000
AGXX40 KNHC 230613
MIMATS

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
215 AM EDT SUN MAR 23 2008

MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND 
SOUTHWEST NORTH ATLC S OF 31N W OF 55W.

CURRENTLY AN UPPER ANTICYCLONE IS NEAR 20N55W WITH A RIDGE 
EXTENDING WSW ACROSS THE CARIBBEAN TO NEAR NICARAGUA AND 
ACCOMPANIED BY DRY AIR ALOFT. AN UPPER TROUGH HAS MOVED E TO
ALONG 55W N OF 26N...WHILE A SECOND UPPER TROUGH HAS MOVED SE 
OVER THE CENTRAL GULF OF MEXICO. PLENTY UPPER DIFFLUENCE BETWEEN 
THE NW PERIPHERY OF THE RIDGE AND JUST AHEAD OF THE WESTERN 
TROUGH AND IS ENHANCING CONVECTION ALONG A FRONTAL WAVE LOW OVER 
W FLORIDA. THE SURFACE LOW IS EXPECTED TO CONTINUE ENE ACROSS 
FLORIDA DRAGGING THE REMNANTS OF A FRONTAL TROUGH N. THIS 
FRONTAL TROUGH CURRENTLY EXTENDS E FROM THE LOW ALONG 25N-26N TO 
WELL E OF 55W. 

AN ASSOCIATED SECONDARY COLD FRONT IS MOVING INTO THE NE GULF OF 
MEXICO AND IS EXPECTED TO MOVE SE AND MERGE WITH WHATEVER 
REMAINS OF THE FRONTAL TROUGH LATE TODAY WITH A SINGLE SURFACE 
FRONT LYING ALONG 31N74W 26N78W 17N88W LATE TONIGHT. APPEARS A 
THIRD COLD SURGE WILL PUSH INTO THE ATLC AREA LATE MON AND DRIVE 
THE FRONT E TO A LINE FROM 31N67W TO THE WINDWARD PASSAGE TO 
HONDURAS AROUND SUNRISE TUE...AND FROM 27N55W TO W HISPANIOLA TO 
NW COSTA RICA SUNRISE WED AND LOSING IDENTITY W OF 55W WED 
NIGHT.     
 
GULF OF MEXICO...BUOY AND SSMI DATA INDICATE WINDS NW SEMICIRCLE 
OF THE INLAND FRONTAL WAVE LOW PRES IN THE NE-E 15-20 KT RANGE 
WITH SEAS MAXING AT 5 FT. NE WINDS ALREADY INCREASING OVER THE W 
GULF TO 15-20 KT. EXPECT WINDS TO CONTINUE INCREASE TODAY 
THROUGH MON TO MOSTLY 25 KT BEHIND THE FAIRLY DRY COLD FRONT. BY 
TUE AFTERNOON GRADIENT RELAXING OVER W GULF AND SE RETURN FLOW 
SETS UP SPREADING E TO ALL WATERS WED NIGHT BUT WINDS CONTINUE 
IN 15-20 KT RANGE. MADE ADJUSTMENTS GFS WIND FIELD AND 
ASSOCIATED MAX SEAS OVER SW GULF FOR LATE TONIGHT INTO MON USING 
BLEND OF NAM AND GFS.

SW N ATLC...SW WINDS INCREASING 15-20 KT OVER WATERS N OF 30N IN 
RESPONSE TO APPROACHING SECONDARY FRONT. SE FLOW IN 15-20 KT 
RANGE E OF THE SE BAHAMAS. WINDS LIGHT AND VARIABLE CENTRAL 
PORTION ALONG FRONTAL TROUGH BUT CONVECTION HAS SPREAD E TO 
COVER WATERS N OF 25N W OF 74W. STILL EXPECTING WINDS BEHIND 
THIS NEW FRONT AT N-NE 10-15 KT WINDS THROUGH EARLY MON THEN A 
STRONG COLD SURGE WILL INCREASE WINDS TO NW-N 20-25 KT BEHIND 
THE FRONT AND INCREASE TO SW 20-25 KT N OF 28N E OF FRONT. 
MODELS STILL DIFFER SLIGHTLY ON POSSIBILITY OF GALE...BUT COLD 
AIR ADVECTION IMPRESSIVE SO I WILL GO WITH MINIMAL GALE N OF 30N 
WITHIN 300 NM W OF FRONT FROM SUNRISE TO SUNSET TUE. KICKED UP 
NWW3 SEAS ON GRAPHICS A COUPLE FT IN SAME AREA. ON WED NE WINDS 
20 KT S OF 27N WHILE WINDS DIMINISH TO LIGHT AND VARIABLE OVER 
THE NW WATERS. WINDS FURTHER DIMINISH TO 10-15 KT THROUGHOUT ON
THU BUT N SWELLS 8-10 FT E OF THE BAHAMAS.

CARIBBEAN AND TROPICAL N ATLC...NE TO E TRADES OVER THE E 
CARIBBEAN WILL CHANGE LITTLE. LIGHT NE-E WINDS OVER THE NW 
WATERS WILL INCREASE TO N-NE 20-25 KT BEHIND FRONT MON AND NOT 
LET OFF TILL WED. MAX SEAS ABOUT 11 FT IN YUCATAN CHANNEL 
SUNRISE TUE. BY THU MOSTLY E 15 KT WINDS THROUGHOUT EXCEPT 20-25 
KT ALONG COLUMBIAN COAST. N SWELLS 8-10 FT WILL MOVE INTO NW 
WATERS OF TROPICAL N ATLC ZONE EARLY THU SPREADING S TO ALONG 
16N SUNRISE FRI WITH N SWELLS ABOUT 8 FT IN NE CARIBBEAN 
PASSAGES.

WARNINGS...
ATLC...
GALE CONDITIONS EXPECTED TUE N OF 30N E OF 72W BEHIND FRONT. 

CARIBBEAN...
NONE.

GULF OF MEXICO...
NONE.

FORECASTER NELSON