000 AGXX40 KNHC 180730 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 230 AM EDT WED MAR 18 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... STATIONARY FRONT EXETNDS FROM NEAR FORT MYERS FLORIDA TO WEAK 1016 MB LOW PRES NEAR 26N87W TO 24N90W. AN ASCAT PASS FROM 01Z SHOWED MAINLY 10 TO 15 KT NE WINDS OVER MUCH OF THE AREA...ALTHOUGH SMALL AREAS OF 20 KT WINDS ARE NOTED JUST NORTH OF THE LOW. THE FRONT WILL DISSIPATE LATER TODAY OVER THE SE GULF. A SHORT WAVE TROUGH IS PUSHING THROUGH THE CENTRAL PLAINS CURRENTLY...AND WILL PUSH THROUGH THE GULF LATE TODAY AND TONIGHT...MAINTAINING A WEAK SURFACE TROUGH OVER THE MIDDLE GULF INTO THU. THIS WILL KEEP MODERATE EAST WINDS OVER THE NORTHERN GULF OVERNIGHT...WITH GENERALLY LIGHT FLOW ELSEWHERE. LOOKING AHEAD TO FRIDAY AND THE WEEKEND...A DEEP LAYER TROUGH CURRENTLY MOVING INTO THE GREAT LAKES BECOMES MORE AMPLIFIED OVER THE U.S. EAST COAST ON FRIDAY. THIS PUSHES A FRONT ACROSS THE SOUTHEASTERN U.S. AND INTO FLORIDA...JUST CLIPPING THE EASTERN GULF WATERS FRI INTO SAT. WITH THE BULK OF THE UPPER ENERGY MOVING INTO THE CENTRAL ATLC...THE FRONT DISSIPATES AS IT MOVES SOUTH THROUGH FLORIDA AND THE EASTERN GULF. STRONG SURFACE HIGH PRES BUILDS OVER THE CAROLINAS BEHIND THE FRONT SAT INTO SUN...DELIVERING FRESH TO STRONG EASTERLY WINDS OVER MOST OF THE GULF FROM FRI NIGHT THROUGH SUN. CARIBBEAN... HIGH RESOLUTION DATA FROM A 23Z QUIKSCAT PASS INDICATED 15 TO 20 KT FLOW OVER MUCH OF THE SOUTH CENTRAL CARIBBEAN...WITH WINDS TO 25 KT PERSISTING OFF THE COLOMBIAN COAST. THIS FLOW WILL CONTINUE TO DIMINISH TODAY AS HIGH PRES THAT WAS JUST EAST OF THE BAHAMAS WEAKENS AND SHIFTS FURTHER EAST AHEAD OF A DEEP LAYER TROUGH AND COLD FRONT MOVING THROUGH THE EASTERN U.S. AND WESTERN ATLC. THIS INDUCED A BRIEF PERIOD OF 15 TO 20 KT FLOW FROM THE NORTHERN LEEWARDS TO SOUTH OF PUERTO RICO...AS NOTED IN THE SAME QUIKSCAT PASS. HIGH PRES BUILDS BETWEEN THE CAROLINAS AND BERMUDA THU AND FRI...MAINTAINING MODERATE TO FRESH WINDS OVER THE EASTERN CARIBBEAN THROUGH THE WEEKEND. A SECOND MID/UPPER TROUGH PUSHES THROUGH THE EASTERN U.S. BY FRI...FOLLOWED BY STRONG SURFACE HIGH PRES BUILDING INTO THE GULF OF MEXICO. THIS WILL INCREASE THE PRESSURE GRADIENT OVER THE CARIBBEAN AND INCREASE WINDS ONCE AGAIN OVER 20 KT OVER MUCH OF THE WESTERN CARIBBEAN. ATLANTIC S OF 31N W OF 55W... A COLD FRONT EXTENDS FROM A DEEPENING 1004 MB SURFACE LOW NEAR 35W64W TO NEAR BERMUDA TO THE NORTHERN BAHAMAS. BUOY 41048 NEAR 32N70W REPORTED BRIEF 30 TO 35 KT NW TO N FLOW EARLIER THIS EVENING...ALTHOUGH A 23Z QUIKSCAT PASS AND REPORTS FROM BUOY 44004...ADRIFT NEAR 30N70W...INDICATE THAT 20 TO 25 KT WINDS PREVAIL S OF 31N TO 28N E OF 75W. ALSO OF NOTE IS THE REPORT FROM BUOY 41048 MOORED JUST TO THE NORTH OF 44004 32N70W INDICATING SEAS TO 17 FT DUE TO STRONG PERSISTENT WINDS AND THE ARRIVAL OF NORTHERLY LARGE LONG PERIOD SWELL. THIS IS SLIGHTLY HIGHER THAN REPORTED BY WAVEWATCH FOR THIS TIME. THROUGH THU...THE SURFACE LOW MOVES FURTHER EAST...AS HIGH PRES BUILDS OFF THE EASTERN SEABOARD. FRESH TO STRONG NORTH WINDS DIMINISH OVER THE WATERS BETWEEN N FLORIDA AND BERMUDA...BUT THE NORTHERLY SWELL CONTINUES TO PUSH INTO THE AREA. MOST OF THE 10 TO 15 FT SWELL MISSES THE ISLANDS AND WILL STAY MAINLY N OF 25N E OF 70W...LEAVING SWELL TO 8 FT ENVELOPING THE AREA. LOOKING AHEAD TO THE WEEKEND...THE NEXT MAJOR LONG WAVE TROUGH PUSHES INTO THE EASTERN U.S. WITH A STRONG SW JET ALOFT AHEAD OF THE TROUGH. DIVERGENT FLOW ALOFT ON THE RIGHT REAR OF THE JET WILL SUPPORT DEVELOPMENT OF A WEAK SURFACE TROUGH JUST EAST OF THE BAHAMAS. AS THE UPPER TROUGH AMPLIFIES NORTH OF THE AREA...THE NEXT COLD FRONT MOVES OFF THE N FLORIDA COAST THU NIGHT. MODEL GUIDANCE SUGGESTS THE TROUGH MORPHING INTO A WEAK SURFACE LOW ALONG THE FRONTAL BOUNDARY AND LIFTING OUT TOWARD BERMUDA...BUT THEY DIFFER ON THE TIMING...WITH THE CONSENSUS MOVING THE LOW NORTHWARD TO BERMUDA BY EARLY SAT. THE TRAILING TROUGH EXTENDS FROM THE LOW PRES NEAR BERMUDA TO THE SOUTHERN BAHAMAS BY FRI NIGHT...AND FROM 31N60W TO NEAR THE MONA PASSAGE BY LATE SAT. THE DEVELOPMENT OF THE LOW ALONG THE FRONT WILL TIGHTEN THE PRESSURE GRADIENT BETWEEN THE LOW AND HIGH PRES BUILDING BEHIND THE FRONT OVER THE EASTERN U.S. THIS IN TURN WILL RESULT IN A BROAD AREA OF STRONG NE WINDS...PERHAPS AS HIGH AS 30 KT...BEHIND THE FRONT BY LATE SAT. ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER CHRISTENSEN. TROPICAL PREDICTION CENTER.