000 AGXX40 KNHC 231849 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT FRI APR 23 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... A WEAK RIDGE OF HIGH PRES EXTENDING ACROSS FLORIDA FROM THE ATLC WILL CONTINUE TO WEAKEN AS THE HIGH SHIFTS MORE TO THE E. STRONG SOUTHERLY RETURN FLOW CONTINUES TO EXPAND EASTWARD ACROSS THE GULF AS INDICATED BY AN EARLIER WINDSAT SCATTEROMETER PASS WITH 20 KT ACROSS THE W AND CENTRAL GULF. A MORNING JASON ALTIMETER PASS ALSO CAPTURED 8-10 FT SEAS IN THE FAR W GULF WHERE THE SOUTHERLY FETCH IS THE LONGEST. A COLD FRONT CURRENTLY OVER CENTRAL TEXAS WILL MOVE TO THE SE THIS AFTERNOON AND EVENING PUSHING OFF THE TEXAS COAST AROUND SUNRISE SAT. LATEST SATELLITE IMAGERY AND RADAR MOSAICS INDICATE THAT THE MAJORITY OF THE CONVECTION ASSOCIATED WITH THIS FRONT IS WELL N OF 30N THUS ONLY EXPECT ISOLATED TSTMS TO OCCUR AS THE FRONT INITIALLY MOVES OFFSHORE WITH SOME ADDITIONAL ACTIVITY POTENTIALLY DEVELOPING THEREAFTER. THE FRONT WILL EXTEND FROM SW LOUISIANA TO JUST S OF TAMPICO MEXICO SAT AFTERNOON THEN FROM SE LOUISIANA TO THE CENTRAL BAY OF CAMPECHE SAT NIGHT. VARIOUS MODEL SOLUTIONS ARE IN AGREEMENT WITH REGARD TO SLOWING THE FRONT DOWN AS WELL AS WEAKENING IT CONSIDERABLY AS IT CONTINUES TO ADVANCE TO THE E-SE. THE FRONT WILL REACH FROM THE FLORIDA PANHANDLE TO THE NW YUCATAN PENINSULA SUN AFTERNOON AND FROM THE TAMPA BAY FLORIDA AREA TO CENTRAL YUCATAN BY EARLY MON...THEN FINALLY SE OF THE GULF WATERS BY LATE MON NIGHT. A WEAK TROUGH OF LOW PRES IS LIKELY TO DEVELOP IN THE SOUTHERN BAY OF CAMPECHE SUN NIGHT AS ENERGY ASSOCIATED WITH THE SOUTHERN/TAIL-END OF THE FRONT GETS LEFT BEHIND. MODELS LINGER THIS FEATURE IN THE SAME GENERAL AREA THROUGH MON NIGHT WITH HIGH PRES BUILDING DOWN FROM THE NW ON TUE. THE NEXT COLD FRONT WILL MOVE THROUGH THE SE UNITED STATES ON TUE AND IT APPEARS THAT IT WILL CLIP THE NE GULF REACHING FROM NEAR PANAMA CITY FLORIDA TO 26N88W EARLY TUE THEN FROM NEAR FORT MYERS FLORIDA TO THE YUCATAN CHANNEL TUE EVENING WITH REINFORCING HIGH PRES RETURNING BEHIND THE FRONT LATE TUE THROUGH WED. CARIBBEAN SEA AND TROPICAL N ATLC FROM 07N TO 22N W OF 55W... A TIGHT PRES GRADIENT EXISTS OVER THE CENTRAL AND W CARIBBEAN WITH A 1500 UTC ASCAT SCATTEROMETER PASS INDICATING NE-E WINDS OF 20-25 KT NEAR THE COAST OF COLOMBIA AND SE WINDS OF 20 KT IN THE GULF OF HONDURAS. A PAIR OF NDBC BUOYS BETWEEN THESE ASCAT SWATHES ARE ALSO REPORTING NE WINDS OF 20 KT. THIS GENERAL PATTERN WILL PERSIST INTO SAT NIGHT. THEREAFTER MODEL GUIDANCE SHIFTS THE SEMI-PERMANENT AREA OF LOW PRES OVER COLOMBIA INTO THE SW CARIBBEAN SEA WITH ITS REMNANTS DEGENERATING INTO A TROUGH WHILE LOW PRES REDEVELOPS OVER COLOMBIA ON MON. TRADES WILL DIMINISH SLIGHTLY ACROSS THE MAJORITY OF THE CARIBBEAN SUN NIGHT THROUGH EARLY WED AS THE PRES GRADIENT WEAKENS...WITH 20 KT TRADES PERSISTING MAINLY S OF 13N E OF 75W. OTHERWISE EXPECT NE SWELL OF UP TO 8 FT TO BLEED THROUGH THE NE ATLC PASSAGES MON THROUGH MON NIGHT. IN THE TROPICAL N ATLC...A SERIES OF WEAK FRONTAL TROUGHS WILL MOVE ACROSS THE NORTHERN PORTION OF THE BASIN THIS EVENING THROUGH THROUGH EARLY SUN WITH WINDS GENERALLY NE-E 10-15 KT ACROSS THE AREA. HIGH PRES BUILDS DOWN FROM THE NW-N LATER ON SUN AND TRADES WILL INCREASE TO 20 KT S OF 17N MON EVENING THROUGH WED AS THE PRES GRADIENT STRENGTHENS. IN ADDITION...LONG PERIOD NORTHERLY SWELL OF UP TO 11 FEET WILL PROPAGATE THROUGH THE AREA SUN NIGHT THROUGH EARLY NEXT WEEK...WHILE EASTERLY SWELL ALSO BUILDS MAINLY S OF 17N AS THE TRADEWIND FETCH LENGTH INCREASES. SW N ATLANTIC S OF 31N W OF 55W... A DEPARTING COLD FRONT CURRENTLY EXTENDS FROM NEAR 29N55W TO 25N62W WITH NW WINDS OF 20 KT CAPTURED BY A 1314 UTC ASCAT PASS N OF 29 AND W OF THE FRONT. THIS FRONT WILL MOVE E OF 55W LATER THIS EVENING. MEANWHILE 1019 MB HIGH PRES IS CENTERED NEAR 28N75W WITH GENERALLY LIGHT WINDS OCCURRING ACROSS THE W HALF OF THE AREA (EXCEPT FOR EASTERLY WINDS OF 10-15 KT W OF THE BAHAMAS). A REINFORCING COLD FRONT WILL DROP S OF 31N LATE TONIGHT INTO EARLY SAT STRETCHING FROM 31N55W TO 26N61W SAT MORNING. A SURGE OF 20-25 KT NW WINDS ARRIVE BEHIND THE FRONT WILL GUSTS OF 25-30 KT POSSIBLE N OF 29N NEAR 55W. LARGE NORTHERLY SWELL OF UP TO 20 FT WILL ALSO PROPAGATE S OF 30N AND E OF 60W. OTHERWISE HIGH PRES HOLDS IN PLACE OVER THE CENTRAL PORTION OF THE BASIN THROUGH SAT WITH SOUTHERLY RETURN FLOW INCREASING ALONG THE FLORIDA COAST SAT NIGHT THROUGH SUN EVENING. THE HIGH WILL SHIFT TO THE E AS THE NEXT COLD FRONT APPROACHES. THE FRONT WILL MOVE OFF OF N FLORIDA AROUND SUNRISE MON SLOWLY MOVING TO THE E AND EXTENDING FROM 31N76W TO NEAR CAPE CANAVERAL FLORIDA MON EVENING THEN FROM 31N72W TO THE STRAITS OF FLORIDA EARLY TUE THEN WILL WEAKEN AS IT CONTINUES TO THE E. YET ANOTHER (AND FASTER) COLD FRONT WILL MOVE OFF THE GEORGIA/N FLORIDA COAST TUE EVENING REACHING FROM NEAR 31N72W TO THE TURKS AND CAICOS BY EARLY WED. THE FRONT WILL CONTINUE TO ADVANCE TO THE E AND WILL EXTEND FROM 31N63W TO HISPANIOLA BY WED EVENING. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER LEWITSKY