000 AGXX40 KNHC 030556 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 200 AM EDT WED MAY 02 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE TROUBLESOME LOW LEVEL TROUGH HAS MOVED INLAND LA AND AN ATLC RIDGE IS RE-ESTABLISHING WESTWARD ACROSS THE NORTHERN WATERS. DO NOT EXPECT MUCH CHANGE THROUGH EARLY FRI THEN A SURFACE HIGH WILL FORM ALONG THE RIDGE OVER THE NE WATERS. THE HIGH CENTER WILL DRIFT S THROUGH SUN THEN MEANDER OVER THE E WATERS THROUGH MON ALL THE WHILE EXTENDING A RIDGE NW TO THE TX/LA BORDER. LATEST GUIDANCE IS NOT AS AGGRESSIVE WITH THE SE RETURN FLOW OVER THE WESTERN GULF AND ONLY EXPECT IT PEAK AT 15 KT THROUGH THE PERIOD. THE ELY FLOW WILL CONTINUE AT 15-20 KT ACROSS THE FL STRAITS THROUGH TONIGHT...THEN DIMINISH TO LESS THAN 20 KT THROUGH THE REMAINDER OF THE PERIOD. GFS LOOKS OK WITH TIMING OF FEATURES...BUT CONTINUES THE ELY 20 KT WINDS OVER THE SE GULF A LITTLE TOO LONG...THUS WILL USE A BLEND OF ECM TO TWEAK THE SE FLOW FIRST 36 HOURS. SW N ATLC FROM 19N TO 31N W OF 55W... A FRONTAL TROUGH IS WASHING OUT ALONG 25N TO THE E OF 60W THIS MORNING. A SURFACE HIGH NEAR 29N73W WILL MEANDER OVER THE NW WATERS TODAY AS A COLD FRONT MOVES RAPIDLY SE INTO THE NE WATERS...AND STALLS TO THE E OF 70W ALONG 25N LATE FRI NIGHT...AND GRADUALLY DISSIPATES BETWEEN 60W AND 55W THROUGH MON. THE SURFACE HIGH WILL SHIFT SE TO NEAR THE NW BAHAMAS FRI NIGHT...CONTINUING SE TO NEAR 25N71W SAT NIGHT WITH A RIDGE E-W ALONG 25N TO THE W OF 60W. THE RIDGE WILL CONTINUE TO SHIFT S ON SUN AND MON BECOMING ORIENTATED FROM W TO E FROM THE PARENT HIGH THEN CENTERED IN THE EASTERN GULF OF MEXICO. AS THE ATLC HIGH SHIFTS S...A STRONGER COLD FRONT...ACCOMPANIED BY CONVECTION... WILL MOVE INTO THE N WATERS SAT...REACHING FROM BERMUDA TO THE NW BAHAMAS SUN...AND FROM 31N55W TO THE SE BAHAMAS ON MON. CARIBBEAN SEA AND TROPICAL ATLC S OF 19N W OF 55W... ELY TRADES PULSING AT 15-20 KT ACROSS THE CENTRAL CARIBBEAN WILL DIMINISH FROM THE N TO THE S REACHING 10-15 KT TODAY...WITH THE SAME FORECAST ELSEWHERE ELSE...AND LITTLE CHANGE EXPECTED THROUGH EARLY FRI. CONVECTION NEAR THE VIRGIN ISLANDS MAY ALREADY BE INDUCING THE SURFACE TROUGH THAT GUIDANCE HAS BEEN SUGGESTING TO DEVELOP ON FRI. THE TROUGH WILL GRADUALLY AMPLIFY SW REACHING TO THE N COAST OF COLOMBIA...THEN DRIFT SLOWLY W THROUGH THE WEEKEND. THE GFS AND THE ECM...BUT NOT THE UKMET... IS NOW SUGGESTING A LOW MAY DEVELOP OVER THE E CARIBBEAN ALONG THE TROUGH LATE IN THE WEEKEND...AND MOVE N ALONG ITS AXIS... ACROSS THE SOUTHERN LEEWARDS LATE MON. 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 (LOWER CASE). GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER NELSON