000 AGXX40 KNHC 161829 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 PM EDT SUN OCT 16 2011 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A STATIONARY FRONT EXTENDS FROM 20N82W TO 24N90W TO LOW PRES OVER THE EASTERN YUCATAN PENINSULA NEAR 19.5N88.0W 1004 MB DRIFTING NW. A TIGHT PRES GRADIENT REMAINS ACROSS THE GULF EXCEPT FOR THE FAR NW GULF...BETWEEN HIGH PRES OVER THE LOWER MISSISSIPPI VALLEY AND THIS LOW. A 1504 UTC HIGH RESOLUTION ASCAT SCATTEROMETER PASS SHOWED NE-E WINDS OF 20-30 KT WITH HIGHER GUSTS S OF 25N BETWEEN 85W AND 90W WHILE SEVERAL SHIP REPORTS EARLIER THIS MORNING INDICATED NEAR GALE TO GALE FORCE WINDS AND SEAS TO 13 FT. WILL MAINTAIN THE GALE WARNING FOR THIS AREA THROUGH TONIGHT. OTHERWISE...20-30 KT WINDS COVER THE MAJORITY OF THE REMAINDER OF THE GULF EXCEPT THE FAR NW GULF WHERE 10-15 KT EASTERLY WINDS ARE PRESENT. THE FRONT WILL LIFT BACK TO THE N AS A WARM FRONT TONIGHT INTO EARLY TUE STALLING FROM THE FLORIDA BIG BEND TO THE NW YUCATAN PENINSULA WHERE THE LOW WILL ATTEMPT TO EMERGE INTO THE FAR E BAY OF CAMPECHE TUE MORNING. THE 12 UTC UKMET...GFS...AND ECMWF EACH HAVE THE LOW IN DIFFERENT POSITIONS AT 24 AND 48 HOURS SO USED A BLEND OF THOSE SOLUTIONS FOR THE FORECAST POSITION. AS THIS OCCURS...THE PRES GRADIENT WILL WEAKEN ALLOWING FOR WINDS TO DIMINISH TO 10-20 KT AND FOR SEAS TO TEMPORARILY SUBSIDE. THIS LOW HAS A MEDIUM PROBABILITY OF TROPICAL CYCLONE FORMATION DURING THE NEXT 48 HOURS. REFER TO THE LATEST TROPICAL WEATHER OUTLOOK (MIATWOAT) FOR MORE DETAILS. A STRONG COLD FRONT WILL MOVE INTO THE FAR NW GULF EARLY TUE MORNING QUICKLY MOVING SE AND REACHING FROM SW FLORIDA TO THE YUCATAN PENINSULA BY EARLY WED...THEN MOVING SE OF THE YUCATAN CHANNEL LATE WED. STRONG NORTHERLY WINDS WILL ARRIVE BEHIND THE FRONT WITH GUSTS TO NEAR GALE FORCE POSSIBLE. THE GFS CONTINUES TO INDICATE THE POTENTIAL FOR GALE FORCE WINDS S OF 21N W OF 94W...ALTHOUGH THE LATEST SREF GUIDANCE ONLY INDICATES A 10-20 PERCENT PROBABILITY OF GALE OR HIGHER WINDS...WHILE THE GEFS ENSEMBLE PROBABILITIES REMAIN AT 0 PERCENT...SO WILL REFRAIN FROM GALE CONDITIONS EXPECTED WORDING FOR NOW ALTHOUGH GIVEN THE DEPTH OF THE COLD AIR MASS FOLLOWING THE FRONT AND THE WARM WATERS OF THE GULF WILL NEED TO CONTINUE TO MONITOR IN CASE GALES BECOME MORE LIKELY. HIGH PRES BUILDS IN BEHIND THE FRONT LATE WED THROUGH THU WITH WINDS GRADUALLY DIMINISHING FROM NW TO SE...DOWN TO 10-15 KT BY LATE WED AS THE AIRMASS QUICKLY MODIFIES AND AS THE HIGH SINKS BACK DOWN OVER THE LOWER MISSISSIPPI VALLEY. CARIBBEAN SEA AND TROPICAL N ATLC... AS MENTIONED IN THE SECTION ABOVE...1004 MB LOW PRES IS OVER THE EASTERN YUCATAN PENINSULA NEAR 19.5N88.0W AND IS DRIFTING NW. A 1504 UTC HIGH RESOLUTION ASCAT SCATTEROMETER PASS SHOWED NE-E 20-30 KT WINDS WITH HIGHER GUSTS N OF THE MONSOON TROUGH WHICH EXTENDS FROM THE LOW TO NEAR 20N82W. A FEW GUSTS TO GALE FORCE WILL BE POSSIBLE IN THE SCATTERED TO NUMEROUS CONVECTION OCCURRING OVER THIS AREA...ALTHOUGH WILL REFRAIN FROM A GALE WARNING AT THIS TIME GIVEN THE SHORT-FUSED NATURE OF CONVECTIVE GUSTS. MAINLY 10-15 KT WINDS COVER THE REMAINDER OF THE CARIBBEAN BASIN UNDER A BROAD AND WEAK PRES PATTERN. THE LOW WILL CONTINUE NW AND WINDS WILL BECOME SOUTHERLY TONIGHT THROUGH TUE WITH 15-20 KT POSSIBLE IN THE NW CARIBBEAN SEA AHEAD OF THE FIRST STRONG COLD FRONT OF THE SEASON. THE FRONT WILL PUSH SE OF THE YUCATAN CHANNEL EARLY WED REACHING FROM WESTERN CUBA TO THE GULF OF HONDURAS WED EVENING...THEN FROM CENTRAL CUBA TO NE NICARAGUA BY THU EVENING. A SURGE OF NORTHERLY 20-25 KT WINDS ARE EXPECTED BEHIND THE FRONT WITH GUSTS TO 30 KT POSSIBLE IN AND NEAR THE YUCATAN CHANNEL. OTHERWISE...A WEAKENING TROPICAL WAVE IS IN THE TROPICAL N ATLC WATERS S OF 17N APPROACHING 60W WITH SCATTERED SHOWERS AND TSTMS OCCURRING NEAR THE CENTRAL PORTION OF THE WAVE AXIS. THIS WAVE WILL ENTER THE FAR E CARIBBEAN TONIGHT...THEN WILL DAMPEN AND DISSIPATE OVER THE E CARIBBEAN MON NIGHT INTO TUE. NE-E 15-20 WINDS AND SEAS TO 8 FT WILL BE POSSIBLE FROM 12N-16N UNTIL MON. ANOTHER TROPICAL WAVE WILL APPROACH THE TROPICAL N ATLC THU...APPROACHING THE LESSER ANTILLES EARLY FRI. SW N ATLC S OF 31N W OF 55W... A STATIONARY FRONT REACHES FROM NEAR BERMUDA TO ACROSS THE NORTHERN BAHAMAS TO S FLORIDA WITH AREAS OF RAIN IN THE VICINITY OF THE FRONT. RECENT WINDSAT AND ASCAT SCATTEROMETER PASSES INDICATED MAINLY 10-15 KT NE-E WINDS ACROSS THE SW N ATLC... ALTHOUGH THESE PASSES MISSED THE AREA S OF 27N W OF 75W WHERE MODEL GUIDANCE CONTINUES TO SHOW EASTERLY WINDS OF 20-25 KT THROUGH THE NEXT 12-24 HOURS...DIMINISHING TO 20 KT BY 24-36 HOURS AS THE PRES GRADIENT OVER THE AREA WEAKENS. HIGH PRES BRIEFLY BUILDS IN ALONG 30N/31N MON...THEN RETREATS NE TUE. SOUTHERLY FLOW WILL INCREASE TO 15-20 KT AHEAD OF A COLD FRONT TUE. THE OPERATIONAL 12 UTC GFS MODEL CONTINUES TO SHOW AN AREA OF GALE FORCE WINDS N OF 28N AHEAD OF THE FRONT WITH GEFS ENSEMBLE 34 KT WIND PROBABILITIES UP TO 70-80 PERCENT AND THE RECENT SREF PROBABILITIES UP TO 40 PERCENT ALONG 31N FOR TUE NIGHT THROUGH WED MORNING. IF THIS TREND CONTINUES WILL NEED TO INCLUDE GALE CONDITIONS EXPECTED WORDING OVER THE N WATERS AHEAD OF THE FRONT. THE FRONT WILL REACH FROM NEAR 31N79W TO DAYTONA BEACH FLORIDA WED MORNING...FROM 31N72W TO CENTRAL CUBA THU MORNING...THEN FROM JUST W OF BERMUDA TO THE TURKS AND CAICOS EARLY FRI WHERE IT WILL STALL AND WEAKEN. W-NW 20-25 KT WINDS ARRIVE BEHIND THE FRONT EARLY WED THROUGH EARLY TUE...QUICKLY DIMINISHING TO 10-15 KT LATE THU THROUGH FRI AS HIGH PRES BUILDS IN FROM THE W-NW AND AS THE FRONT CONTINUES TO WEAKEN. WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER LEWITSKY