000 AGXX40 KNHC 140721 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 325 AM EDT WED APR 14 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W SW N ATLC AND TROPICAL ATLC... MEAN TROUGHING THROUGH THE WESTERN N ATLC WILL AMPLIFY THIS PERIOD...SWEEPING THE STRONG SHORTWAVE SYSTEM CURRENTLY N OF THE BAHAMAS IN THE SW N ATLC ZONE EASTWARD ALONG 25N AND SHOVING THE LINGERING MID LEVEL ENERGY CURRENTLY N OF THE LESSER ANTILLES EASTWARD INTO THE LEADING EDGE OF THE AMPLIFYING MEAN TROUGH. THE MODELS AGREE ON DEVELOPING A SURFACE REFLECTION OF THIS MID LEVEL ENERGY...BUT VARY WITH THE STRENGTH OF THE WAVE AND THE TIMING AT WHICH THE WAVE LIFTS NORTHWARD AND BECOMES INGESTED IN THE ANCHOR LOW DEVELOPING IN THE CENTRAL ATLC WELL N OF THE AREA. THE PREVIOUS FORECAST THINKING KEPT THIS REFLECTION AS A TROUGH AT THE SURFACE. CONFIDENCE IS LOW IN THE DETAILS WITH THIS SYSTEM. FOR NOW...THE FORECAST NODS TOWARD CONTINUITY AND SIDES WITH THE WEAKER END OF THE GUIDANCE WITH THE SURFACE WAVE. THIS IS MOST IN LINE WITH THE UKMET. HOWEVER...THE FORECAST EDGES CLOSER TO THE MODEL CONSENSUS WITH THE TIMING LIFTING THE WAVE NORTHWARD. AS THE MEAN TROUGH SHIFTS EASTWARD...DEEP HIGH PRES OVER THE APPALACHIAN MOUNTAINS AND MID ATLANTIC U.S. STATES WILL WEAKEN AND MOVE INTO NW WATERS. THE E TO W ORIENTED SURFACE RIDGE WILL MOVE S OF 30N ON FRI AND ALONG 27N SAT WITH THE SURFACE HIGH SHIFTING E OF AREA ON SUN. THE MODELS ARE IN REASONABLE AGREEMENT ON CARRYING A WEAK COLD FRONT INTO NW WATERS ON SUN. CARIBBEAN... THE PRES GRADIENT BETWEEN STRONG HIGH PRES N OF THE AREA AND BROAD LOW PRES OVER THE SOUTHERN AND EASTERN CARIBBEAN IS BRINGING INCREASINGLY STRONG E WINDS ACROSS THE NW CARIBBEAN. THE 0216 UTC ASCAT PASS SHOWED NE WINDS TO 25 KT JUST S OF CUBA E OF 81W. THIS PATTERN IS EXPECTED TO CONTINUE INTO FRI WITH WINDS DIMINISHING AS THE HIGH PRES SYSTEM SHIFTS SE. THE FORECAST IN THE EASTERN CARIBBEAN IS CLOSELY TIED TO THE EVOLUTION OF THE WAVE ALONG THE TROUGH OVER THE WESTERN N ATLC. THE PREFERRED FORECAST IS WEAKER AND SLOWER THAN THE GFS SOLUTION. THIS ALLOWS WINDS TO REMAIN LESS THAN 20 KT UNTIL THU WHEN THE SURFACE WAVE MOVES AWAY FROM THE CARIBBEAN AND HIGH PRES MOVES IN INCREASING NE WINDS TO 20 KT THROUGH THE NE CARIBBEAN INTO SAT BEFORE THE HIGH PRES SYSTEM APPROACHES THE AREA...DROPPING WINDS A NOTCH AND TURNING THEM MORE EASTERLY SUN. GULF OF MEXICO... ASCAT PASSES FROM 0218 AND 0358 UTC AND MORE RECENT SURFACE OBSERVATIONS SHOW E WINDS ACROSS THE EASTERN AND NW GULF IN THE 20 TO 25 KT RANGE. THESE STRONG WINDS ARE ON THE S EDGE OF A STRONG HIGH PRES RIDGE THAT WILL SHIFT SE INTO THE SW N ATLC FRI AND CONTINUE SE THROUGH THE WEEKEND. THE STRONG WINDS WILL DIMINISH OVER THE FAR EASTERN GULF AS THE SURFACE RIDGE MOVES SOUTHWARD INTO THE AREA...BUT WINDS WILL REMAIN STRONG OVER THE CENTRAL GULF. CONFIDENCE DROPS OFF SIGNIFICANTLY IN THE FORECAST BY THE WEEKEND WHEN THE GFS AND CMC CARRY AN SURFACE WAVE EASTWARD ACROSS THE SOUTHERN GULF. THE ECMWF AND UKMET AGREE ON INCREASED TROUGHING ACROSS THE SOUTHERN GULF...BUT ARE ABOUT 12-24 HOURS SLOWER AND CONSIDERABLY WEAKER WITH THE TROUGHING COMPARED TO THE GFS. CONFIDENCE IS LOW IN THE GFS SOLUTION WHICH DEVELOPS A 1008 MB LOW OVER THE S CENTRAL GULF SAT NIGHT. THE FORECAST MORE CLOSELY FOLLOWS THE WEAKER ECMWF/UKMET SOLUTION. AT THE SAME TIME...THE MODELS ARE IN REASONABLE AGREEMENT ON CARRYING A WEAK COLD FRONT TO THE GULF COASTAL PLAIN ON SUN WITH LITTLE FANFARE. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER