000
AGXX40 KNHC 120720
MIMATS

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
230 AM EST TUE JAN 12 2010

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

GULF OF MEXICO...
1031 MB HIGH LOCATED OVER SE LOUISIANA EXTENDS A RIDGE OVER THE 
ENTIRE GULF REGION PRODUCING MODERATE BREEZE AND SEAS GENERALLY 
UNDER 5 FT WITH THE EXCEPTION OF THE SW PORTION OF THE GULF AND 
NEAR THE YUCATAN CHANNEL WHERE WINDS OF 15 TO 20 KT ARE STILL 
NOTED RAISING SEAS TO AROUND 6 FT. WINDS WILL GRADUALLY VEER NE 
TO E WED. A COASTAL TROUGH IS EXPECTED TO DEVELOP IN THE FAR SW 
GULF TONIGHT THROUGH WED. SOUTHERLY RETURN FLOW WILL INCREASE TO 
20 TO 30 KT OVER THE WESTERN GULF THU AHEAD OF THE NEXT COLD 
FRONT WHICH IS FORECAST TO MOVE OFF THE COAST OF TEXAS THU NIGHT 
INTO EARLY FRI. GLOBAL MODELS ARE FORECASTING A DEEPENING LOW TO 
DEVELOP ALONG THIS FRONT ACROSS THE NW GULF FRI AND PRODUCE GALE 
FORCE WINDS IN THE SW FLOW JUST AHEAD OF THE LOW...AND ALSO IN 
THE NW-WLY FLOW BEHIND IT. THE GFS MODEL MOVES THE LOW PRES EWD 
ACROSS THE NORTHERN GULF WATERS. SEAS ARE EXPECTED TO REACH 
AROUND 14 FT WITH THIS DEVELOPING SYSTEM.

CARIBBEAN AND TROPICAL N ATLC W OF 55W...
STRONG PRES GRADIENT AND UNUSUALLY STRONG COLD AIR ADVECTION 
CONTINUE TO AFFECT THE WESTERN CARIBBEAN BEHIND A DISSIPATING 
FRONTAL ZONE THAT CURRENTLY EXTENDS FROM THE MONA PASSAGE TO THE 
COSTA RICA/PANAMA BORDER. FRESH TO STRONG NLY WINDS ARE STILL 
BLOWING BEHIND THIS FRONT DOMINATING THE AREA BETWEEN 75W AND 
85W PER A RECENT ASCAT PASS. THESE WINDS OF 20-30 KT WINDS  
HAVE PRODUCED A LARGE AREA OF SEAS 12 FT OR GREATER ACROSS A 
LARGE PORTION OF THE WESTERN CARIBBEAN WITH THE HIGHEST SEAS 
PRESENTLY JUST OFF SHORE THE CARIBBEAN COAST OF NICARAGUA. THE 
FRONT IS FORECAST TO DISSIPATE LATE TODAY BUT A FRONTAL TROUGH 
WILL REMAIN FOR ABOUT 24 HOURS. FRESH NELY WINDS WILL PERSIST NW 
OF THE FRONTAL TROUGH THROUGH WED...THEN WILL DIMINISH THU WITH 
EASTERLY TRADES INCREASING ACROSS THE S AND CENTRAL CARIBBEAN AS 
HIGH PRES BUILDS N OF AREA.

MODERATE TRADES CAN BE FOUND ACROSS THE TROPICAL ATLC E OF THE 
LESSER ANTILLES WHERE THE ATLC RIDGE IS WEAKENING AHEAD OF THE 
APPROACHING COLD FRONT IN THE SW N ATLC. A MIX OF NW...NE...AND 
ELY TRADE WIND SWELL WILL DOMINATE SEAS THERE FOR THE NEXT FEW 
DAYS.  

SW N ATLC S OF 31N W OF 55W...
A DISSIPATING FRONTAL ZONE IS OVER THE FAR SE PORTION OF THE 
DISCUSSION AREA. THE FRONT WILL MOVE E-SE THROUGH THIS EVENING 
WHILE GRADUALLY WEAKENING. NLY WINDS OF 20 KT ARE SEEN BEHIND 
THIS FRONTAL BOUNDARY PARTICULARLY S OF 23N AND E OF 73W PER AN 
ASCAT PASS FROM AROUND 0220 UTC. HIGH PRES WILL BUILD IN BEHIND 
THE FRONT INTO EARLY WED...WITH ANOTHER COLD FRONT CLIPPING THE 
N PORTION OF THE FORECAST AREA LATE TODAY THROUGH WED...MOVING E 
OF 65W BY WED NIGHT. WINDS WILL INCREASE TO 20-25 KT AHEAD AND 
BEHIND OF THIS SECOND COLD FRONT AFFECTING THE AREA MAINLY N OF 
28N. LONG PERIOD N SWELL WITH SIGNIFICANT WAVE HEIGHTS AS HIGH 
AS 14 FT HAVE MOVE INTO THE WATERS E OF THE BAHAMAS. A NEW BATCH 
OF NW SWELL IS EXPECTED BEHIND THE SECOND COLD FRONT RAISING 
SEAS TO 13 FT. HIGH PRES WILL REBUILD ACROSS THE WATERS WED 
THROUGH FRI...WITH RETURN SOUTHERLY FLOW INCREASING NEAR THE 
FLORIDA COAST LATE FRI THROUGH SAT WITH THE POTENTIAL OF GALE 
FORCE WINDS LATE SAT INTO SUN.   

WARNINGS...
ATLC...
.NONE.

CARIBBEAN...
.NONE. 

GULF OF MEXICO...
.NONE.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
FORECASTER GR