000 AGXX40 KNHC 130545 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 145 AM EDT SUN JUL 13 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. SW N ATLC... SHORT-TERM (TODAY THROUGH MON NIGHT)...HURRICANE BERTHA HAS BECOME TRAPPED WITHIN A DEEP-LAYERED RIDGE AND IS NOW MEANDERING ABOUT 200 NM SE OF BERMUDA...BUT IS EXPECTED TO RESUME A SLOW NWD MOTION WITHIN THE NEXT 48 HRS OR SO. THE LATEST NHC FCST HAS THE TROPICAL STORM FORCE RADII JUST BARELY GRAZING SW OF 31N65W BUT NOT ENOUGH TO WARRANT A WARNING. THERE IS STILL SOME UNCERTAINTY IN THE FCST SINCE BERTHA IS MEANDERING...AND THE 48-HR TC WIND PROB IS SHOWING AT MOST A 40-50% CHANCE THAT TS WINDS COULD SPREAD W OF 65W. ELSEWHERE...HIGH PRES NEAR 28N72W WILL SLIDE SE AND MERGE WITH THE ATLC RIDGE WHICH WILL EXTEND FROM 25N65W TO W CUBA. BROAD LOW PRES OVER N FLORIDA/S GEORGIA WILL PRODUCE S/SW WINDS OVER THE NW WATERS AS THE RIDGE IS SUPPRESSED TO THE S. ALTHOUGH THE GFS IS SUFFERING FROM A LITTLE BIT OF CONVECTIVE FEEDBACK (AND SHOWS SPOTTY WINDS UP TO 30 KT)...THE ENSEMBLES HAVE COME IN LINE AND INCREASE FLOW TO 15-20 KT BY MON/MON NIGHT WITH SEAS BUILDING TO 6 FT. ELY WINDS INCREASE TO 15-20 KT OVER THE SE WATERS MON NIGHT AS THE N END OF A TRPCL WAVE APPROACHES FROM THE E. LONG-TERM (TUE THROUGH THU)...RIDGE AXIS STILL EXTENDS FROM 28N65W TO W CUBA ON TUE AS THE TRPCL WAVE MOVES ACROSS THE SRN WATERS. WINDS S OF 23N WILL INCREASE TO 20-25 KT BY WED AND SPREAD W...WITH SEAS BUILDING TO 9 FT E OF THE SRN BAHAMAS. OTHERWISE...THE RIDGE MOVES LITTLE THROUGH THE PERIOD STAYING NEAR 28N AND THE SW WINDS DIMINISHING OFF NE FLORIDA. **************************************************************** CARIBBEAN... SHORT-TERM...PRES GRADIENT OVER THE W/CNTRL CARIBBEAN HAS SLACKENED UP JUST A BIT BUT AN AREA OF 20-25 KT STILL LIES S OF 15N TO THE COAST OF COLOMBIA. A TRPCL WAVE IS ROUGHLY ALONG 53W/54W AND WILL MOVE INTO THE TRPCL N ATLC WATERS THIS MORNING WITH NE/E WINDS INCREASING TO 15-20 KT OVER THE CNTRL PART THEN TO 20-25 KT TONIGHT THROUGH MON NIGHT. THE WAVE CROSSES THE LESSER ANTILLES ON MON RESULTING IN THE 20-25 KT WIND SWATH TO SPREAD INTO THE NE CARIBBEAN BY MON NIGHT. WW3 BUILDS SEAS TO 8-11 FT E OF THE ISLANDS FROM 12N-20N TONIGHT THROUGH MON NIGHT THEN OVER THE NE CARIBBEAN BY LATE MON NIGHT. LONG-TERM...THE TRPCL WAVE CONTINUES TO MOVE W THROUGH THE CARIBBEAN NEAR 67W TUE...75W WED...THEN OVER THE W CARIBBEAN THU. A STRONG PRES GRADIENT WILL TRAIL THE WAVE AS HIGH PRES BUILDS IN AFTER ITS PASSAGE...MAINTAINING A SWATH OF STRONGER WINDS FROM THE NRN LEEWARD ISLANDS TO THE S/CNTRL CARIBBEAN WELL INTO THU. REGARDING THE POSSIBLE AREA OF LOW PRES MANY OF THE MODELS DEVELOP OVER THE CNTRL ATLC...THE ENSEMBLE MEAN ONLY BRINGS THE SYSTEM TO 53W BY THU NIGHT SO WILL NOT BE FACTORED INTO THE CURRENT FCST PACKAGE. **************************************************************** GULF OF MEXICO... SHORT-TERM...SFC RIDGE IS BEING SUPPRESSED SWD FROM THE NW GULF TO THE STRAITS OF FLORIDA AS A BROAD TROUGH DEVELOPS FROM SRN GEORGIA DOWN THE W COAST OF FLORIDA. 10-15 KT W/NW WINDS WILL SPREAD N OF 23N E OF 90W THROUGH MON AND WILL ALLOW SEAS TO BUILD TO 2-4 FT OVER THE NRN MIDDLE AND E GULF. OTHERWISE HIGH PRES OVER THE NW GULF WILL MAINTAIN VARIABLE WINDS THERE WITH LIGHT ELY FLOW OVER THE SW GULF. LONG-TERM...LITTLE CHANGE IS EXPECTED TO THE OVERALL PATTERN BY TUE AS LOW PRES DRIFTS S OVER N FLORIDA AND MAINTAINS W/NW FLOW OVER MUCH OF THE ERN GULF. THERE SEEMS TO BE FAIRLY GOOD MODEL AGREEMENT THAT THE LOW WILL DRIFT SW OVER THE FAR NE WATERS BY WED THEN DEGENERATE INTO A TROUGH OVER THE MIDDLE GULF ON THU. WINDS ARE EXPECTED TO REMAIN LIGHT BUT WILL RE-ESTABLISH AN ELY FLOW LATE WED/THU AS THE TROUGH MOVES W. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. .FORECASTER BERG. TROPICAL PREDICTION CENTER.