000 AGXX40 KNHC 181812 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 115 PM EST SAT MAR 18 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A WEAK FRONTAL BOUNDARY CURRENTLY FROM CENTRAL FLORIDA TO SE TEXAS WILL BECOME DIFFUSE TONIGHT AS IT SAGS SWD THEN DISSIPATES SUN. SLY FLOW WILL CONTINUE TO INCREASE OVER THE W GULF TONIGHT AND SUN REACHING 20 TO 25 KT SUN NIGHT. STRONG SLY WINDS THEN EXPAND EWD OVER THE REMAINDER OF THE GULF WATERS SUN NIGHT AND MON AHEAD OF THE NEXT COLD FRONT WHICH MOVES OFF THE TEXAS COAST MIDDAY MON EXTENDING FROM S FLORIDA TO THE E BAY OF CAMPECHE WED. HIGHEST WINDS EXPECTED E OF THE FRONT WITH A LARGE SWATH OF 20-25 KT COVERING MOST OF THE GULF MON THEN DECREASING LATE MON THROUGH WED AS THE SUBTROPICAL RIDGE RETREATS E OF AREA AND THE PRES GRADIENT RELAXES. INITIALLY...WINDS BEHIND THE FRONT WILL BE IN THE 15-20 KT RANGE BUT MAY INCREASE TO 20-25 KT IN NELY FLOW ON WED AS RIDGING BUILDS IN FROM THE N. THEREAFTER...THE FORECAST GETS A LITTLE TRICKY AS MOST OF THE GLOBAL MODELS SHOW THE FRONT SLOWING UP OR BECOMING STATIONARY OVER THE SE GULF ON WED AND THEN POSSIBLY RETURNING NWD THU. WHILE GENERALLY AGREEING IN THIS OVERALL FORECAST EVOLUTION...THE DEVIL IS IN THE DETAILS. GIVEN THE UNCERTAINTY...WILL USE THE GFS ENSEMBLE MEAN FOR GENERAL GUIDANCE ON LOCATION OF STATIONARY FRONT AND BROAD BRUSH CONDITIONS N/S OF BOUNDARY. SW N ATLANTIC... A WEAK FRONT AND ATTENDANT PRE-FRONTAL TROUGH CONTINUE TO BE THE MAIN WEATHER MAKERS OVER THE ATLC WATERS. HOWEVER...A COMPLEX STRUCTURE EXISTS IN ASSOCIATION WITH THESE TWO FEATURES THUS MAKING THE WIND FIELD COMPLEX AND DIFFICULT TO ASSESS. ESSENTIALLY...THE WINDS INCREASE...DECREASE...INCREASE...E/W ACROSS THE FRONT AND TROUGH. WHILE SOMEWHAT OVERSIMPLIFIED...CONDENSED THE FIRST FEW PERIODS A BIT TO BROAD BRUSH CONDITIONS. AT ANY RATE...STRONGEST WINDS AND HIGHEST SEAS ARE CURRENTLY LOCATED N OF 27N E OF 70W AND EXPECTED TO REMAIN THERE THROUGH MON. THEREAFTER...FOCUS SHIFTS WEST AS SLY FLOW BEGINS TO INCREASE AHEAD OF NEXT COLD FRONT CURRENTLY ANTICIPATED TO MOVE OFF THE SE U.S. COAST LATE TUE. AS HAS BEEN THE CASE MUCH OF THE WINTER...STRONGEST WINDS EXPECTED IN ADVANCE OF THE FRONT. GFS FAIRLY CONSISTENT WITH 20-30 KT GENERALLY N OF 25N OR 26N. THE GFS IS ALSO STILL SHOWING MARGINAL GALE CONDITIONS RIGHT ALONG THE N BOUNDARY BUT I'M NOT YET CONVINCED SO HOLDING OFF ON HEADLINES FOR NOW. POST-FRONTAL NLY FLOW STILL EXPECTED IN THE 20-25 KT RANGE. SUBTROPICAL RIDGE WILL GET PUSHED OVER THE FAR S WATERS TUE THROUGH THU. THIS COMBINED WITH BLOCKING/SHELTERING EFFECT FROM THE BAHAMAS WILL YIELD LOWEST SEAS OVER THE SW PART OF AREA. CARIBBEAN AND TROPICAL N ATLC... LITTLE CHANGES SEEN IN TRADES ACROSS MUCH OF THE CARIBBEAN WITH HIGHEST WINDS/SEAS REMAINING OVER THE SW CARIBBEAN NEAR THE COAST OF COLOMBIA AND LOWEST WINDS/SEAS OVER THE NW CARIBBEAN NEAR THE COAST OF CUBA. EXPECT SOME DIURNAL FLUCTUATIONS OF THE WINDS NEAR COLOMBIA DURING THE FORECAST PERIOD...BUT OVERALL CONDITIONS LOOK TO REMAIN IN THE 20-30 KT RANGE WITH SEAS RANGING FROM 8-12 FT. WINDS/SEAS PEAK SUN NIGHT INTO MON AS A MIGRATORY HIGH MOVES SEWD OVER THE W ATLC. OVER THE W CARIBBEAN...GENERALLY LIGHT TO MODERATE WINDS WILL CONTINUE THROUGH SUN...THEN BEGIN INCREASING AGAIN SUN NIGHT AND MON AS THE ATLC RIDGE STRENGTHENS. PRES GRADIENT AND ASSOCIATED WINDS THEN EXPECTED TO RELAX LATE TUE THROUGH THU AS A FRONTAL SYSTEM OVER THE GULF APPROACHES THE AREA POSSIBLY BECOMING STATIONARY OVER OR JUST N OF THE FAR NW PART. AS SUCH...MUCH UNCERTAINTY EXISTS FOR THE NW CARIBBEAN ZONE BY MID-WEEK. FOR THE TROPICAL N ATLC...MODERATE TRADES AND SWELLS TO 8 FT EXPECTED GENERALLY S OF 17N. RIDGE OVER FAR N PART WILL KEEP WINDS BELOW NORMAL BUT NLY SWELL WILL AFFECT THE AREA THROUGH THE FORECAST. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RHOME