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000 FXUS62 KMFL 251355 AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 955 AM EDT THU SEP 25 2008 .UPDATE... NO CHANGES TO THE GOING FORECAST THIS MORNING. LIGHTER NORTHEAST FLOW CONTINUES ACROSS SOUTH FLORIDA THIS MORNING...BUT WINDS ARE STILL BLOWING 15 TO 20 MPH ACROSS THE ATLANTIC WATERS AND BISCAYNE BAY. THIS SPEED CONVERGENCE CONTINUES TO GENERATE ISOLATED SHOWERS THAT MOVE SOUTHWEST AND ONSHORE ACROSS BROWARD AND MIAMI-DADE COUNTIES. WESTERN INTERIOR AND WEST COAST AREAS ARE MOSTLY SUNNY AND WILL LIKELY REMAIN SO THROUGH MUCH OF THE DAY AS THE 12Z TBW SOUNDING INDICATES VERY DRY AIR JUST OFF THE SURFACE WORKING SOUTH INTO THESE AREAS. DEWPOINTS HAVE FINALLY COME DOWN SOME ACROSS SOUTH FLORIDA WITH MOST OB SITES SHOWING DEWPOINTS IN THE MID 60S...THOUGH READINGS WERE STILL AROUND 70 ALONG THE EAST COAST NEAR THE SHOWERS. AS THE DAY PROGRESSES...DEWPOINTS SHOULD CONTINUE TO DROP SLOWLY ACROSS THE WESTERN INTERIOR AREAS TODAY AS DRY AIR BOTH MOVES SOUTH INTO THE REGION AND MIXES DOWN FROM ABOVE THE SURFACE...AND DEWPOINTS COULD FALL TO AROUND 60 BY SUNSET. THE THREAT OF MINOR COASTAL FLOODING AND SOME BEACH EROSION WILL CONTINUE ACROSS THE ATLANTIC COAST TODAY...WITH GREATEST CHANCES ACROSS THE PALM BEACH COUNTY COAST. THERE WERE SOME REPORTS OF MINOR COASTAL FLOODING AND BEACH EROSION ALONG THE BROWARD COUNTY COAST FROM LAST NIGHT`S HIGH TIDE CYCLE. LARGE BREAKERS AND DANGEROUS RIP CURRENTS ARE LIKELY TO CONTINUE AS SWELLS CONTINUE TO IMPACT THE LOCAL WATERS. && .MARINE... CURRENT MARINE FORECAST APPEARS TO BE ON TRACK THIS MORNING. SWELLS SHOULD CONTINUE AT THEIR HIGHEST LEVELS THROUGH EARLY THIS AFTERNOON...PEAKING AT 5-6FT ALONG THE PALM BEACH COAST AND 4-5FT FURTHER SOUTH. HIGHER SWELLS OF 6-8FT ARE LIKELY OFFSHORE. COMBINED SEAS OF 9-11FT WILL CONTINUE IN THE GULF STREAM BEFORE BEGINNING TO SLOWLY SUBSIDE TONIGHT INTO FRIDAY AS SWELLS DECREASE TO 3-5FT. BASED ON 14S PERIOD SWELLS AT BUOYS 41009 AND 41010 AND LOCAL CALCULATIONS...SWELL PERIODS COULD BE QUITE LONG IN OUR WATERS...AS HIGH AS 17S. UPDATE/MARINE: STRASSBERG && .PREV DISCUSSION... /ISSUED 735 AM EDT THU SEP 25 2008/ AVIATION...SHOWERS STILL CONTINUE TO ROLL IN OFF THE COAST OVER MIAMI-DADE COUNTY...SO WILL CONTINUE WITH VCSH FOR KMIA AND KTMB. ASIDE FROM THE POSSIBILITY OF BRIEF MVFR CONDITIONS POSSIBLE WITH THESE SHOWERS...VFR WILL PREVAIL THROUGH THE FCST PERIOD. EXPECT NE WINDS TO PREVAIL AT NEAR 10 KT TODAY...EXCEPT FOR A POSSIBLE SEA BREEZE DEVELOPING AT KAPF DURING THE AFTERNOON. /DG CURRENTLY...WINDS NE 15 TO 20 KT OVER THE ATLC BEHIND A WEAK FRONTAL BOUNDARY THAT HAS MOVED INTO THE UPPER KEYS/FLA BAY. SCATTERED SHOWERS OVER THE ATLC WATERS MOVING ONSHORE PALM BEACH COUNTY WITH A WIND SURGE AND MIAMI-DADE COUNTY. SHOWERS EXTEND TO THE MID INTERIOR BEFORE DISSIPATING. DISCUSSION...AS 50H RIDGE MOVES E FROM E CANADA AND NEW ENGLAND ..THE UPPER LOW/SURFACE LOW OFF OF THE SE U.S. COAST MOVE WESTWARD AND OVER THE SE U.S. BY FRI MORNING. BY SUN...THE UPPER SYSTEM/SUR -FACE LOW BEGIN TO WEAKEN AND MOVE NE ALONG THE EASTERN SEA BOARD. S FLA THOUGH REMAINS IN A WESTERLY FLOW ALOFT AS A BROAD LONG WAVE TROUGH THE EXTENDS FROM THE UPPER MIDWEST TO THE LOWER MS RIVER VALLEY WITH THE ATLC UPPER RIDGE TO THE SE. FOR THE SHORT TERM...TODAY THROUGH SAT...SOME CHANCE OF SHOWERS MAINLY E HALF OF AREA THIS MORNING AND INTO THE AFTERNOON EXTREME S AS LOW-LEVEL MOISTURE REMAINS ACROSS S FLA. MOISTURE LINGERS JUST S OF AREA TONIGHT. SW WINDS ALOFT FRI INTO SAT GRADUALLY BEGIN TO INCREASE MOISTURE AGAIN OVER S FLA. MINIMAL SHOWERS MAY OCCUR ACROSS THE EXTREME S PORTION OF THE PENINSULA FRI AND TO THE W COAST...EX -TREME S PENINSULA AND ATLC WATERS FRI NIGHT. ON SAT...THE CHANCES OF RAIN OVER MOST OF THE AREA WITH SOME THUNDER WILL BE POSSIBLE. EXTENDED...SUNDAY THROUGH THU...DEEP LAYERED MOISTURE PERSISTS THROUGH MID WEEK WITH SOUTHERLY FLOW ALOFT. CHANCES OF RAIN DAILY CAN BE EXPECTED. ANOTHER FRONT POSSIBLE MID WEEK WITH DRIER AND A BIT COOLER WEATHER ON THE HORIZON. MARINE...N/NE WINDS 15 TO 20 KNOTS THROUGH MID MORNING AFFECTING LAKE OKEECHOBEE...BISCAYNE BAY AND THE ATLC COASTAL WATERS...THEN THE WINDS BEGIN A DECREASE. THE MAIN ISSUE IS THE NE SWELLS GENERAT -ED BY THE SURFACE LOW OFF OF THE SE U.S. COAST. UPSTREAM OBS SHOW 10-13FT/11-13S SWELLS AT BUOYS 41009 AND 41010 WHICH LEAD TO PEAK SWELLS BETWEEN 6 AND 7 FT ALONG COASTAL PALM BEACH COUNTY BEFORE BEGINNING TO DECREASE TONIGHT. MAIN EFFECTS WILL BE SOME MINOR COASTAL FLOODING AT HIGH TIDE BETWEEN 5 TO 6 AM THIS MORNING AND AGAIN LATE THIS AFTERNOON AFFECTING THE PALM BEACH COUNTY COAST PRIMARILY BUT POSSIBLY PORTIONS OF BROWARD COUNTY AS WELL. SOME BEACH EROSION IS ALSO POSSIBLE. ATLC SEAS WILL PEAK AROUND 10-11FT ..MAINLY OFF OF PALM BEACH IN THE GULF STREAM. AS THE SURFACE LOW MOVES ONSHORE TONIGHT...THE SWELLS WILL BEGIN TO DECAY TONIGHT AS WELL BUT WILL CONTINUE TO AFFECT ATLC WATERS THROUGH SUN MORNING. NEEDLESS TO SAY...BOATING AND BEACH INTERESTS WILL BE AFFECTED. A COASTAL HAZARD MESSAGE ALREADY IN EFFECT FOR THE HIGH SURF ADVISORY AFFECTING PALM BEACH COUNTY AND ALL THE ASSOCIATED HAZARDS OF SOME COASTAL FLOODING...BEACH EROSION AND HIGH RIP CURRENT RISK. FOR THE BEACHES OF BROWARD AND MIAMI-DADE COUNTIES...MINOR BEACH EROSION AND HIGH RISK OF RIP EXPECTED. FIRE WEATHER...DEW POINTS DROP INTO THE LOWER 60S NW INTERIOR TODAY AND FRI AFTERNOON. RH VALUES WILL DROP TO THE LOWER TO MID 40S. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 85 69 87 71 / 10 10 10 10 FORT LAUDERDALE 86 72 87 73 / 10 10 10 10 MIAMI 87 71 88 72 / 10 10 10 10 NAPLES 87 69 87 69 / - 10 10 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH SURF ADVISORY UNTIL 8 AM EDT FRIDAY FOR FLZ168. AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT FRIDAY FOR AMZ650-AMZ651-AMZ670-AMZ671. GM...NONE. && $$ LONG TERM...15/JR SHORT TERM/AVIATION...04/AT