000 AGXX40 KNHC 180729 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 1002 MB LOW CENTER JUST N OF THE YUCATAN PENINSULA NEAR 23N89W WITH A PRES OF 1002 MB IS PART OF AN AREA OF LOW THAT IS BECOMING ELONGATED NNE FROM S FLORIDA TO THE YUCATAN PENINSULA. A TIGHT PRES GRADIENT BETWEEN THE LOW PRES AREA AND HIGH PRES RIDGING TO THE NE IS CONTINUING TO MAINTAIN MINIMAL GALE FORCE WINDS TO THE NE AND E OF THE LOW FROM 23N TO 28N AND E TO NEAR 83W. BUOY 42003 AT 26N86W IS REPORTING SUSTAINED SE WINDS OF 31 KT WITH A PEAK WIND GUST OF 37 KT WITHIN THE PAST HOUR WITH A COMBINED SEA HEIGHT OF 10 FT. VERY DEEP CONVECTION TO THE E AND NE OF THE LOW IS APPROACHING THE SW FLORIDA COAST AS SEEN ON SATELLITE AND RADAR DATA. SEAS ARE IN THE RANGE OF 8-12 WITHIN THE GALE AREA TO THE NE AND E OF THE LOW. SEAS ELSEWHERE OVER THE E GULF ZONE WINDS ARE SE-S 20-25 KT WITH SEAS TO 8 FT. THE LOW IS FORECAST TO POSSIBLY REFORM FURTHER TO THE NE TODAY..AND MOVE QUICKLY NE TOWARDS W CENTRAL FLORIDA TONIGHT. GALE WINDS ARE EXPECTED TO DIMINISH TO JUST BELOW GALE FORCE EARLY THIS EVENING AS THE LOW NOW HAS A LOW PROBABILITY OF INTENSIFYING INTO A TROPICAL CYCLONE OVER THE NEXT 48 HRS. WINDS OVER THE REMAINDER OF THE GULF ARE E-SE 10-15 KT...EXCEPT S OF 28N BETWEEN 87W AND 91W WHERE N-NE WINDS OF 15-20 KT ARE NOTED PER BUOY AND ASCAT DATA. SEAS THERE ...AND IN THE FAR NE GULF ARE 5-7 FT IN A NE SWELL. SEAS ELSEWHERE ARE 3-5 FT. THE NEXT MAJOR FEATURE TO AFFECT THE GULF WILL BE A STRONG COLD FRONT EXPECTED TO MOVE INTO THE FAR NW GULF EARLY THIS MORNING. THIS FRONT WILL QUICKLY MOVING SE REACHING FROM THE FLORIDA KEYS TO THE YUCATAN PENINSULA BY WED AFTERNOON ON THE HEALS OF THE DEPARTING LOW PRES SYSTEM. IT WILL THEN PUSH SE INTO THE WESTERN CARIBBEAN LATER ON WED. STRONG NORTHERLY WINDS WILL ARRIVE BEHIND THE FRONT WITH POSSIBLE GUSTS TO NEAR GALE FORCE OVER THE FAR NRN WATERS...AND NW-N WINDS GALE WINDS OF 25-35 KT IN THE FAR SW GULF ZONE IN THE AREA OF S OF 21N W OF 95W TO BEGIN ON WED AS THE COLD AIR MASS FOLLOWING THE FRONT MOVES OVER THE WARM WATERS OF THE GULF AND INDUCES THE NECESSARY INSTABILITY TO RESULT IN THE FORECAST GALE WINDS THERE. HIGH PRES BUILDS IN BEHIND THE FRONT LATE WED THROUGH SAT WITH WINDS GRADUALLY DIMINISHING FROM NW TO SE...DOWN TO 10-15 KT BY WED EVENING AS THE AIRMASS QUICKLY MODIFIES AND AS THE HIGH SINKS BACK DOWN OVER THE LOWER MISSISSIPPI VALLEY. ON THU WINDS BECOME E-SE IN DIRECTION IN THE FAR NW GULF ZONE AND CONTINUE TO SAT AT A SPEED OF 10-15 KT. CARIBBEAN SEA AND TROPICAL N ATLC... NOW THAT THE GULF OF MEXICO LOW HAS MOVED FATHER AWAY FROM THE CARIBBEAN SEA...THE GRADIENT HAS RELAX SOME IN THE FAR NW PORTION. BUOY 42056 AT 19.8N85W IS REPORTING S WINDS OF 20 KT WITH SEAS OF 6-7 FT. A SHIP JUST TO ITS HAS WINDS OF S-SW AT 20-25 KT. THE REMAINDER OF THE CARIBBEAN SEA IS UNDER MAINLY E WINDS OF 10-15 KT WINDS UNDER A RATHER WEAK PRES PATTERN. THE WINDS IN THE NW CARIBBEAN WILL SHIFT 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 INTO THE YUCATAN CHANNEL EARLY WED AFTERNOON...AND REACH FROM CENTRAL CUBA TO THE GULF OF HONDURAS WED EVENING...THEN FROM CENTRAL CUBA TO NE NICARAGUA BY THU EVENING. THE FRONT WILL BECOME STATIONARY FRI AND SAT 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 IS OVER THE EASTERN CARIBBEAN SEA ALONG 67W/68W S OF 17N. SCATTERED SHOWERS AND ISOLATED TSTMS ARE NOTED E OF THE WAVE AXIS. THE WAVE WILL DAMPEN AND DISSIPATE OVER THE E CARIBBEAN THROUGH WED NIGHT. NE-E 15-20 KT WINDS AND SEAS TO 8 FT SHOULD CONTINUE THROUGH THU ACROSS THE MIDDLE TROPICAL N ATLC IN THE WAKE OF THE WAVE. ANOTHER TROPICAL WAVE WILL APPROACH THE TROPICAL N ATLC THU...AND THE LESSER ANTILLES EARLY FRI...AND INTO THE EASTERN CARIBBEAN SAT. SW N ATLC S OF 31N W OF 55W... THE 0600 UTC SURFACE ANALYSIS SHOWS A STATIONARY FRONT EXTENDING FROM 31N66W TO THE NORTHERN BAHAMAS AND W 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 CENTRAL 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... .GMZ084 AND GMZ086...GALE WARNING FROM 22N TO 28N BETWEEN 83W AND 85W... .GMZ082...GALE CONDITIONS EXPECTED S OF 21N W OF 95W EARLY WED... .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLC... .AMZ080...GALE WARNING N OF 28N BETWEEN 74W AND COLD FRONT... FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE