000 AGXX40 KNHC 291900 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 256 PM EDT TUE MAR 29 2016 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: 12 UTC GFS BLEND WITH PREVIOUS OFFICIAL FOR WINDS THROUGH THU...THE GFS/ECMWF BLEND THU NIGHT THROUGH SUN NIGHT. 12 UTC MWW3/TAFB WAVE PARAMETERS FOR WAVEHEIGHTS. HIGH CONFIDENCE THROUGH THU...AVERAGE CONFIDENCE THU NIGHT THROUGH SUN NIGHT. A DISSIPATING STATIONARY FRONT EXTENDS FROM NEAR PUNTA GORDA FL SW TO 26N87W AND TO 24N93W. A DIURNAL TROUGH MOVED OFF THE YUCATAN PENINSULA LAST NIGHT...AND IS ALONG 93W S OF 23N. SATELLITE IMAGERY IS SHOWING CLUSTERS OF STRONG TSTMS IN LINEAR TYPE FASHION ACROSS THE ERN GULF N OF 24N AND E OF 86W. THE SATELLITE LIGHTNING DENSITY PRODUCT IS EXHIBITING AN EXTENSIVE AMOUNT OF LIGHTNING WITH THIS ACTIVITY AS IT RACES EWD. BUOY 42003 AT 26N86W REPORTED A WIND GUST OF 29 KT FROM THE NW LATE THIS MORNING AS THE SRN TIER OF THE ACTIVITY PASSED OVER IT. THE TSTM ACTIVITY IS ASSOCIATED WITH A RATHER ROBUST MID-LEVEL SHORTWAVE TROUGH PROVIDING FORCING FOR ASCENT MOVING OVER THE ERN PART OF THE GULF. IN ADDITION...THE STATIONARY FRONTAL BOUNDARY IS SERVING AS A SURFACE FOCUS MECHANISM TO SUPPORT THE ACTIVITY. THE TSTM ACTIVITY IS EXPECTED TO MOVE E OF THE GULF TONIGHT INTO WED. THE FORECAST CALLS FOR THE REMNANTS OF THE STATIONARY FRONT TO LIFT BACK TO THE N AS A WARM FRNT ON WED AND WED NIGHT AS MODERATE TO STRONG SOUTHEASTERLY RETURN FLOW DEVELOPS ACROSS MUCH OF THE GULF. THE MODERATE TO STRONG SOUTHEASTERLY WINDS THEN DIMINISH ON THU. THE NEXT COLD FRONT SHOULD REACH THE NW GULF EARLY ON FRI FOLLOWED BY STRONG N TO NE WINDS. BY LATE FRI...THE FRONT WILL QUICKLY WEAKEN AS IT REACHES FROM NEAR THE WRN FL PANHANDLE TO THE CENTRAL GULF WHERE IT SHOULD BECOME STATIONARY TO THE SW GULF. MODELS ARE IN VERY GOOD AGREEMENT THAT HIGH PRES BEHIND THE FRONT WILL BE REINFORCED BY STRONGER HIGH PRES FRI NIGHT AND SAT ALLOWING FOR MODERATE TO STRONG N TO NE WINDS TO AFFECT THE NW GULF...AND MOST OF THE N CENTRAL GULF PORTIONS SHIFTING TO THE ERN PART OF THE CENTRAL GULF SUN. THERE ARE SOME DIFFERENCES BETWEEN THE GFS AND ECMWF MODELS WITH RESPECT TO THE FRONTAL PSN SAT AND SUN WITH THE ECMWF BEING MORE PROGRESSIVE IN MOVING THE FRONT TO THE S GULF OF THE GULF BY SUN NIGHT...AND THE GFS HANGING THE FRONT BACK ACROSS S FL AND THE CENTRAL GULF AS A STATIONARY FRONT WITH BROAD LOW PRES TO IT S OVER THE CENTRAL GULF. TO REMEDY THESE DIFFERENCES A BLEND OF THE GFS/ECMWF FOR LONG TERM PART OF THE FORECAST WILL BE INCORPORATED INTO THE WIND GRIDS. THIS WILL DEPICT A SLOWER MOVING FRONTAL BOUNDARY ACROSS THE ERN GULF AND SURROUNDING WATERS. THE GRADIENT WILL BE TIGHT ENOUGH BEHIND THE FRONT ON SAT AND SUN TO ALLOW FOR AT LEAST MODERATE NE WINDS WITH SEAS OF ABOUT 5-7 FT OVER MUCH OF THE GULF AT THOSE TIMES. WILL ADJUST GRIDS ACCORDINGLY PENDING UPDATED MODEL DATA FOR LONG TERM PERIODS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12 UTC GFS BLEND WITH PREVIOUS OFFICIAL FOR WINDS. 12 UTC MWW3/TAFB WAVE PARAMETERS FOR WAVEHEIGHTS. HIGH CONFIDENCE. THE PRES GRADIENT BETWEEN A 1025 MB BERMUDA HIGH AND A 1006 MB COLOMBIA LOW ARE PRODUCING GENERALLY MODERATE TO FRESH BREEZE CONDITIONS ACROSS THE CARIBBEAN WITH LOCALLY STRONG E TO SE WINDS IN THE GULF OF HONDURAS. WINDS NEAR THE COAST OF COLOMBIA ARE GRADUALLY DIMINISHING WITH ONLY A SMALL POCKET OF STRONG NE TO E WINDS S OF 12N BETWEEN 74W AND 76W. A RECENT ALTIMETER PASS ALONG WITH BUOY 42058 AT 15N75W VERIFIED SUBSIDING SEAS AS WELL WITH MAX WAVE HEIGHTS WITHIN 8-9 FT WITH THE EXCEPTION OF 8-10 FT SEAS WITHIN THE SMALL POCKET OF STRONG WINDS. THE 8-10 FT SEAS ARE FORECAST TO LOWER FURTHER TO 8 FT BY LATE NIGHT. THE TRADES ARE FORECAST TO DIMINISH OVER THE CENTRAL CARIBBEAN WED NIGHT AND THU. WINDS IN THE GULF OF HONDURAS WINDS ARE FORECAST TO PULSE WHILE INCREASING TO STRONG WINDS THROUGH SAT AS HIGH PRE BUILDS OVER THE SE UNITED STATES. MODERATE TO FRESH TRADES OVER THE TROPICAL N ATLC ARE EXPECTED TO CHANGE LITTLE THROUGH SUN. WINDS OVER THE TROPICAL N ATLC ARE MODERATE TO FRESH BREEZE EASTERLIES. THIS WILL NOT CHANGE MUCH DURING THE NEXT SEVERAL DAYS. SOME EASTERLY SWELL WILL COMBINE WITH THE LOCAL WIND WAVES TO PRODUCE SEAS GENERALLY 6-8 FT OVER THE NEXT SEVERAL DAYS. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12 UTC GFS BLEND WITH PREVIOUS OFFICIAL FOR WINDS. 12 UTC MWW3/TAFB WAVE PARAMETERS FOR WAVEHEIGHTS. HIGH CONFIDENCE. THE PRELIMINARY 18 UTC ANALYSIS HAS A COLD FRONT FROM NEAR 31N67W SW TO 28N76W WHERE IT BECOMES A DISSIPATING STATIONARY FRONT TO S CENTRAL FL. SATELLITE IMAGERY SHOWS SCATTERED TSTMS ALONG AND WITHIN 300 NM E OF THE FRONT E OF 73W. WINDS ON EITHER SIDE OF THE FRONT ARE IN THE GENTLE TO MODERATE RANGE WITH SEAS OF 4-6 FT. THE COLD FRONT WILL REACH FROM NEAR 30N65W TO 27N71W LATE TONIGHT WHILE THE STATIONARY PORTION BEGINS TO WEAKEN. THE FRONT WILL MOVE E OF THE AREA BY WED EVENING AS A STRONG HIGH PRES RIDGE BUILDS S ACROSS THE NRN AND CENTRAL WATERS. THE RIDGE WILL SHIFT EWD THROUGH FRI NIGHT IN RESPONSE TO THE NEXT COLD FRONT THAT MOVES ACROSS THE SE UNITED STATES. MODELS ARE IN GOOD AGREEMENT THAT THE GRADIENT WILL SUPPORT FRESH NE TO E WINDS OVER THE NRN AND CENTRAL WATERS WED AND WED NIGHT. THESE WINDS WILL VEER TO E/SE THU AND THU NIGHT OVER THE NE WATERS BEFORE DIMINISHING EARLY ON FRI. THIS NEXT COLD FRONT IS FORECAST TO MOVE OVER THE FAR NW WATERS ON SAT PRECEDED BY INCREASING SW WINDS OF FRESH INTENSITY AND SEAS OF 6-8 FT. THE FRONT...LIKE RECENT ONES...WILL QUICKLY MOVE ACROSS THE NRN WATERS THROUGH LATE SUN WITH THE SW WINDS AHEAD OF IT DIMINISHING...AND FOLLOWED BY GENERALLY LIGHT TO MODERATE NLY WINDS. SEAS ARE EXPECTED TO BE IN THE RANGE OF 4-6 FT N AND E OF THE BAHAMAS SAT AND SUN...AND 1-3 FT SW OF THE BAHAMAS. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER AGUIRRE. NATIONAL HURRICANE CENTER.