVER THE WESTERN GULF OF MEXICO. SW N ATLANTIC... SATELLITE IMAGERY SHOWS A LOW PRES CENTERED NEAR 29N70W BECOMING LESS DEFINED OVER THE PAST 12 HOURS. SURFACE OBS AND ASCAT DATA INDICATE 15 TO 20 KT WINDS AROUND IT. THE LOW WILL MOVE NORTHWARD AHEAD OF THE COLD FRONT IN THE GULF OF MEXICO AND DISSIPATE LATE TONIGHT. GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THE TIMING AND STRENGTH OF THE COLD FRONT AS IT REACHES THE SW N ATLC. EXPECT 20-25 KT SW WINDS IMMEDIATELY AHEAD OF THE FRONT...WITH SEAS TO 7-8 FT THU THROUGH FRI. NOTE... EFFECTIVE APR 3 2012 AT 1800 UTC THE OFFSHORE WATERS FORECAST ZONES CHANGED FOR THE CARIBBEAN AND SW N ATLANTIC AND THE GULF OF MEXICO. ISSUANCE TIME FOR THE GULF OF MEXICO OFFSHORE WATERS FORECASTS IS REFERENCED TO THE EASTERN TIME ZONE. FOR DETAILS SEE WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER MUNDELL