000 AGXX40 KNHC 051750 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 200 PM EDT WED MAY 05 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... A WEAK STATIONARY BOUNDARY LIES OVER THE NE GULF OF MEXICO FROM 27N89W TO THE FLORIDA BIG BEND NEAR 29N83W...WITH DRIER AIR AND A WEAK HIGH ACROSS THE NW GULF. BUOY OBSERVATIONS IN THE VICINITY OF THE FRONT HAVE DIMINISHED TO 10 KT OR LESS WITH SEAS 3-4 FT. TSTM ACTIVITY HAS INCREASED S OF THE BOUNDARY OVER THE EASTERN GULF OF MEXICO ZONE DURING THE PAST FEW HOURS. THIS CONVECTION LIES IN THE DIFFLUENT REAR RIGHT QUADRANT OF A 50-70 KT UPPER JET STRETCHED ACROSS NE FLORIDA. THE JET EXIT REGION WILL SHIFT NE TONIGHT...ALLOWING TSTM ACTIVITY TO DIMINISH IN THE GULF. THE FRONT IS EXPECTED TO DISSIPATE OVER THE GULF ON THU. THE MID LEVEL SHORTWAVE TROUGH SUPPORTING THE SURFACE FRONT WILL SLOWLY DRIFT E THROUGH THU AND THEN RECEIVE A REINFORCING SHOT OF SHORTWAVE ENERGY FRI. THIS AMPLIFIED MID LEVEL TROUGHING CENTERED E OF FLORIDA WILL PREVENT THE DEEP LAYER RIDGING FROM BECOMING VERY STRONG. AS A RESULT...THE WEAK HIGH PRES SYSTEM CURRENTLY OVER THE NW GULF WILL SLOWLY MOVE INTO THE EASTERN GULF THU EVENING AND REMAIN STATIONARY THROUGH SAT. MILD WINDS AND SEAS ARE EXPECTED ACROSS THE ENTIRE BASIN TODAY THROUGH THU MORNING BEFORE SURFACE TROUGHING BEGINS TO BUILD OVER TEXAS AND NE MEXICO...INCREASING THE PRES GRADIENT OVER THE W GULF BETWEEN IT AND THE HIGH. LOOK FOR SELY RETURN FLOW ACROSS THE NW GULF TO INCREASE TO 15-20 KT AND NEAR 20 KT ALONG THE TEXAS COASTAL WATERS BY LATE THU NIGHT. AT THE SAME TIME...AN ENHANCED YUCATAN SEABREEZE WILL INCREASE WINDS TO 20 KT. YUCATAN SEABREEZE WINDS WILL CONTINUE TO FLARE TO 20 KT AT NIGHT THROUGH THE WEEKEND. A FRONTAL SYSTEM IS FORECAST BY MODELS TO DRAG ALONG THE GULF COAST SAT...BUT LOW TO MID LEVEL RIDGING SHIFTING INTO WRN GULF WILL BLOCK SRN PROGRESS OF FRONT AND ALLOW IT TO SPILL SE INTO THE NE GULF BY SAT EVENING THEN SINK S FROM NEAR THE MOUTH OF THE MISSISSIPPI RIVER TO NEAR TAMPA BAY SUN. THIS IS LIKELY TO PRODUCE A BRIEF PERIOD OF MILD NLY AND OFFSHORE FLOW OFF THE LA-MS-FL PANHANDLE COASTS EARLY SUN THROUGH MIDDAY...BUT NOT SUFFICIENT TO PROVIDE MUCH NLY PUSH FOR THE OIL WITHIN THE COASTAL ZONES THERE. SW N ATLANTIC S OF 31N W OF 55W... A 1020 MB HIGH NEAR 29N66W HAS AN ASSOCIATED RIDGE THAT EXTENDS SW TO CENTRAL CUBA WHILE A COLD FRONT HAS SLOWLY MOVED S OVER THE PAST FEW HOURS TO ST. AUGUSTINE FLORIDA. TSTMS CAN BE FOUND SE OF THE FRONT AND ARE EXPECTED TO SHIFT E AS THE DIFFLUENT REAR RIGHT QUADRANT OF THE UPPER JET MENTIONED IN THE GULF OF MEXICO SECTION PULLS NE THROUGH FAR NW WATERS HERE OVERNIGHT WITH SHOWERS CONTINUING NEAR THE FRONT THROUGH THE DAY TOMORROW AS IT WEAKENS AND MEANDERS OFF THE NE FL COAST. WINDS ASSOCIATED WITH THE FRONT ARE DIMINISHING AND ARE EXPECTED TO REMAIN UNDER 20 KT. AN OLD SHEAR LINE PERSISTS FROM THE CENTRAL ATLC SW INTO THE NRN WINDWARDS WITH NELY TRADES AROUND 20 KT AND SEAS AT 8 FT INDICATED BY SHIPS LAVY4 AND C6T2063 OVER SE WATERS...WITH THIS FLOW SPREADING SW INTO THE NE CARIBBEAN AND W ACROSS HISPANIOLA AND INTO THE TURKS AND CAICOS. SEAS NEAR THE CENTER OF THE HIGH ARE AROUND 3 FT AND GROW SLOWLY TO 4-5 FT AROUND THE PERIPHERY OF THE HIGH. THE HIGH WILL SHIFT E AND WEAKEN NEXT FEW DAYS IN RESPONSE TO THE DEEP LAYERED RIDGE BEING NUDGED EWD BY AN UPPER TROUGH BRINGING THE NEXT COLD FRONT TO THE NE GULF THU...AND THEN ERODES FURTHER INTO THE WEEKEND. THE ASSOCIATED SURFACE HIGH IS FORECAST TO WEAKEN CONSIDERABLY AS IT MOVES E...LEAVING AN ELONGATED AND NARROW RIDGE ALONG 28-30N. THIS WILL YIELD MODERATE ELY TRADES S OF 23N ACROSS THE ATLC EXTENDING W INTO THE SE BAHAMAS...WHILE WINDS AND SEAS ARE GENERALLY MILD ELSEWHERE. CARIBBEAN SEA AND TROPICAL N ATLC... THE REMNANT FRONTAL BOUNDARY OVER THE TROPICAL N ATLC AND EXTENDING INTO THE EASTERN CARIBBEAN CONTINUES TO BE A FOCUS OF SHOWER ACTIVITY IN THE REGION. 1200 UTC OBSERVATION FROM VRXL6 NEAR 16N58W SHOWED 15-20 KT WINDS AND SEAS TO 8 FT. THIS BOUNDARY IS EXPECTED TO WEAKEN AND SHIFT NW OVER THE NEXT FEW DAYS. WINDS WILL DIMINISH BELOW 20 KT LATER TODAY...BUT THE LINGERING MOISTURE WILL CONTINUE TO MAKE THIS FEATURE A FOCUS FOR SHOWERS OVER THE NE CARIBBEAN FRI AND SAT. SURFACE HIGH S OF BERMUDA WILL MERGE WITH HIGH PRES MOVING IN FROM THE N ON THU ALLOWING THE AREA OF MODERATE TRADES ALONG THE COAST OF COLOMBIA TO EXPAND THU. AS THE FRONT ACROSS THE NE GULF THIS WEEKEND SHIFTS SE OFFSHORE OF N FLORIDA BY SUN...FLOW ACROSS THE NW CARIB WILL BACK TO NELY W OF 75W. OTHERWISE...TYPICAL MODERATE TRADES AND SEAS...WITH FRESH WINDS PREVAILING ACROSS THE SRN CARIB. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING