000 AGXX40 KNHC 040731 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 331 AM EDT FRI APR 4 2014 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: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST WHICH IS A GFS/ECMWF BLEND. LATEST MWW3 BLENDED WITH PREVIOUS/OFFICIAL FORECAST EXCEPT NWPS USED WHERE AVAILABLE. MEDIUM-HIGH CONFIDENCE. OBSERVATIONS IN THE NW AND N CENTRAL OFFSHORE AND COASTAL WATERS STILL INDICATE PATCHY FOG OCCASIONALLY REDUCING VISIBILITIES DOWN TO AROUND 1 NM. FOG SHOULD DIMINISH BY LATE THIS MORNING AS A COLD FRONT APPROACHES THE TEXAS COAST. 1022 MB ATLC HIGH PRES NEAR 28N70W EXTENDS A RIDGE ACROSS FL TO ACROSS THE U.S. GULF COAST ALONG 30N. MODERATE TO FRESH RETURN FLOW DOMINATES THE BASIN...EXCEPT FOR FRESH TO STRONG JUST NW-N OF THE YUCATAN PENINSULA AS INDICATED BY RECENT ASCAT SCATTEROMETER PASSES. SEAS ARE 4-7 FT...EXCEPT 2-4 FT IN THE FAR E GULF (SEAS 5-7 FT STRAITS OF FLORIDA VIA SHIP OBSERVATIONS). MODEL GUIDANCE CONTINUES TO BRING A COLD FRONT INTO THE GULF LATER THIS MORNING... STALLING AS IT REACHES FROM THE WESTERN FL PANHANDLE TO JUST S OF BROWNSVILLE TEXAS TONIGHT. THE FRONT WILL THEN RETREAT BACK TO THE NW AS A WARM FRONT SAT AFTERNOON TROUGH SUN AFTERNOON. LOW PRES DEVELOPS NEAR THE TEXAS COAST OR OVER THE TEXAS COASTAL WATERS SUN EVENING QUICKLY SHOOTING OFF TO THE NE OVER THE MS VALLEY WHILE RAPIDLY DEEPENING. THIS LOW WILL DRAG THE FRONT ACROSS THE GULF WATERS AS A COLD FRONT REACHING FROM NEAR BILOXI MS TO THE CENTRAL BAY TO NEAR TAMPICO MX MON MORNING...THEN FROM NEAR TAMPA BAY FL TO THE N CENTRAL YUCATAN PENINSULA TUE MORNING...EXITING THE GULF TUE EVENING. WINDS INCREASE TO FRESH TO STRONG AHEAD OF THE FRONT IN SOUTHERLY FLOW SUN NIGHT WITH SEAS BUILDING UP TO 8 FT IN THE CENTRAL GULF. THIS FRONT IS UNUSUALLY STRONG BY APRIL STANDARDS WITH BOTH THE GFS AND ECMWF INDICATING WINDS TO AT LEAST 30 KT IN THE N CENTRAL AND NE GULF TUE NIGHT INTO WED AS A REINFORCING SURGE OF COLD AIR ARRIVES AFTER THE FRONT CLEARS THE GULF. THE UKMET IS SLIGHTLY WEAKER WITH PEAK WINDS AROUND 25 KT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 65W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST WHICH IS A GFS/ECMWF BLEND. LATEST MWW3 BLENDED WITH PREVIOUS/OFFICIAL FORECAST EXCEPT NWPS USED WHERE AVAILABLE. MEDIUM-HIGH CONFIDENCE. A SHEAR LINE...THE REMNANTS OF AN OLD COLD FRONT...EXTENDS FROM THE ANEGADA PASSAGE TO NEAR 17N68W WITH 15-20 KT WINDS TO THE N AND 10-15 KT WINDS TO THE S. THIS SHEAR LINE WILL DISSIPATE DURING THE NEXT 24 HOURS. ATLC HIGH PRES NEAR 28N70W IS MOVING SLOWLY EASTWARD AND COMBINED WITH NORTHERN COLOMBIA LOW PRES IS SUPPORTING FRESH TO STRONG TRADES IN THE S CENTRAL CARIBBEAN...UP TO AROUND 30 KT NEAR THE IMMEDIATE COAST OF COLOMBIA AS CAPTURED BY A 0152 UTC ASCAT SCATTEROMETER PASS...WITH SEAS AT 8-11 FT. RECENT ASCAT PASSES ALSO SHOWED FRESH TO STRONG WINDS IN AND DOWNWIND OF THE WINDWARD PASSAGE (ONCE AGAIN NOT FORECAST BY PREVIOUS MODEL RUNS)...WITH FRESH TO STRONG E-SE WINDS IN THE GULF OF HONDURAS. MEANWHILE MODERATE TO LOCALLY FRESH TRADES DOMINATE ELSEWHERE IN THE CARIBBEAN...ALONG WITH 4-7 FT SEAS. THE GULF OF HONDURAS WINDS WILL CONTINUE TO PULSE TO FRESH TO STRONG LEVELS...DIMINISHING TO MODERATE TO FRESH DURING THE AFTERNOON HOURS...WHILE FRESH TO STRONG TRADES PERSIST IN THE S CENTRAL CARIBBEAN THROUGH SAT MORNING. THE PRES GRADIENT WILL TIGHTEN SAT NIGHT WITH THE AREA OF FRESH TO STRONG TRADES EXPANDING TO ALL OF THE CENTRAL CARIBBEAN AND ALSO ACROSS THE E CARIBBEAN WATERS. THESE CONDITIONS WILL THEN PERSIST SUN THROUGH MON NIGHT WHILE THE GULF OF HONDURAS WINDS PEAK AT 30 KT SUN NIGHT THROUGH MON MORNING. AN UNUSUALLY STRONG COLD FRONT WILL ENTER THE NW CARIBBEAN PASSING THROUGH THE YUCATAN CHANNEL TUE AFTERNOON INTO EVENING WITH WINDS IN THE GULF OF HONDURAS DIMINISHING AS IT APPROACHES. THIS IMPRESSIVE FRONT WILL EXTEND FROM CENTRAL CUBA TO CENTRAL HONDURAS BY WED MORNING WITH AT LEAST FRESH TO STRONG WINDS BEHIND IT IN AMZ011 AND AMZ017. IN THE TROPICAL N ATLC...A SHEAR LINE EXTENDS FROM NEAR 20N55W TO THE ANEGADA PASSAGE WITH MODERATE TO FRESH NE WINDS TO THE N AND MODERATE WINDS TO THE S. MEANWHILE SEAS ARE 4-7 FT ACROSS THE WATERS. THE SHEAR LINE WILL WASH OUT DURING THE NEXT 24 HOURS WHILE SINKING SLIGHTLY TO THE S. WINDS WILL INCREASE TO FRESH TO STRONG ACROSS THE TROPICAL N ATLC SAT NIGHT THROUGH THE REMAINDER OF THE FORECAST PERIOD AS THE PRES GRADIENT TIGHTENS ACROSS THE REGION. SEAS WILL BUILD TO 5-8 FT AS THE WINDS INCREASE. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST WHICH IS A GFS/ECMWF BLEND. LATEST MWW3 BLENDED WITH PREVIOUS/OFFICIAL FORECAST EXCEPT NWPS USED WHERE AVAILABLE. MEDIUM-HIGH CONFIDENCE. 1022 MB HIGH PRES DOMINATES THE BASIN LOCATED NEAR 28N70W. LIGHT TO MODERATE ANTICYCLONIC WINDS ARE ACROSS THE WATERS N OF 22N WITH MAINLY FRESH WINDS S OF 22N...STRONGEST NEAR THE WINDWARD PASSAGE. SEAS ARE 4-7 FT IN THE SE HALF OF THE BASIN...AND 3-5 FT IN THE NW HALF...EXCEPT 1-3 FT INSIDE THE BAHAMAS. THE HIGH WILL SHIFT SLOWLY E-SE THROUGH SAT WHEN IT WILL REACH 65W...THEN SHIFT E OF 65W BY EARLY SUN. MODERATE TO FRESH RETURN FLOW SPREADS ACROSS THE WHOLE BASIN SUN AS THE HIGH SHIFTS EASTWARD. A COLD FRONT WILL APPROACH THE NW CORNER FROM THE SE GA/NE FL COASTAL WATERS SAT STALLING ACROSS EXTREME NW PORTIONS BY SUN MORNING THEN RETREATING TO THE NW AS A WARM FRONT THROUGH SUN NIGHT AS ATLC RIDGING REBUILDS. THE FRONT MOVES BACK INTO THE NW PORTION BY TUE MORNING WITH FRESH TO STRONG WINDS N OF 27N AHEAD OF IT. THIS STRONG COLD FRONT WILL REACH FROM 31N71W TO THE CENTRAL BAHAMAS BY WED MORNING WITH MODERATE TO FRESH W-NW WINDS BEHIND IT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 LEWITSKY. NATIONAL HURRICANE CENTER.