000 AGXX40 KNHC 011906 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 215 PM EST TUE DEC 01 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... BUOYS 42363 AND 42001 HAVE SHOWN WINDS IN THE 25 TO 30 KT RANGE FOR SEVERAL HOURS THIS AFTERNOON WHILE OBSERVATIONS FROM SHIP DARU AND MOBILE RIG V7MO2 HAVE FLIRTED WITH GALES...GENERALLY WITHIN THE SHOWERS AND THUNDERSTORMS NEAR THE SURFACE LOW. THE 1005 MB LOW WAS NEAR 26N96W AT 1200 UTC AND IS FORECAST TO DEEPEN AS IT MOVES NE TONIGHT...WITH GALE FORCE WINDS SCHEDULED TO BEGIN THIS AFTERNOON WITHIN 180 NM SE SEMICIRCLE OF THE LOW. THE GFS AGAIN APPEARS TO HAVE FEEDBACK ISSUES WITH THE SHORTWAVE ENERGY AHEAD OF THE UPPER LOW OVERNIGHT TONIGHT THAT CAUSE IT TO ROCKET THE SURFACE LOW E OF THE OTHER MODELS AS IT MOVES ONSHORE. THE ECMWF NO LONGER CARRIES 35 KT WINDS IN THE GULF AHEAD OF THE SYSTEM...BUT ITS INITIALIZATION APPEARS TOO LIGHT WITH THE WINDS NEAR THE LOW CENTER. THE 1200 UTC GEFS PROBABILITIES OF GALE FORCE WINDS SHOW NO SUPPORT FOR A GALE...AND THE 0900 UTC SREFS SHOW LESS THAN A 20 PERCENT CHANCE OF GALES. WITH THE MODELS AGREEING ON AN INCREASINGLY MORE AMPLIFIED NORTHERN STREAM SURFACE PATTERN WITH A BUILDING HIGH PRES SYSTEM OVER THE CENTRAL N ATLC TUE-THU...BELIEVE THE GRADIENT WILL BE STRONG ENOUGH TO SUPPORT THE GALES. OVERALL...ADJUSTMENTS WERE MADE TOWARD A SLOWER SOLUTION WITH THE COLD FRONT AND SURFACE LOW THAN THE GFS BUT A STRONGER SOLUTION THAN THE ECMWF. THERE IS EVEN MORE UNCERTAINTY IN FORECAST OVER THE WEEKEND WHEN A SECONDARY COLD SURGE IS EXPECTED....BUT THE GFS SHOWS A STRONGER SURGE THAN MOST OF THE OTHER MODELS SO THE FORECAST CALLS FOR A WEAKER SOLUTION THAN THE GFS. CARIBBEAN AND TROPICAL N ATLC... SURFACE OBSERVATIONS SHOW THAT THE WINDS HAVE SHIFTED MORE SOUTHERLY IN THE NW CARIBBEAN IN ADVANCE OF THE STRONG COLD FRONT IN THE GULF OF MEXICO. THIS FRONT IS EXPECTED TO PUSH THROUGH THE YUCATAN CHANNEL ON THU AND BRING 20 TO 25 KT NE FLOW BEHIND IT BY FRI. FARTHER SOUTH...THE PRES GRADIENT N OF THE COLOMBIAN LOW IS RELATIVELY WEAK DUE TO THE WEAK FRONTAL BOUNDARY STRETCHED OVER THE SOUTHERN SW N ATLC ZONE. THE ASCAT PASS FROM 1418 UTC SHOWS 20 TO 25 KT WINDS IN THE CENTRAL CARIBBEAN PRIMARILY NEAR THE COAST OF COLOMBIA. BY MID WEEK...A MORE AMPLIFIED NORTHERN STREAM PATTERN WITH BUILDING HIGH PRES OVER THE CENTRAL N ATLC SHOULD STRENGTHEN THE PRES GRADIENT OVER THE EASTERN CARIBBEAN AND TROPICAL N ATLC...WITH TRADES BUMPING UP IN THESE REGIONS ABOVE 20 KT. SW N ATLC... THE 1416 UTC ASCAT PASS SHOWS WINDS NORTHERLY WINDS PICKING UP TO 15 TO 20 KT OVER NW WATERS BEHIND THE COLD FRONT OVER NW WATERS. THE MODELS ARE IN REASONABLE GOOD AGREEMENT WITH THE FORECAST OF THIS FRONT. THIS BOUNDARY RETREATS NORTH AS A WARM FRONT OVERNIGHT TUE NIGHT AND SOUTHERLY FLOW INCREASES AHEAD OF THE STRONG COLD FRONT IN THE GULF OF MEXICO. SEE THE GULF OF MEXICO SECTION FOR FORECAST THINKING WHICH FAVORS A SLOWER SOLUTION THAN THE GFS. THE 1200 UTC GEFS AND 0900 UTC SREF SHOW LITTLE SUPPORT FOR GALES IN THE SW N ATLC ZONE IN THE SOUTHERLY FLOW AHEAD OF THE FRONT. THE MODELS ARE TRENDING TOWARD TURNING THE SYSTEM NEGATIVE TILT FARTHER NORTH AND RETREATING THE WINDS FARTHER NORTH AS A RESULT. CONFIDENCE IS LOW...BUT GIVEN THE DETERMINISTIC MODEL SUPPORT...GALES CONTINUE TO BE FORECAST. WARNINGS... ATLC... AMZ088...GALE CONDITIONS EXPECTED E OF FRONT LATE WED INTO EARLY THU N OF 29N W OF 70W... CARIBBEAN... .NONE. GULF OF MEXICO... GMZ080 AND GMZ084 AND GMZ086...GALE WARNING N OF 27N E OF 92W... $$ FORECASTER SCHAUER