000 AGXX40 KNHC 120811 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 411 AM EDT SUN APR 12 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 WEAKENING FRONTAL BOUNDARY STALLED ACROSS N GULF FROM BIG BEND TO LOUISIANA COASTAL WATERS THEN APPEARS ILL DEFINED WWD INTO TEXAS WATERS AS OBS SHOW SFC WINDS NOW SE ACROSS ALL TEXAS WATERS. S/W MOVING ACROSS NW MEXICO AND APPROACHING W TEXAS ATTM IS AHEAD OF DIGGING DEEP LAYERED VORT LOBE SWEEPING INTO BAJA CALIFORNIA ATTM AND CONTINUES TO AID IN TRIGGERING DEEP CONVECTIVE CLUSTERS ACROSS NE MEXICO...WITH RECENT BRO RADAR SUGGESTING MCC FALLING APART AS IT MOVED S OF THE BRO AREA. ASSOCIATED MOISTURE AND INSTABILITY IN PLACES ACROSS NW GULF WILL SHIFT SLOWLY N AND NE TODAY THROUGH TONIGHT AND BEGIN TO REFOCUS CONVECTION ACROSS N CENTRAL PORTIONS AND INTO LOWER MS VALLEY TONIGHT. LIGHT TO MODERATE SE FLOW GENERALLY PREVAILS AT THE SFC ACROSS THE BASIN ATTM YIELDING SEAS 2-3 FT ACROSS ALL BUT BIG BEND REGION WHERE SEAS ARE AROUND 1 FT. LLVL FLOW EXPECTED TO GRADUALLY VEER MORE SLY W HALF BY AFTERNOON WITH FRONTAL REMNANTS DRIFTING ALONG THE COAST AND EVENTUALLY INLAND TONIGHT. THIS PATTERN TO THEN PREVAIL ACROSS THE BASIN THROUGH FRI WHEN VIGOROUS DEEP LAYERED LOW SHIFTS E ACROSS SOUTHERN PLAINS AND INTO TEXAS...FOR LIKELY SEVERE WX OUTBREAK ACROSS THE REGION AND ASSOCIATED FRONTAL BOUNDARY APPROACHING FROM W. CONFIDENCE LOWERS WITH FORECAST BEYOND THU AS ACTIVE SRN STREAM FLOW ACROSS SW U.S. YIELDING DIFFERINGSOLUTIONS WITH GLOBAL MODELS...AND WILL HAVE TO RESPECT ECMWF AND LINGERING CUT OFF LOW FRI-SAT. OTHERWISE...ONLY FEATURE EXPECTED TO PRODUCE FRESH TO STRONG WINDS ACROSS BASIN WILL CONTINUE TO BE AFTERNOON THERMAL TROUGH OVER THE YUCATAN PENINSULA THAT WILL SHIFT NW EACH EVENING. LOOK FOR 20-25 KT SEABREEZE THERE EACH LATE AFTERNOON AND EVENING...WITH SEAS BUILDING 4-6 FT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS ATLC RIDGE CONTINUES WEAKLY ALONG 29N...CENTERED ON 1026 MB HIGH NEAR 29.5N51W. RIDGE COMBINING WITH LOW PRES OVER NW COLOMBIA TO MAINTAIN FRESH TRADES ACROSS CENTRAL PORTIONS OF BASIN...AND 25 TO NEAR 30 KT ALONG COLOMBIAN COASTAL WATERS AND IN GULF OF VENEZUELA. THESE WINDS AND ASSOCIATED PRES GRADIENT HAVE WEAKENED SLIGHTLY PAST 24 HOURS...AND GALES NOT EXPECTED OFF OF COLOMBIA IN NEXT SEVERAL DAYS. 23Z ALTIMETER PASS SHOWED SEAS TO 8 FT EXTENDING AS FAR N AS 17.5N...AND VERIFYING INFLUENCE OF ENHANCED TRADES ACROSS NEAR AND OFFSHORE CARIB COASTAL WATERS OF HISPANIOLA. ATLC RIDGE BUILDING MILDLY ACROSS NE CARIB AND ADJACENT ATLC WATERS ATTM BEHIND PASSING INVERTED TROUGH TO THE N...AND INCREASING WINDS TO AROUND 20 KT ACROSS NE PORTIONS...WITH SCT PASSING TRADE WIND SHOWERS. THIS PATTERN TO HOLD IN TACT THROUGH WED BEFORE ATLC HIGH SHIFTS NE AND NW HIGH AND REORGANIZING RIDGE SINK INTO CENTRAL ATLC AND RE-ESTABLISH ALONG ABOUT 26-27N. TRADES EXPECTED TO WEAKEN ACROSS MOST OF BASIN WED- THU. WEAK RIDGING ACROSS GULF OF MEXICO WILL INFLUENCE PRES GRADIENT W PORTIONS AND ALLOW WINDS ACROSS GULF OF HONDURAS TO PULSE TO 20-25 KT EACH OF THE NEXT SEVERAL NIGHTS WHERE SEAS WILL BUILD 5-7 FT...POSSIBLY TO 6-8 FT BY WED OR THU NIGHT. ACROSS THE TROPICAL N ATLC WATERS...LOW LAT ELY WAVES MOVING ACROSS THE TROPICS AND DUE S OF ATLC HIGH HELPING TO PRODUCE BROAD ZONE OF FRESH NE TO E TRADES WITH FETCH FROM 30N INTO LESSER ANTILLES. RECENT ALTIMETER PASSES AND BUOY OBS SHOW MUCH LARGER AREA OF 8 FT SEAS ACROSS THIS ZONE CURRENTLY...REACHING ALL THE WAY TO THE ISLANDS...WITH 9 FT SEAS TO BE EXPECTED. 20 KT TRADES WITH SEAS 7-8 FT EXPECTED S OF 15N...AND NEAR 15 KT AND 5-6 FT SEAS N OF 15N THROUGH THU. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS ATLC RIDGE CONTINUES WEAKLY ALONG 29N...CENTERED ON 1026 MB HIGH NEAR 29.5N51W...EXTENDING TO ABOUT 78W. STALLED FRONTAL BOUNDARY ALONG NW BORDER WILL BE DRAGGED EWD NEXT FEW DAYS WITH WEAKENING FRONT TO MEANDER ALONG ABOUT 30N BEFORE WASHING OUT BY 72 HRS ACROSS NE PORTIONS....WHILE W PORTIONS OF FRONT LIFTS N OUT OF AREA MON. LIGHT TO MODERATE ANTICYCLONIC FLOW PREVAILS ATTM PER RECENT OBS AND SCAT PASSES...WITH 15-20 KT TRADES S OF 23N AND THROUGH STRAITS OF FL. LITTLE CHANGE IN PATTERN EXPECTED THROUGH TUE...WITH WINDS NW PORTIONS GRADUALLY VEERING S TO SW TUE INTO WED AS NEXT FRONTAL SYSTEM MOVES OFF MID ATLC COAST. MODELS CONTINUE TO DIVERGE SOMEWHAT BEYOND WED WITH HANDLING OF DEEP LAYERED TROUGH MOVING ACROSS N ATLC AND ASSOCIATED SFC LOW AND FRONTAL SYSTEM. THIS WILL PRODUCE A SIGNIFICANT SWELL EVENT FOR LOCAL WATERS AND FRONTAL BOUNDARY SINKING INTO CENTRAL AND NE PORTIONS THU AND FRI. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.