000 AGXX40 KNHC 220537 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 145 AM EDT FRI MAR 21 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. UPPER LEVELS...AN UPPER ANTICYCLONE IS NEAR 15N80W WITH A RIDGE EXTENDING E THROUGH ANOTHER ANTICYCLONE AT 23N55W WITH THE RIDGE CONTINUING E TO A SHARP CREST NEAR 28N47W BUT COLLAPSING SE WITH TIME. AN INITIAL UPPER TROUGH HAS MOVED S STALLING ALONG THE N PERIPHERY OF THIS RIDGE RESULTING IN ZONAL UPPER FLOW OVER THE SUBTROPICAL PORTION DISCUSSION AREA. THE NEXT SHORTWAVE IS NOTED OVER THE MS VALLEY ATTM...AND IS EXPECTED TO CONTINUE SE INTO THE NORTHERN GULF OF MEXICO SUN...AND OFF THE SE COAST CONUS U.S. EARLY SUN NIGHT. LOW LEVELS...A COLD FRONT EXTENDS FROM 31N55W TO 27N65W WHERE IT STALLS AND EXTENDS W TO A LOW PRES OVER THE SE GULF OF MEXICO. STILL EXPECTING THE SURFACE LOW TO DRIFT N DRAGGING THE FRONTAL REMNANTS N AS A WEAK WARM FRONT OVER THE NW BAHAMAS AND STRAITS OF FL TODAY. MODELS NOT AS AGGRESSIVE WITH THE LOW PRES IN THE LATEST RUNS...BUT WE MAY STILL SEE A WEAK CYCLONIC FEATURE MOVING E ALONG THE FRONTAL TROUGH LATE TODAY AND TONIGHT. A SECONDARY COLD FRONT WILL MOVE INTO THE AREA FROM 31N79W ACROSS N FL AND THE NORTHERN GULF OF MEXICO TONIGHT AND MERGE WITH WHATEVER REMAINS OF THE INITIAL BOUNDARY ON SUN. THIS SECOND COLD SURGE IS A LOT STRONGER AND IT WILL MOVE SE TO LINE FROM BERMUDA TO NW CUBA TO BELIZE SUNRISE MON...AND FROM JUST S OF BERMUDA TO THE WINDWARD PASSAGE TO NICARAGUA SUNRISE TUE. THE FRONT WILL GET A THIRD COLD SURGE OVER THE ATLC PORTION TUE AND WED WITH MODELS HINTING AT NEAR GALE NW WINDS ALONG 30N E OF 70W LATE TUE INTO WED. GULF OF MEXICO...BUOY AND LAST QSCAT PASS INDICATE WINDS N SEMICIRCLE OF THE BROAD LOW PRES IN THE NE-E 15-20 KT RANGE WITH SEAS MAXING AT 5 FT. WILL GO WITH THIS STRENGTH OVER E CENTRAL WATERS TODAY INTO TONIGHT. BY THEN SECOND DRY FRONT MOVES INTO NORTHERN WATERS WITH WINDS INCREASING TO NE 15-20 KT ALL WATERS BEHIND FRONT TONIGHT AND SUN AND THEN FURTHER INCREASING TO 20 TO 25 KT OVER THE NE WATERS LATE SUN NIGHT. THIS NE 25 KT COLD SURGE WILL SPREAD S MON AND MON NIGHT OVER WATERS E OF 90W WITH WINDS DIMINISHING TO E AT 15 KT TUE OVER ENTIRE GULF...BECOMING SE OVER THE NW WATERS TUE NIGHT AND WED. SW N ATLC...A BAND OF NE 15-20 KT WINDS ARE OBSERVED N OF THE FRONTAL REMNANTS ATTM BUT ARE EXPECTED TO DIMINISH SOME THIS MORNING AS THE BOUNDARY DRIFTS N. THE NEXT DRY FRONT WILL ONLY BE ACCOMPANIED BY N 10-15 KT WINDS THROUGH SUN NIGHT. BUT ON MON THE NORTHERLY FLOW WILL INCREASE TO 20-25 KT OVER THE NW WATERS AND THEN SPREAD E THROUGH MON NIGHT TO INCLUDE ALL WATERS W OF THE FRONT WITH THE STRONGEST WINDS AT 25-30 KT N OF 28N E OF 72W. ON WED NE WINDS 20 KT S OF 27N WHILE WINDS DIMINISH TO LIGHT AND VARIABLE OVER THE NW WATERS. CARIBBEAN AND TROPICAL N ATLC...NE TO E TRADES OVER THE CENTRAL CARIBBEAN WILL GRADUALLY DIMINISH THIS WEEKEND. LARGE LONG PERIOD N SWELL STILL PROPAGATING THROUGH EXPOSED ATLC PASSAGES NE CARIBBEAN. THE LARGEST SWELL WILL PASS SE OF TROPICAL ATLC ZONE SAT WITH SEAS BELOW 10 FT ALL AREAS LATE SUN NIGHT. NE TO E TRADES AT 15 TO 20 KT ALL WATERS MON NIGHT AND TUE INCREASING TO 20 KT TUE NIGHT AND WED. HIGHER WINDS AND SEAS CONTINUE ALONG COLUMBIAN COAST. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER NELSON