000 AGXX40 KNHC 170729 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 AM EDT MON OCT 17 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...1003 MB LOW PRES IS JUST NE OF THE YUCATAN PENINSULA NEAR 22N86.5W DRIFTING NNW. SATELLITE IMAGERY SHOWS NUMEROUS STRONG CONVECTION COVERING THE FAR NW CARIBBEAN SEA AND YUCATAN CHANNEL. THE REMAINDER OF THE CARIBBEAN SEAS HAS MAINLY E WINDS OF 10-15 KT WINDS UNDER A BROAD AND WEAK PRES PATTERN. AS THE LOW MOVES FURTHER AWAY FROM THE CARIBBEAN ...THE WINDS IN THE NW CARIBBEAN WILL DIMINISH TO AROUND 20 KT WHILE CHANGING TO A MORE S-SW BY WED IN RESPONSE TO THE FIRST STRONG COLD FRONT OF THE SEASON TO MOVE INTO THE AREA. 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. THE FRONT WILL BECOME STATIONARY FRI WHILE WEAKENING FROM EASTERN CUBA TO NE NICARAGUA. 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 THAT ENTERED THE FAR EASTERN CARIBBEAN SEA IS ALONG 62W/63W S OF 17N. SCATTERED SHOWERS AND TSTMS ARE NOTED S OF 14N AND E OF THE WAVE AXIS. THE WAVE WILL DAMPEN AND DISSIPATE OVER THE E CARIBBEAN TONIGHT THROUGH TUE NIGHT. NE-E 15-20 WINDS AND SEAS TO 8 FT SHOULD CONTINUE THROUGH TUE NIGHT. ANOTHER TROPICAL WAVE WILL APPROACH THE TROPICAL N ATLC THU...AND THE LESSER ANTILLES EARLY FRI. SW N ATLC S OF 31N W OF 55W... THE PRELIMINARY 0600 UTC SURFACE ANALYSIS SHOWS A STATIONARY FRONT EXTENDING FROM 31N66W TO THE NORTHERN BAHAMAS AND TO WEST PALM BEACH FLORIDA WHILE A WEAK HIGH CENTER OF 1019 MB IS CENTERED AT 31N74W. BROAD UPPER TROUGHING EXISTS TO THE N OF THE TROUGH. LATEST SATELLITE IMAGERY AND NWS DOPPLER RADAR DISPLAYS SHOW ABUNDANT DEEP LAYER MOISTURE COVERING JUST ABOUT THE AREA RESULTING IN WIDESPREAD RAIN AREAS WITH EMBEDDED SHOWERS AND SCATTERED TSTMS WITH POSSIBLE GUSTY WINDS. A TIGHT PRES GRADIENT BETWEEN HIGH PRES TO THE N OF THE FRONT AND A BROAD LOW PRES SYSTEM OVER THE SE GULF AND W CUBA IS ALLOWING FOR E WINDS OF 20-25 KT TO THE S OF 27N AND W OF ABOUT 76W AND HIGHER WINDS OF 25-30 KT BETWEEN CUBA AND THE FLORIDA KEYS WHERE SEAS ARE IN THE RANGE OF 8-11 FT. ELSEWHERE BUOY REPORTS ALONG WITH A FEW SHIP OBSERVATIONS AND PARTIAL ASCAT DATA SHOW LIGHTER E WINDS OF GENERALLY 10-15 KT...WITH WIND DIRECTION FROM NE-E TO THE E OF 71W. SEAS ARE IN THE RANGE OF 3-5 FT. MODEL GUIDANCE SUGGESTS THAT THE E WINDS OF 20-25 KT WILL DECREASE TO 15-20 KT WITHIN THE NEXT 12-18 HRS AS THE PRES GRADIENT OVER THE AREA WEAKENS. THE HIGH AT 31N WILL WEAKEN AS RETREATS NE THROUGH TUE IN ADVANCE OF THE GULF OF MEXICO LOW PRES SYSTEM THAT ACCELERATES NEWD TO OVER THE SE U.S. OR THE COAST...AND WHILE A COLD FRONT THAT QUICKLY SWEEPS THROUGH THE GULF EMERGES OFF THE NE TUE NIGHT. A STRONG PRES GRADIENT FORMS OVER THE NW WATERS E OF THE FRONT TUE KICKING OFF SLY WINDS 20-30 KT ...TO HIGHER RANGES IN THE GALE FORCE RANGE OF 30-35 KT BY TUE EVENING TO THE N OF 28N E OF THE COLD FRONT FORECAST TO EXTEND FROM NEAR 31N78W TO S FLORIDA BY LATE WED AFTERNOON. LATEST ENSEMBLE 34 KT WIND PROBABILITIES STILL REVEAL 50-80 PERCENT AND THE RECENT SREF PROBABILITIES UP TO 40 PERCENT ALONG 31N FOR TUE NIGHT INTO WED AFTERNOON AT WHICH TIME THE SLY GALE WINDS SHOULD DIMINISH TO 25-30 KT. THE FRONT WILL REACH FROM 31N74W TO CENTRAL CUBA BY EARLY THU AS IT BEGINS TO WEAKEN AND SLOW DOWN. BY FRI IT SHOULD TRANSITION TO A STATIONARY FRONT FROM NEAR 31N7OW TO EASTERN CUBA. W-NW 20-25 KT WINDS ARE EXPECTED BEHIND THE FRONT EARLY WED INTO EARLY THU...THEN QUICKLY DIMINISH TO 10-15 KT LATE THU THROUGH FRI AS HIGH PRES BUILDS IN FROM THE WNW WHILE THE FRONT CONTINUES ON A WEAKENING TREND. 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 AGUIRRE