000 AGXX40 KNHC 220701 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 300 AM EST MON MAR 22 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... THE STRONG COLD FRONT HAS EXITED THE GULF OF MEXICO. THE 0334 UTC ASCAT PASS SHOWS WINDS N OF 26N IN THE 25-30 KT RANGE IN THE N CENTRAL GULF AND THERE ARE A FEW STATIONS...MOST OF WHICH ARE ELEVATED MORE THAN 10 M ABOVE THE SEA SURFACE...REPORTING WINDS IN THIS RANGE. SEAS REMAIN AS HIGH AS 13-14 FT N OF 25N ALONG 86W. THE 1024 MB HIGH PRESSURE CURRENTLY OVER THE SE GULF WILL WEAKEN AND SHIFT NE ACROSS THE CENTRAL GULF TODAY AND TUE WITH RETURN FLOW INCREASING AGAIN IN THE W GULF TUE AND WED. A NEW COLD FRONT WILL MOVE OFF NW GULF COAST THU MORNING...BUT IT WILL NOT BE AS STRONG AS THE PREVIOUS SYSTEM AND GALES ARE NOT EXPECTED. THE LONGWAVE PATTERN IS EXPECTED TO BECOME INCREASINGLY LESS AMPLIFIED AND MORE PROGRESSIVE. HOWEVER...THE PMDHMD EXPLAINS THAT THE MODELS MAY BE TOO FAST TO BREAK DOWN THE AMPLIFIED RIDGE DOWNSTREAM OF THIS SYSTEM. THE FORECAST MOST CLOSELY RESEMBLES THE 0000 UTC GFS THAN THE MORE PROGRESSIVE ECMWF AND UKMET MODELS AS A RESULT. THIS FORECAST CARRIES THE FRONT FROM THE NE GULF INTO THE YUCATAN PENINSULA BY THE END OF THE FORECAST PERIOD ON FRI NIGHT. TROPICAL ATLC AND CARIBBEAN SEA... A COLD FRONT PASSED SE FROM THE GULF OF MEXICO INTO THE NW CARIBBEAN SUN EVENING. WINDS AT BUOY 42056 INCREASED FROM LESS THAN 10 KT TO N-NW AT 23 KT BETWEEN 0100 UTC AND 0200 UTC BEHIND THE FRONT. THIS FRONT WILL BRIEFLY DIP INTO THE FAR SW CARIBBEAN TONIGHT BEFORE LIFTING N AND DISSIPATING OVER THE NW CARIBBEAN BY WED MORNING. RETURN FLOW TURNS WINDS IN THE NW CARIBBEAN MORE SOUTHEASTERLY ON THU AHEAD OF THE SYSTEM PASSING INTO THE NW GULF OF MEXICO. STICKING WITH THE HPC DECISION EXPLAINED IN THE PMDHMD TO FAVOR THE SLOWER GFS SOLUTION OVER THE ECMWF/UKMET WITH THE FRONT PASSING THROUGH THE GULF THU-FRI. THIS SOLUTION PREVENTS THE FRONT FROM MOVING INTO THE NW CARIBBEAN BEFORE THE END OF THE FORECAST PERIOD FRI NIGHT. ELSEWHERE IN THE CARIBBEAN...THE ASCAT PASS FROM 0150 UTC SHOWED A SOLID AREA OF 25 TO 30 KT WINDS S OF 15N BETWEEN 70W AND 75W NEAR THE COAST OF COLOMBIA. STRONG EASTERLY TRADES WILL PERSIST HERE THROUGH THE FORECAST PERIOD...WITH HIGHEST WINDS AND SEAS REMAINING NEAR THE COAST OF COLOMBIA. MEANWHILE...20 KT TRADE WINDS WILL OCCUPY MUCH OF THE TROPICAL N ATLC ZONE LATER TODAY THROUGH TUE BEFORE SHIFTING SOUTHWARD WED THROUGH FRI AS THE COLD FRONT CURRENTLY OVER THE GULF OF MEXICO MOVES EASTWARD NORTH OF THE AREA...SHOVING THE SUBTROPICAL RIDGE AND THE STRONGEST PRES GRADIENT SOUTHEASTWARD. SW N ATLC W OF 65W... THE PRES GRADIENT BETWEEN RIDGING FROM THE NE CORNER OF THE AREA NEAR 31N65W THROUGH THE NORTHERN BAHAMAS AND THE COLD FRONT THAT HAS PASSED OFF THE COAST OF S FL HAS BROUGHT SE TO S WINDS IN THE 20-30 KT RANGE TO WATERS W OF THE BAHAMAS N OF 24N THE PAST FEW HOURS ACCORDING TO MULTIPLE SHIP REPORTS. MANY THANKS TO THESE SHIPS FOR REPORTING TONIGHT. ONCE FACTORING FOR THE ANEMOMETER HEIGHTS ON MANY OF THESE SHIPS...WINDS AT 10 METERS ABOVE THE SEAS SURFACE IS LIKELY IN THE 20 TO 25 KT RANGE. IN ADDITION...THE 0154 UTC ASCAT PASS SHOWED A SOLID AREA OF 20 TO 25 KT WINDS...WITH A FEW EMBEDDED RETRIEVALS TO 30 KT...N OF THE BAHAMAS W OF 76W. THE GFS TRIES TO DEVELOP A LOW PRES WAVE ALONG THE BOUNDARY 28N75W THIS EVENING AND GENERATES GALE FORCE SOUTHERLY FLOW IN ITS SE QUADRANT. THIS APPEARS TO BE A CONVECTIVE FEEDBACK PROBLEM AS THE GFS ALSO DUMPS OVER 4 INCHES OF PRECIPITATION IN 6 HOURS NEAR THIS LOW. THE ECMWF CARRIES A MORE PROGRESSIVE WAVE ALONG THE COLD FRONT AND REFRAINS FROM GENERATING GALES UNTIL THE WAVE IS N OF THE FORECAST AREA. THIS SOLUTION IS MORE IN LINE WITH THE UKMET AND NOGAPS AS WELL. THE FORECAST FAVORS THE ECMWF THROUGH TUE AS A RESULT. HIGH PRES BUILDS BEHIND THE FRONT AND WINDS DIMINISH WED...BECOMING VARIABLE THU N OF 25N AS THE NW SWELL PUSHES E OUT OF THE AREA. SOUTHERLY WINDS WILL INCREASE ACROSS THE AREA FRI AS THE PRES GRADIENT BUILDS BETWEEN THE HIGH TO THE E AND THE SYSTEM TRAVERSING THE GULF OF MEXICO TO THE W. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER