000 AGXX40 KNHC 110803 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 402 AM EDT TUE SEP 11 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... FRONTAL BOUNDARY HAS BECOME NEARLY STATIONARY ACROSS THE NRN GULF ALONG ABOUT 27N...WITH ISOLATED DEEP CNVTN CONTINUING TO FIRE ALONG BOUNDARY ACROSS NW PORTIONS....WHERE LINGERING UPPER TROUGHING IS PROVIDING SUPPORT. STLT IMAGERY THIS MORNING SUGGESTS LLVL CYCLONIC TURNING ABOUT A PRE FRONTAL TROUGH ACROSS THE SW N ATLC...EXTENDING WWD ACROSS CENTRAL FLORIDA AND INTO THE FAR E GULF. THIS COUPLED WITH MID LEVEL CONVERGENCE ACROSS THE ERN GULF WILL HELP THE FRONTAL BOUNDARY TO BECOME DIFFUSE ACROSS NE PORTIONS OF BASIN...WHILE LLVL CONVERGENCE ACROSS NW PORTIONS OF BASIN WILL CONTINUE TO YIELD SCATTERED SHOWERS AND ISOLATED TSTMS THROUGH THIS EVENING...BEFORE SHIFTING NW AND INLAND ALONG THE TEXAS COAST TONIGHT. LLVL WIND SURGE INDUCED BY BUILDING HIGH PRES BEHIND FRONT LOOKS TO BE NUDGING INTO FAR NE GULF ATTM...WITH CU LINE MOVING W OFF THE COAST LIKELY THE LEADING EDGE OF 15-20 KT ENE WINDS. THIS SURGE AND ASSOCIATED LLVL CONVERGENCE EXPECTED TO YIELD MODERATE CNVTN ACROSS NE PORTIONS TODAY. FRONTAL REMNANTS ACROSS E PORTIONS ARE SUGGESTED TO BE FORCED SWD TO NEAR 25.5N BY THU MORNING BY BUILDING HIGH TO THE N AND ASSOCIATED ELY FLOW OF 15-20 KT SHOULD BUILD ACROSS MOST OF E HALF OF BASIN BY THAT TIME....WITH SEAS 4-6 FT. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... AS MENTIONED ABOVE...FRONTAL BOUNDARY SOMEWHAT ILL DEFINED WITH BROAD CYCLONIC TURNING OCCURRING TO THE S AND SE OF BOUNDARY AND DEPICTED AS PRE FRONTAL TROUGH ON 06Z SFC MAP. SCATTERED SHOWERS AND ISOLATED TSTMS TO PERSIST ALONG FRONTAL BOUNDARY AND WITHIN PRE FRONTAL TROUGHING TODAY UNDER A MOIST AND NICELY SHEARED ENVIRONMENT. FRONT ESTIMATED ALONG N EDGE OF CNVTN AND ACROSS CENTRAL FLORIDA...WHICH IS A BIT N OF RECENT SFC MAPS. FRONT TO SINK SLOWLY SSE TODAY AND TONIGHT...BECOMING STATIONARY ACROSS NW BAHAMAS AND S FLORIDA ALONG ABOUT 26N BEFORE WEAKENING INTO A SHEAR LINE WED. NELY FLOW 15-20 KT WILL BUILD IN ACROSS THE WATERS BEHIND FRONT TODAY...WITH STRONGEST WINDS AROUND 20 KT WITHIN 90 NM N OF FRONT...WITH BUILDING NELY WIND WAVES MIXING WITH FADING NE SWELL FROM LESLIE AND MAINTAINING SEAS AROUND 5 FT EXCEPT 6-7 WITHIN THE AREAS OF 20 KT WINDS. FRONTAL BOUNDARY TO BECOME STATIONARY TONIGHT FROM NEAR 31N60W TO FLL AREA WITH BUILDING HIGH INCREASING PRES GRADIENT AND YIELDING BROAD ZONE OF NE TO E WINDS 20 TO LOCALLY 25 KT ACROSS WATERS NW OF FRONT WED...AND SEAS BUILDING 6-8 FT. FORECAST SOMEWHAT UNCERTAIN AFTER THU AS UPPER TROUGH MOVING INTO NW ATLC INTERACTS WITH CURRENT TUTT SEGMENT FROM CENTRAL ATLC TO JUST E OF THE LESSER ANTILLES...AND IS RESULTANT INFLUENCE ON INTENSITY AND TRAJECTORY OF TROPICAL LOW ACROSS CENTRAL ATLC. VARIOUS SOLUTIONS OF A SFC LOW DEVELOPING ALONG FRONTAL REMNANTS OR JUST E WITHIN THE PRE FRONTAL TROUGH ARE DEPICTED BY ALL THE MODELS...WITH A WIDE RANGE IN SOLUTIONS. WILL WAIT FOR CLEARER SIGNALS FROM GUIDANCE. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... EXCEPT FOR FRESH TRADES ACROSS THE S CENTRAL CARIB...CONDITIONS SEASONABLY TRANQUIL ACROSS THE BASIN THIS MORNING. REMNANTS OF A TROPICAL WAVE THAT PRECEDED THE LOW/WAVE ALONG 42W WAS MOVING ACROSS 50W THIS MORNING AND WILL SHIFT W TO NEAR 55W TONIGHT THROUGH WED AND INTERACT WITH TUTT FOR ISOLATED DEEP CNVTN. OTHERWISE...MODERATE TRADES TO CONTINUE ACROSS THE CARIB... EXCEPT FOR S CENTRAL PORTIONS W...WHILE LIGHT TO MODERATE NELY WINDS PREVAIL ACROSS THE TROPICAL N ATLC WATERS. AS FOR LOW/TROPICAL WAVE ALONG 42W...STLT AND MICROWAVE IMAGERY...AS WELL AS A RECENT 0230Z OSCAT PASS SUGGEST THAT A SMALL AND TIGHT LOW TO MID LEVEL CIRCULATION HAS DEVELOPED ALONG THE WAVE...AND ANY INCREASED CONVECTIVE BANDING TODAY WILL LIKELY REQUIRE T.D. OR T.S. CLASSIFICATION OF THIS SYSTEM. A WNW MOTION IS EXPECTED OVER THE NEXT 12-18 HOURS BEFORE THIS SYSTEM BEGINS TO FEEL THE INFLUENCE OF THE TUTT LOCATED E OF THE ISLANDS...AND BE GUIDED MORE NW. GFS MODEL HAS BEEN ON LEFT SIDE OF GLOBAL MODELS AND WE HAVE BLENDED GRIDS TO ATTEMPT TO REFLECT THIS. MODEL CONSENSUS DOES NOT ALLOW LOW TO REACH 55W BEFORE TURNING N INTO THE OPEN CENTRAL ATLC. BROAD WIND FIELD ACROSS N AND NE SEMICIRCLES WILL YIELD SIZEABLE AREA OF 20-25 KT WINDS AND SEAS 8-12 FT BY 48 HOURS. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING