000 AGXX40 KNHC 231855 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 230 PM EST MON FEB 23 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO... CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A COLD FRONT EXTENDS FROM S FLORIDA TO THE YUCATAN PENINSULA AND IS ABOUT TO EXIT THE GULF OF MEXICO. WINDS BEHIND THE FRONT ARE NOW NORTHEASTERLY 15 TO 20 KT WITH SEAS PREDOMINATELY 5-8 FT WITH THE HIGHEST SEAS IN THE BAY OF CAMPECHE. GUIDANCE AGREES ON BRINGING THE WINDS DOWN GRADUALLY UNDER AN INCREASINGLY MORE ZONAL MID LATITUDE PATTERN. NORTHERLY FLOW IN THE 20-25 KT WILL FUNNEL THROUGH THE YUCATAN CHANNEL TONIGHT BEHIND THE FRONT AS A SURFACE RIDGE AXIS SLOWLY MAKES ITS WAY EASTWARD ACROSS THE CENTRAL GULF AND INTO THE EASTERN GULF OF MEXICO THROUGH WED. BY THU/FRI...THE RIDGE AXIS SHOULD BE MORE LATITUDINAL...CENTERED NEAR 29N. SOUTHERLY RETURN FLOW BETWEEN TROUGHING OVER THE SOUTHERN PLAINS AND RIDGING IN THE EASTERN GULF WILL KEEP WINDS AROUND 20 KT. CONFIDENCE IN THE FORECAST DETAILS WANES BY WED/THU AS THE FLOW BECOMES MORE ZONAL. WHILE TROUGHING IS EXPECTED TO LINGER OVER THE SOUTHERN PLAINS TUE-FRI...NO COLD FRONT WILL MAKE IT INTO THE GULF. CARIBBEAN... THE PRESSURE GRADIENT BETWEEN THE LOW PRESSURE OVER COLOMBIA AND THE SUBTROPICAL RIDGE N OF THE CARIBBEAN HAVE BROUGHT WINDS TO THE 20-30 KT RANGE ACROSS MUCH OF THE CARIBBEAN S OF 18N E OF 83W. HOWEVER...THE SUBTROPICAL HIGH HAS BEGUN ITS EASTWARD MIGRATION AS THE DEEP LAYER TROUGH SUPPORTING THE COLD FRONT CURRENTLY MAKING ITS WAY THROUGH THE GULF HAS ENCOUNTERED THIS RIDGE....WEAKENING THE PRESSURE GRADIENT. IN ADDITION...THE LOW OVER COLOMBIA HAS WEAKENED TO 1010 MB. WINDS WILL PICK UP OVER THE NW CARIBBEAN INCLUDING THE YUCATAN CHANNEL TONIGHT. THE PRESSURE GRADIENT WILL REMAIN STRONG OVER THE NW CARIBBEAN AS NEW HIGH PRESSURE BEHIND THE COLD FRONT CURRENTLY IN THE GULF 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 TUE-FRI. ATLC... THE PERSISTENT SUBTROPICAL RIDGE IS FORCING THE LONG-WAVE TROUGHS MOVING OFFSHORE NORTHEASTWARD OVER THE NW EDGE OF THE RIDGE. THE TROUGH CURRENTLY MOVING INTO NW WATERS IS EXPECTED TO MERGE WITH THE LINGERING BOUNDARY STRETCHED ACROSS THE SW N ATLC ZONE INTO THE CENTRAL BAHAMAS. AT THE SURFACE...FRONTS S OF 25N ARE HAVING A HARD TIME MAKING IT E OF 65W. WINDS NORTH OF THE NEW COLD FRONT CURRENTLY PASSING OFF THE N FL COAST ARE IN THE 20-25 KT RANGE WHILE WINDS NEAR THE LEAD BOUNDARY ARE CONSIDERABLY LIGHTER. THE NEW FRONT WILL ALSO 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 20-30 KT RANGE OVER NEARLY ALL OF THE FORECAST AREA S OF 20N. ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER FORMOSA. TROPICAL PREDICTION CENTER.