000 AGXX40 KNHC 131846 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 246 PM EDT WED APR 13 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. FOR WAVEHEIGHTS USED 12 UTC MWW3 AND A SMALL PERCENTAGE OF NWPS WAVE PARAMETERS BLEND WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. THE LATEST SURFACE ANALYSIS SHOWS WEAKENING HIGH PRES OVER THE NE GULF. A WEAK STATIONARY FRONTAL BOUNDARY EXTENDS FROM N CENTRAL FLORIDA WESTWARD TO 29N85W...TO ACROSS SOUTHERN LOUISIANA...AND TO SW TO JUST ALONG THE TEXAS COAST. BOTH CURRENT NWS DOPPLER RADAR IMAGERY AND LATEST SATELLITE IMAGERY ARE SHOWING SCATTERED TO NUMEROUS SHOWERS AND TSTMS QUICKLY MOVING EASTWARD ACROSS THE NW AND N CENTRAL GULF. LIGHTNING DATA DENSITY FROM THE GOESR PROVING GROUND IS REVEALING LIGHTNING STRIKES WITH THE SHOWER AND TSTM ACTIVITY. THE LIGHTNING APPEARS TO BE DIMINISHING SOME OVER THE PAST FEW HOURS AS THE COVERAGE OF THE SHOWER/TSTM ACTIVITY SHRINKS IN COVERAGE. THE LATEST BUOY OBSERVATIONS ARE REPORTING GENTLE TO MODERATE SE WINDS THROUGHOUT...WITH SEAS IN THE RANGE OF 3-4 FT N OF 21N W OF 90W...2-3 FT SEAS IN THE CENTRAL GULF AND 1-2 FT SEAS IN THE EASTERN PORTION. LATEST MODEL GUIDANCE SHOWS THE HIGH PRES CONTINUING TO WEAKEN THROUGH THU ALLOWING FOR THE FRONTAL BOUNDARY TO SAG SLIGHTLY S OVER THE N CENTRAL AND NE GULF PORTIONS. MODELS ARE IN GOOD AGREEMENT THAT WEAK LOW PRES FORMS ALONG THE FRONT THIS AFTERNOON NEAR NE TEXAS COAST...AND LIFT NEWD TO NEAR THE SW LOUISIANA COAST BY THU AFTERNOON. THE GUIDANCE SHOWS THAT NO SIGNIFICANT IMPACTS TO WINDS AND SEAS IS EXPECTED FROM THIS FEATURE. WITH FAVORABLE UPPER LEVEL DYNAMICS IN PLAY FORECAST TO PERSIST THROUGH LATE THU EXPECT THE AFOREMENTIONED SCATTERED SHOWER AND TSTM ACTIVITY TO RE-DEVELOP THIS AFTERNOON AND INTO TONIGHT AS IT TRANSLATES EASTWARD ACROSS THE GULF. THIS ACTIVITY WILL BE ATTENDED BY POSSIBLE WIND GUSTS TO AROUND 30 KT. BEGINNING ON LATE THU NIGHT...MODEL GUIDANCE IS IN VERY GOOD AGREEMENT THAT STRONG HIGH PRES WILL BEGIN TO BUILD SWD INTO THE NE GULF...THEN BUILD SSW TO THE MUCH OF THE CENTRAL AND NW GULF BY LATE SAT AND THOUGH SUN. THIS WILL TAKE PLACE WHILE LOW PRES DEEPENS OVER THE PLAINS. THE END RESULT WILL BE A TIGHTENING OF THE PRES GRADIENT OVER THOSE WATERS LEADING TO AN INCREASE OF NE-E WINDS THERE...AND INCREASING E-SE WINDS IN THE PORTION. THE DURATION AND FETCH OF THESE WINDS IS EXPECTED TO BE LONG ENOUGH TO ALLOW FOR SEAS TO BUILD TO POSSIBLY 9 FT IN THE NW GULF BY LATE SAT. LATE SUN INTO MON...THE GRADIENT SLACKENS ALLOWING FOR WINDS TO DIMINISH AND SEAS TO SLOWLY SUBSIDE TO AROUND 5-7 FT. A SURFACE TROUGH WILL DEVELOP OVER THE YUCATAN PENINSULA EACH AFTERNOON THROUGH FRI...AND MOVE ACROSS THE SW GULF WHILE IT WEAKENS IN THE OVERNIGHT HOURS. THE ASSOCIATED GRADIENT WITH THIS FEATURE WILL PRODUCE STRONG E-SE WINDS ALONG THE COAST OF THE YUCATAN PENINSULA EACH NIGHT THROUGH THE PERIOD. ...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. FOR WAVEHEIGHTS USED 12 UTC MWW3 AND A SMALL PERCENTAGE OF NWPS WAVE PARAMETERS BLEND WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. WIND AND SEA CONDITIONS REMAIN AT RATHER LOW RANGES THROUGHOUT AS THE PRES GRADIENT REMAINS WEAK DUE TO BROAD LOW PRES DOMINATING THE SW N ATLC E OF THE BAHAMAS. THIS WAS CONFIRMED BY THIS MORNING'S 1100 UTC WINDSAT PASS AND AN ASCAT PASS FROM 1416 UTC THAT DEPICTED GENTLE E-SE WINDS E OF 65W...AND MAINLY GENTLE NE-E WINDS W OF 65W EXCEPT FOR A SMALL PATCH OF MODERATE NE WINDS THROUGH THE WINDWARD PASSAGE AND E-SE GENTLE TO MODERATE WINDS W OF 83W. BOTH LATEST AND CURRENT BUOY WIND OBSERVATIONS AGREE WITH THE OBSERVED WINDSAT AND ASCAT DATA. SEAS THROUGHOUT THE AREA ARE IN THE 3-5 FT RANGE...WITH THE EXCEPTION OF 5-6 FT SEAS IN THE TROPICAL N ATLC AREA. LOWER SEAS OF 2-3 FT ARE IN THE FAR NE AND NW CARIBBEAN PORTIONS. THE FORECAST WILL VARY LITTLE FROM THE PRESENT OBSERVED ONGOING CONDITIONS THROUGH FRI. NE TRADES INCREASE TO 20-25 KT NEAR THE COAST OF COLOMBIA SAT NIGHT AND DIMINISH ON SUN. ONLY A SMALL POCKET OF THESE WINDS IS EXPECTED NEAR THE COAST OF COLOMBIA EARLY ON MON. E-SE WINDS OVER THE GULF OF HONDURAS WILL BEGIN TO PULSE TO THE FRESH INTENSITY THU THROUGH SAT...BECOMING LOCALLY STRONG SAT NIGHT BEFORE DIMINISHING TO MODERATE INTENSITY SUN AND PULSING BACK UP TO STRONG ON MON. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS FOR WINDS. FOR WAVEHEIGHTS USED AN EVEN BLEND OF USED 12 UTC MWW3 AND NWPS WAVE PARAMETERS INTO PREVIOUS OFFICIAL. HIGH CONFIDENCE. THE PRELIMINARY 18 UTC ANALYSIS HAS A DISSIPATING LOW PRES E OF NE FLORIDA NEAR 30N79W WITH A WEAK FRONTAL TROUGH EXTENDING FROM IT SW TO NEAR MELBOURNE FLORIDA. THE TROUGH APPEARS TO BE ALIGNING ITSELF N TO S ALONG THE COAST OF N AND CENTRAL FLORIDA. THE ANALYSIS DEPICTS BROAD LOW PRES OVER THE THE SE PORTION IN ASSOCIATION WITH A WEAL 1013 MB LOW E OF THE BASIN NEAR 24N63W. A TROUGH EXTENDS SW FROM THIS LOW TO JUST N OF PUERTO RICO. THE LOW WILL MOVE NE FURTHER AWAY FROM THE AREA THROUGH FRI... BUT WILL TRAIL A TROUGH SW TO THE FAR NW PART OF THE TROPICAL N ATLC EARLY FRI BEFORE IT PULLS OFF TO THE NE OF THOSE WATERS ON SAT WITH LITTLE IF ANY IMPACT ON WINDS AND SEAS IN THE FAR SE PART OF THE BASIN. THE MODEL GUIDANCE INDICATES THAT THE TROUGH ALONG THE FLORIDA COAST WILL REMAIN STATIONARY THROUGH THU...THEN SLOWLY SHIFT INLAND FRI WHILE WEAKENING. THERE IS A POTENTIAL THAT A WEAK LOW MAY FORM ON THE TROUGH ON THE TROUGH LATE THU...AND DRIFT S THROUGH LATE FRI AS IT DISSIPATES. SEAS OVERALL REMAIN RELATIVELY LOW...IN THE 4-6 FT E AND NE OF THE BAHAMAS AND 1-2 FT SW OF THE BAHAMAS. HIGHER SEAS OF 6-7 FT IN NE SWELL ARE N OF 24N E OF 72W. THE ASCAT PASS FROM 1412 UTC SHOWED GENTLE ELY WINDS E OF THE BAHAMAS...AND GENTLE TO MODERATE E-SE WINDS W OF THE BAHAMAS. WINDS N OF THE LOW E OF FLORIDA ARE MODERATE FROM THE N-NE. THE FRONTAL TROUGH OVER THE NW WATERS WILL SAG SWD A LITTLE REACHING ALONG 29N BY THU AFTERNOON...AND FROM NEAR 28N65W NW TO 25N69W...AND NW AS DISSIPATING STATIONARY FRONT TO NEAR 29N80W BY LATE FRI. A TIGHT PRES GRADIENT OVER THE FAR NW WATERS NE OF JAX FLORIDA WILL MAINTAIN MODERATE MODERATE NE WINDS THERE THROUGH THU NIGHT. MODELS ARE CONSISTENTLY DEPICTING THAT STRONG HIGH PRES WILL BUILD S INTO THE NW AND N CENTRAL WATERS FRI THROUGH SUN WITH THE RESULTANT TIGHT PRES GRADIENT LIKELY EXPECTED TO INCREASE THE NE WINDS TO THE E OF NE FLORIDA TO THE STRONG RANGE. THE GRADIENT WILL RELAX ON MON. SEAS ARE FORECAST TO BUILD TO RATHER HIGH VALUES IN THE RANGE OF 9-14 FT NE OF THE BAHAMAS BY SUN PER MWW3/NWPS OUTPUT. SEAS SHOULD SUBSIDE TO 8-12 FT MON. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.