000 AGXX40 KNHC 060842 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 340 AM EDT THU MAY 06 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 AND DETERIORATING FRONTAL BOUNDARY REMAINS NEARLY STATIONARY FROM THE CENTRAL GULF NEAR 25.5N90W NE ACROSS THE FLORIDA BIG BEND AND ACROSS THE FAR SE CORNER OF GA AND NE INTO THE W ATLC. A WWD MOVING LLVL TROUGH HAS MOVED OFF THE YUCATAN PENINSULA AND WAS ALONG 90/91W EXTENDING NEARLY TO THE SW TAIL OF THE FRONTAL BOUNDARY. LLVL ANTICYCLONIC FLOW TO THE E OF THESE FEATURES DOMINATED THE SE GULF WHILE A BROADER RIDGE NOSED FROM S OF THE MOUTH OF THE MIGHTY MISSISSIPPI SW TO THE UPPER MEXICAN COAST. WINDS ACROSS THE GULF WERE GENERALLY 10 KT OR LESS EXCEPT FOR SMALL AREAS NEAR 15 KT JUST W OF THE TROUGH OFF THE YUCATAN AND ACROSS THE FAR WRN GULF BETWEEN TAMPICO AND CORPUS CHRISTI...WHERE PEAK SEAS WHERE 3-4 FT. THE FRONTAL BOUNDARY IS EXPECTED TO BECOME NEARLY DIFFUSE OVER THE NE GULF DURING THE NEXT 24 HOURS...HOWEVER MODELS HANG ON TO SOME VERY WEAK TROFFING AND MODEST MOISTURE CONVERGENCE THROUGH FRI MORNING. THE MID LEVEL SHORTWAVE TROUGH SUPPORTING THE SURFACE FRONT HAS SHIFTED E OVER THE FLORIDA PENINSULA WITH A NEXT REINFORCING SHOT OF SHORTWAVE ENERGY FORECAST FOR LATE TONIGHT. THIS AMPLIFIED MID LEVEL TROUGHING CENTERED E OF FLORIDA WILL PREVENT THE DEEP LAYER RIDGING FROM BECOMING VERY STRONG. AS A RESULT...THE WEAK RIDGING CURRENTLY OVER THE NW GULF WILL SLOWLY WEAKEN TONIGHT AS IT SHIFTS E-NE ALLOWING THE WEAK HIGH OFF THE SW COAST OF FLORIDA TO BECOME THE DOMINANT HIGH. MILD WINDS AND SEAS ARE EXPECTED ACROSS THE ENTIRE BASIN THROUGH THIS AFTERNOON BEFORE SURFACE TROUGHING BEGINS TO BUILD OVER W TEXAS AND NE MEXICO...INCREASING THE PRES GRADIENT OVER THE W AND SW 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 TONIGHT. 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 STILL 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 DRAPE OVER THE RIDGE AND SPILL SE INTO THE NE GULF SAT NIGHT THEN SINK S FROM NEAR THE MOUTH OF THE MISSISSIPPI RIVER TO NEAR TAMPA BAY SUN EVENING. MODELS REMAIN CONSISTENT IN THIS SCENARIO BUT HAVE SLOWED PROGRESS OF THIS FRONT BY ABOUT 6-8 HOURS SINCE YDA. THIS IS LIKELY TO PRODUCE A BRIEF PERIOD OF LIGHT TO MODERATE NLY AND OFFSHORE FLOW OFF THE LA-MS-FL PANHANDLE COASTS SAT THROUGH LATE SUN MORNING BEFORE VEERING ELY SUN AFTERNOON. HOWEVER THIS FLOW WILL LIKELY NOT BE 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 REMAINS NEAR 28.5N63W AND HAS AN ASSOCIATED RIDGE THAT EXTENDS SW THROUGH THE STRAITS OF FLORIDA. A COLD FRONT ACROSS N FLORIDA HAS DRIFTED NE OVERNIGHT TO SE GA. SCATTERED SHOWERS AND ISOLATED TSTMS WILL CONTINUE E AND REMOVED FROM THE FRONT THROUGHOUT THE DAY...OCCURRING E OF THE MID-UPPER LEVEL S/W AXIS JUST OFF SHORE OF FLORIDA AND N OF 27N. THE WEAK HIGH PRES RIDGE ACROSS THE SW ATLC IS YIELDING LIGHT TO MODERATE WINDS ACROSS THIS PORTION OF THE BASIN AT 5 TO 15 KT...WITH 15 KT FLOW OCCURRING AROUND THE PERIPHERY OF THE RIDGE INVOF THE NE CARIBBEAN. AN OLD SHEAR LINE PERSISTS FROM THE CENTRAL ATLC SW ACROSS THE NRN WINDWARDS AND INTO THE SE CARIB WITH NELY TRADES AROUND 15 KT AND SEAS AT 6 FT N OF THE SHEARLINE AND E OF THE ISLANDS. THIS 15 KT FLOW ALSO SPREADS SW INTO THE NE CARIBBEAN AND W ACROSS HISPANIOLA AND INTO THE TURKS AND CAICOS. SEAS NEAR THE CENTER OF THE HIGH ARE 2-3 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 THE UPPER TROUGH MOVING E OFF FLORIDA. THE ASSOCIATED SURFACE HIGH IS FORECAST TO WEAKEN CONSIDERABLY AS IT MOVES E...LEAVING AN ELONGATED AND NARROW RIDGE ALONG 26/27N. 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 SHEARLINE OVER THE TROPICAL N ATLC AND EXTENDING SW INTO THE EASTERN CARIBBEAN CONTINUES TO BE A MAIN FOCUS OF SHOWER ACTIVITY ACROSS THE REGION...WITH SCATTERED TO LOCALLY NUMEROUS SHOWERS AND VERY ISOLATED TSTMS CURRENTLY INDICATED BY STLT IMAGERY. RECENT ASCAT PASSES SHOWED NELY FLOW 15-20 KT WITHIN 150 NM N OF THIS SHEARLINE. THIS BOUNDARY IS EXPECTED TO WEAKEN AND SHIFT W OVER THE NEXT FEW DAYS. LINGERING MOISTURE WILL CONTINUE TO MAKE THIS FEATURE A FOCUS FOR SHOWERS OVER THE E AND NE CARIBBEAN FRI AND SAT. THIS 15-20 KT NELY FLOW EXTENDED SW TO THE CENTRAL CARIBBEAN AND MERGED WITH THE CLIMATOLOGICAL ZONE OF 20-25 KT WINDS OFF THE COLOMBIAN COAST WHERE SEAS WERE REPORTED AT 8 FT BY SHIP DFRZ. AS THE SURFACE HIGH DEVELOPS OVER THE SE GULF TONIGHT THE PRES GRADIENT WILL TIGHTEN ACROSS THE CENTRAL AND SW GULF AND THE 20 KT WIND FIELD WILL EXPAND BRIEFLY INTO THE SW GULF BEFORE THIS HIGH LIFTS N INTO THE NE GULF FRI AND COLLAPSES. THE RIDGING ALONG 26/27N OVER THE WEEKEND WILL MAINTAIN SUFFICIENT GRADIENT ALONG THE SRN CARIB TO PRODUCE 20 KT TRADES FROM THE ISLA MARGARITA AREA OFF VENEZUELA W TO 80W...AND 25+ KT FLOW OFF OF COLOMBIA...WHERE SEAS WILL LIKELY BUILD TO A PEAK NEAR 10 FT. OTHERWISE...TYPICAL MODERATE TRADES AND SEAS FOR MAY WILL PREVAIL ACROSS THE REMAINDER OF THE CARIB. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING