000 AGXX40 KNHC 130809 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 409 AM EDT MON APR 13 2015 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: GLOBAL MODEL CONSENSUS CUT OFF LOW ACROSS SW U.S. AND ASSOCIATED S/W ENERGY MOVING THROUGH BASE KICKING OFF LARGE CLUSTERS OF TRW+ ACROSS NE MEXICO AND S TEXAS OVERNIGHT THAT PERSIST IN DIFFLUENT FLOW ALOFT...AND HAVE SHIFTED E AND INTO TEXAS OFFSHORE WATERS THIS MORNING. UPPER LOW TO SHIFT SLOWLY ENE NEXT 36 HRS WITH JET ENERGY SHIFTING EWD ACROSS NRN GULF AND N HALF OF FL FOR CONTINUED TRW+ POTENTIAL ACROSS N PORTIONS OF THE BASIN THROUGH WED. MODERATE RETURN FLOW PREVAILS ACROSS ALL BUT NE PORTIONS THIS MORNING..WITH FRESH TRADES OFF NW COAST OF YUCATAN DUE THE THERMAL TROUGH SHIFTING WWD OFF THE PENINSULA. SEAS GENERALLY 2-3 FT EXCEPT 3-5 FT SW PORTIONS AND OFFSHORE OF NW YUCATAN. LITTLE CHANGE IN OVERALL LLVL SYNOPTIC PATTERN EXPECTED THROUGH THU...ALTHOUGH EXTENDED PERIOD OF PERSISTENT RETURN FLOW WILL RAISE SEAS 1-2 FT FROM CURRENT VALUES W HALF. WINDS TO PULSE EACH LATE AFTERNOON THROUGH THE NIGHT OFF N AND W COASTAL ZONES OF YUCATAN THEN SHIFT NW AS THERMAL TROUGH SHIFTS OVER WATER. OTHERWISE...CONVECTIVE POTENTIAL FOR TRW+ OR SEVERE TRW MAIN THREAT ACROSS THE BASIN NEXT FEW DAYS. GLOBAL MODELS HAVE TRENDED TOWARD RECENT ECMWF SOLUTIONS AND NOW FRONTAL BOUNDARY DOES NOT GET INTO TEXAS COASTAL ZONES THU OR FRI AND THUS NO MENTION. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS WEAKENED ATLC RIDGE BEING OVERTAKEN ACROSS W ATLC BY HIGH SHIFTING E OFF MID ATLC COAST NOW RIDGING MODESTLY S TO FRONTAL REMNANTS LINGERING ALONG 29-30N W OF 70W. THIS IS MAINTAINING FRESH TO LOCALLY STRONG TRADES ACROSS CENTRAL PORTIONS PER RECENT OBS AND SCAT PASSES. TRADES HAVE ALSO FRESHENED 2-3 KT W PORTIONS PAST 24 HRS AND COMBINED WITH ELY TRADE WIND SWELL MOVING INTO REGION FOR SLIGHT INCREASE IN SEAS AS WELL...WITH 42057 HOLDING AT 5 FT AND 42056 AT 4 FT. HIGH OFF MID ATLC COAST TO GRADUALLY SHIFT ENE NEXT FEW DAYS BUT MAINTAIN RIDGE S THEN SW TO FLORIDA TO KEEP FRESH TO STRONG TRADES ACROSS CENTRAL PORTIONS THROUGH TUE NIGHT BEFORE WINDS BEGIN TO WEAKEN THERE SLIGHTLY WED THROUGH FRI THEN WEAKEN FURTHER OVER THE WEEKEND AS SIGNIFICANT FRONTAL SYSTEM SINKS S INTO CENTRAL ATLC. SUFFICIENT RIDGING LOOKS TO REMAIN IN PLACE THROUGH THE PERIOD INTO NW CARIB TO ALLOW WINDS TO PULSE TO 20-25 KT EACH NIGHT ACROSS GULF OF HONDURAS...WHERE SEAS WILL LIKELY BUILD BRIEFLY TO NEAR 8 FT MOST NIGHTS. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS THROUGH DAY 3 THEN ECMWF RIDGE HAS WEAKENED TO THE SE OF WEAKENING FRONTAL ZONE LINGERING ALONG 29-30N THIS MORNING. 1027-28 MB HIGH SHIFTING E OFF OF MID ATLC COAST NOW RIDGING S TO FRONTAL ZONE AND WILL SHIFT ENE NEXT FEW DAYS WITH RIDGE EXPECTED TO CONTINUE FROM HIGH TO N CENTRAL FLORIDA. THIS TO MAINTAIN FRESH TRADES S OF 20N AND PULSING 20-25 KT EACH LATE AFTERNOON EVENING ALONG N COAST OF HISPANIOLA...AND TO LESSER EXTENT ALONG N COASTAL ZONES OF ALL GREATER ANTILLES. AS HIGH SHIFTS ENE E PORTIONS OF CURRENT FRONT TO SINK S TO ALONG 30N E OF 65W TONIGHT. DIGGING DEEP LAYERED TROUGH THEN SWEEPING SE INTO CENTRAL ATLC TO CARVE WEAKNESS 40W-50W THAT IS HANDLED DIFFERENTLY BY GLOBAL MODELS...BUT ALL AGREE IN NARROWING RIDGE SW INTO SW N ATLC WATERS AS STRONG FRONTAL SYSTEM MOVES SSE ACROSS NW ATLC WED NIGHT-THU...THEN BOMB DEVELOPS CENTRAL ATLC ALONG ABOUT 40N THU-FRI. ECMWF HAS BEEN CONSISTENT IN ITS SOLUTION DURING THIS PERIOD AND NOW GFS EASING IN THAT DIRECTION SO WILL CONTINUE TO FOLLOW ECMWF. HAVE A 50-50 GFS-ECMWF BLEND BEYOND WED FOR ATLC N OF WEAK RIDGE ALONG 24-25N. THERE IS SLIGHT POTENTIAL FOR POCKETS OF BRIEF GALES N OF FRONT THU AND THU NIGHT WITH SIGNIFICANT LATE SEASON SWELL EVENT THEN ENSUING THROUGH THE WEEKEND. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 STRIPLING. NATIONAL HURRICANE CENTER.