000 AGXX40 KNHC 050825 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 324 AM 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... S/W MOVING SLOWLY E ACROSS THE SE U.S. AND NRN GULF HAS DRAGGED THE WEAK FRONTAL BOUNDARY EWD INTO THE NE GULF FROM THE BIG BEND AREA SW TO AN ELONGATED LLVL LOW NEAR 27N87W THEN SW INTO THE CENTRAL GULF...WITH DRIER AIR AND A WEAK HIGH NOW ACROSS THE NW GULF. PEAK WINDS NEAR 15 KT HAVE BEEN OCCURRING WITHIN 60-90 NM TO THE SE OF THE FRONT AND ACROSS THE SE SEMICIRCLE OF THIS LOW...WHERE OBS INDICATE SEAS 3-4 FT. A LLVL TROUGH ASSOCIATED WITH THE DIURNAL SEABREEZE DEVELOPMENT ACROSS THE YUCATAN EXTENDS N TO NEAR THE SW TAIL OF THE FRONT...WITH WINDS ALONG THE NE AND W COAST OF THE YUCATAN GRADUALLY DIMINISHING OVERNIGHT TO NEAR 15 KT ATTM. THE ELONGATED LOW INTERACTING WITH THE MOISTURE DAMMED ALONG THE BACK SIDE OF THE FRONT IS YIELDING SCATTERED STRATIFORM PRECIP ACROSS THE N CENTRAL GULF...WHILE UPPER DYNAMICS TO THE E OF THE ASSOCIATED UPPER TROUGH ARE YIELDING SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE NE GULF AND N FL SE OF THE FRONT. SCATTERED LOW TOPPED SHOWERS WERE ALSO OCCURRING ACROSS THE SW GULF OFF THE W COAST OF THE YUCATAN IN GOOD LLVL CONVERGENCE. UPPER SUPPORT FOR THIS FRONT WILL LIFT OUT TO THE NE NEXT 48 HRS AND LEAVE THE WEAK BOUNDARY STRUNG OUT NE TO SW FROM THE NE GULF TO NEAR 26N90W WED BEFORE WEAK LLVL RIDGING SHIFTS W THROUGH THE STRAITS OF FLORIDA AND INTO THE SE GULF...AND LIFTS TO FRONTAL REMNANTS N TO ALONG ABOUT 28N THU. LLVL FLOW WILL BECOME PARALLEL TO FRONT BY THU EVENING AND BOUNDARY WILL THEN LOSE ITS IDENTITY. MILD WINDS AND SEAS ARE EXPECTED ACROSS THE ENTIRE BASIN TODAY THROUGH THU MORNING BEFORE THIS HIGH SHIFTING INTO THE SE GULF OPENS UP AND PRODUCES A SLY RETURN FLOW ACROSS THE NW GULF 15-20 KT AND NEAR 20 KT ALONG THE TEXAS COASTAL WATERS...AS WELL AS AN ENHANCED YUCATAN SEABREEZE AROUND 20 KT. FRONTAL SYSTEMS MOVING THROUGH THE CENTRAL U.S. AT THAT TIME FORECAST BY MODELS TO DRAG ALONG THE GULF COASTS 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 STAINED COASTAL ZONES THERE. SW N ATLANTIC S OF 31N W OF 55W... A 1020 MB HIGH HAS JUST SHIFTED E ACROSS BUOY 41049 PAST FEW HOURS WITH ASSOCIATED RIDGE EXTENDING W-NW TO COLD FRONT OFF OF GA AND SC COASTS...WHERE SCATTERED SHOWERS AND TSTMS CONTINUED TO IGNITE E OF THE FRONT. ANTICYCLONIC FLOW ASSOCIATED WITH THIS DEEP LAYERED RIDGE GENERALLY DOMINATES THE REGION. ON THE WRN PERIPHERY OF THE HIGH 15 KT SLY FLOW WAS INDICATED BY OBS E OF THE FRONT EXTENDING INTO THE NW BAHAMAS. AN OLD SHEAR LINE PERSISTS FROM THE CENTRAL ATLC SW INTO THE NRN WINDWARDS WITH NELY TRADES AROUND 20 KT INDICATED BY AN 0142 UTC ASCAT PASS... WITH THIS FLOW SPREADING SW INTO THE NE CARIBBEAN AND W ACROSS HISPANIOLA AND INTO THE SE BAHAMAS. STRONG SUBSIDENCE AND DRIER BACKDOOR AIR BEHIND THE SHEAR LINE HAVE MOVED INTO THE EXTREME NE CARIB AND ADJACENT ATLC TO CLEAR OUT RECENT CLOUDS AND SHOWERS AND BRING VERY DRY AND COMFORTABLE AIR TO THE REGION. SEAS NEAR THE CENTER OF THE HIGH ARE AROUND 3 FT AND GROW SLOWLY TO 4-5 FT AROUND THE PERIPHERY OF THE HIGH...EXCEPT JUST OUTSIDE THE N AND E CARIB ISLANDS WHERE THE EXITING WIND SURGE N OF THE SHEARLINE HAS BUILT SEAS TO 6-7 FT PAST 24 HOURS BUT ARE NOW BEGINNING TO SUBSIDE VERY SLOWLY. 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... AS INDICATED ABOVE...SURFACE HIGH S OF BERMUDA ALREADY BEGINNING TO SLIDE SLOWLY E AND HAS BEGUN TO RELAX PRES GRADIENT ACROSS THE WRN CARIB. AN 0140 UTC ASCAT PASS AND AVAILABLE OBS INDICATE MODERATE NELY TRADES ACROSS THE NE CARIB N OF THE SHEAR LINE...AND MODERATE TO FRESH ACROSS THE CENTRAL CARIB...WITH WINDS 20-25 SUGGESTED OFF THE COAST OF COLOMBIA...AND 15 KT OR LESS W OF 80W. SEAS GENERALLY 5-6 FT ACROSS THE OPEN CARIB E OF 80W EXCEPT 7-8 FT OFF COAST OF COLOMBIA. LITTLE CHANGE EXPECTED THROUGH THU...WHEN NEW HIGH DEVELOPS ACROSS THE SE GULF AND TIGHTENS GRADIENT ACROSS THE S AND CENTRAL CARIB W OF 65W. 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