000 AGXX40 KNHC 240723 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 230 AM EST TUE FEB 24 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO... CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. ATLC... THE PERSISTENT SUBTROPICAL RIDGE IS FORCING THE LONG-WAVE TROUGHS MOVING OFFSHORE NORTHEASTWARD OVER THE NW EDGE OF THE RIDGE. SOUTHERLY RETURN FLOW BETWEEN TROUGHING OVER THE SOUTHERN PLAINS AND RIDGING IN THE EASTERN GULF WILL KEEP WINDS AROUND 20 KT IN THE NW GULF FROM TUE NIGHT THROUGH THU. THE RIDGE AXIS SHOULD BECOME MORE EAST TO WEST ORIENTED OVER THIS TIME PERIOD. CONFIDENCE IN THE FORECAST DETAILS WANES BY THU/FRI AS THE FLOW BECOMES MORE ZONAL. THE GFS SOLUTION IS ON THE FASTER EDGE OF THE MODEL GUIDANCE CARRYING THE NEXT COLD FRONT INTO THE NW GULF ON FRI. HOWEVER...THE MODELS HAVE COME INTO BETTER AGREEMENT SINCE YESTERDAY...AND THE GFS IS ONLY APPROXIMATELY 3 HOURS FASTER THAN THE ECMWF. GIVEN THE AGREEMENT ON A PROGRESSIVE PATTERN...THINK THE FASTER GFS IS AN ACCEPTABLE FORECAST THROUGH FRI. CARIBBEAN... THE SUBTROPICAL HIGH IS MIGRATING EASTWARD AS THE DEEP LAYER TROUGH SUPPORTING THE COLD FRONT CURRENTLY MAKING ITS WAY THROUGH THE SW N ATLC INTO CENTRAL CUBA HAS ENCOUNTERED THIS RIDGE....WEAKENING THE PRESSURE GRADIENT BETWEEN IT AND THE LOW OVER COLOMBIA. IN ADDITION...THE COLOMBIAN LOW HAS WEAKENED TO 1010 MB THIS MORNING. THE ASCAT PASSES AROUND 0322 AND 0142 UTC SHOWED WINDS HAD SUBSIDED TO THE 20 TO 25 KT RANGE OR LOWER OVER MUCH OF THE CARIBBEAN S OF 18N E OF 80W. WINDS BEHIND THE COLD FRONT PASSING THROUGH CENTRAL CUBA ARE EXPECTED TO INCREASE AS THE NEW HIGH PRESSURE BEHIND THE COLD FRONT PASSES OFF THE EAST COAST TUE-THU. HOWEVER...AS THE FRONT EDGES EASTWARD...THE PRESSURE GRADIENT WILL RELAX SOMEWHAT OVER THE REST OF THE CARIBBEAN...AND WINDS SHOULD BEGIN TO DIMINISH GENERALLY TO AROUND 15 KT E OF 80W WED-SAT. ATLC... THE PERSISTENT SUBTROPICAL RIDGE IS FORCING THE LONG-WAVE TROUGHS MOVING OFFSHORE NORTHEASTWARD OVER THE NW EDGE OF THE RIDGE. THE PORTION OF THE FRONT S OF 26N CURRENTLY MOVING THROUGH THE SW N ATLC IS HAVING A HARD TIME MAKING IT E OF 65W. ACCORDING TO THE ASCAT PASS AT 0144 UTC...WINDS HAVE DIMINISHED BELOW 20 KT WITH THIS FRONT OVER FORECAST WATERS. THE FRONT WILL CONTINUE TO LOSE MUCH OF ITS PUNCH OVER FORECAST WATERS AS IT MOVES EASTWARD AND IS FORCED N OF THE SUBTROPICAL RIDGE. HOWEVER...THIS TROUGH WILL EAT INTO THE SURFACE RIDGING A BIT MORE THAN ITS PREDECESSOR...ALLOWING TRADES TO SUBSIDE SLIGHTLY OVER THE WESTERN PORTION OF THE ATLC S OF 20N TUE-THU. AT THIS TIME...TRADES ARE IN THE 20 TO 25 KT RANGE OVER NEARLY ALL OF THE FORECAST AREA S OF 20N. ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER SCHAUER CLARK. TROPICAL PREDICTION CENTER.