000 AGXX40 KNHC 301610 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1210 PM FRI JUL 28 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. AN UPPER CYCLONE IS CUT OFF OVER THE N-CENTRAL GULF OF MEXICO NEAR 27N93W AND IS MOVING W WITH TIME. ANOTHER UPPER CYCLONE HAS MOVED W AND INLAND OLD MEXICO NEAR 25N100W AND CONTINUES TO FILL WITH TIME. AN UPPER ANTICYCLONE HAS BECOME ELONGATED ALONG 31N BETWEEN 86W AND 78W WITH ITS MEAN CENTER NEAR 31N82W ATTM. AN UPPER ANTICYCLONE APPEARS STATIONARY OVER THE BAY OF CAMPECHE AT 19N93W. THUS...THE UPPER FLOW IS COMPLICATED OVER THE GULF OF MEXICO BUT ISOLATED CONVECTION IS GENERALLY ENHANCED N OF 25N...AND ALSO S OF 25N W OF 90W. ANOTHER UPPER CYCLONE HAS CUT OFF AS EXPECTED OVER THE W ATLC AT 26N74W WITH AN UPPER TROUGH EXTENDING S TO A BROAD BASE ALONG 18N BETWEEN 85W AND 76W. AN UPPER ANTICYCLONE...CURRENTLY OVER PUERTO RICO...HAS BECOME DOMINATE WITH ITS ENVELOPE OF ANTICYCLONIC FLOW NOW DOMINATING MOST THE ATLC PORTION OF THE DISCUSSION AREA. THE EXCEPTION IS A SHORTWAVE TROUGH HAS DIPPED SE INTO THE SUBTROPICAL ATLC ROUGHLY ALONG 31N48W TO 25N55W. AN ASSOCIATED SURFACE FRONT WILL MOVE TO JUST E OF THE EXTREME NE WATERS IN ABOUT 42 HOURS AND THUS MENTION OF SLY WINDS TO 20 KT SEAS TO 8 FT ADDED TO THIS MORNINGS PACKAGE...WITH AN IMPACT THROUGH AT LEAST 48 HOURS...BUT SHIFTING E OF THIS DISCUSSION AREA BY SUNSET MON. ADDITIONALLY A TUTT EXTENDS INTO THE AREA ALONG 16N55W TO NEAR 9N62W. THE GFS AND NOGAPS BOTH AGREE THAT THE UPPER CYCLONE NEAR THE BAHAMAS WILL SHIFT GENERALLY NW ACROSS S-CENTRAL FL THROUGH THE MIDDLE OF THE WEEK. FORECAST PSN DIFFER THEREAFTER WITH GFS NEAR FL BIG BEND LATE FRI WHILE NOGAPS CENTERS CYCLONE OVER SE LA...STILL PRETTY GOOD AGREEMENT CONSIDERING THAT IS LATE IN DAY 5. BOTH MODELS ALSO AGREE ON THE UPPER ANTICYCLONE SHIFTING N TO NEAR CAPE HATTERAS BY LATE FRI ALLOWING AN UPPER CYCLONE TO CUT OFF FROM THE CENTRAL ATLC TUTT AND SHIFT W TO JUST N OF PUERTO RICO BY LATE WEEK. AT THE LOW LEVELS...THE SUBTROPICAL RIDGE LIES E TO W ALONG 28N ACROSS THE ATLC AND N FL INTO SE AL. THE RIDGE MOVES SO LITTLE OVER THE NEXT 5 DAYS THAT WE SEEM TO BE CHASING THE NOISE LEVEL IN THE MODELS AND MAKING ADJUSTMENTS EACH RUN. THUS I CHANGED SYNOPSIS WORDING ON THIS MORNINGS PACKAGE TO DENOTE BASICALLY A QUASI-STATIONARY RIDGE...AGAIN RATHER THAT FORECASTING A RIDGE AXIS PSN EACH DAY. A TROPICAL WAVE WILL MOVE THE BAY OF CAMPECHE TONIGHT. WITH UPPER CYCLONE IN AREA EXPECT CONVECTION TO FLARE OVER WATER UNDER THE DIFFLUENT E SEMICIRCLE OF THE CYCLONE BY LATE THIS AFTERNOON AND CONTINUE INTO NIGHT HOURS AS BOTH WAVE AND UPPER CYCLONE ARE SHIFTING W WITH TIME. A TROPICAL WAVE ALONG 75W IS MOVING W ABOUT 18 KT UNDER LESS FAVORABLE CONDITIONS ALOFT FOR CONVECTION AS UPPER ANTICYCLONE IS FORECAST TO SHIFT NNW. BUT STILL EXPECT AT LEAST ISOLATED TSTMS W CARIBBEAN AND SRN GULF OF MEXICO WATERS WATERS WITH WAVE AXIS MOVING W OF BAY OF CAMPECHE AROUND SUNRISE WED. A LOW LEVEL CYCLONIC CIRCULATION...NEAR 11N51.5W AT 12Z THIS MORNING STILL ACCOMPANIES A TROPICAL WAVE. ALTHOUGH CLUSTERS OF CONVECTION FLARE INTERMITTENTLY OVERCOMING DRY AIR ALOFT TO THE NW...THE CELLS DO NOT BAND. STILL EXPECT THIS SURFACE LOW TO MOVE W NW 15 KT THROUGH THE TROPICAL ATLC WATERS S OF 13N TONIGHT THROUGH EARLY MON NIGHT...AND THROUGH THE SE CARIBBEAN TUE THROUGH THU...WITH AN ROUGHLY EXTRAPOLATED 5 DAY PSN AT 12Z FRI NEAR 15N80W. BUT WITH NEW GUIDANCE JUST ARRIVING MAY SHIFT THE FORECAST PSN N ON AFTERNOON PACKAGE AFTER NHC RUNS THE 18Z GUIDANCE. IN ANY EVENT I EXPECT TO CONTINUE THE MENTION OF POSSIBLE TROPICAL CYCLONE DEVELOPMENT IN TEXT AND GRAPHICS BUT REALLY ONLY FORECASTING NE-E WINDS 20 KT SEAS TO 8 FT WITHIN 240 N SEMICIRCLE AS DEPICTED ON 0935Z QSCAT PASS AND SHIP AND BUOY REPORTS AT 12Z THIS MORNING. .WARNINGS... ATLC...NONE. CARIBBEAN...NONE. GULF OF MEXICO...NONE. FORECASTER NELSON