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000 FXUS62 KMFL 100529 AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 1229 AM EST WED FEB 10 2010 .AVIATION...CLOUDS WILL GRADUALLY MOVE EAST AND OUT OF S FL THROUGH THE NEXT FEW HRS LEAVING IMPROVING CEILINGS AND THE REST OF THE PERIOD IN VFR CONDITIONS. WINDS WILL BECOME NW AND BE GUSTY AT TIMES. /TINGLER && .PREV DISCUSSION... /ISSUED 707 PM EST TUE FEB 9 2010/ PREVIOUS DISCUSSION... ..FREEZING TEMPS POSSIBLE PARTS OF THE INTERIOR WEDNESDAY NIGHT WITH A SIGNIFICANT COOL DOWN ELSEWHERE... THERE REMAINS LITTLE OVERALL CHANGE TO THE FCST REASONING THROUGH THE REMAINDER OF THIS WEEK. THE MAIN CHALLENGE WILL BE LOW TEMPERATURE FCST WEDNESDAY NIGHT/THURSDAY MORNING. MODEL GUIDANCE CONTINUES TO AGREE THAT A STRONG/DEEP CLOSED LOW ENTERING THE OHIO VALLEY WILL MOVE QUICKLY OFF THE MID ATLC CST BY TOMORROW AFTERNOON. SOUTHERN STREAM ENERGY WILL PHASE WITH THIS LOW...LEADING TO A RAPIDLY DVLPG AND STRONG SFC LOW OFF THE MID ATLC/SRN NEW ENGLAND CST. THIS PROCESS WILL SWING A STRONG COLD FRONT ACROSS THE AREA QUICKLY THIS EVENING. BASED ON THE FRONTS CURRENT POSN AND MVMT...LOOKS LIKE THE FRONT WILL MOVE THROUGH MOST OF SOUTH FL BY OR JUST AFTER 06Z. CHANCES FOR RAIN SHOULD REMAIN HIGHEST FROM LAKE OKEECHOBEE NORTHWARD...BUT SCATTERED SHOWERS ARE STILL PSBL ACROSS THE ENTIRE AREA MAINLY FROM MID/LATE AFTN THROUGH AROUND MIDNIGHT AHEAD OF THE FRONT. THERE STILL APPEARS TO BE TOO LITTLE INSTABILITY FOR MUCH IF ANY THUNDER AT THIS TIME. BREEZY/WINDY AND COOLER CONDITIONS WILL MOVE IN BEHIND THE FRONT...THOUGH THE STRONGEST COLD ADVECTION LAGS BEHIND THE FRONT UNTIL TOMORROW. WEDNESDAY WILL BECOME MOSTLY SUNNY IF IT DOESN`T START OUT THAT WAY...AND BREEZY WITH THE STRONG COLD ADVECTION...GOOD MIXING...AND 20-25KT WINDS IN THE BOUNDARY LAYER. HIGHS WILL RANGE FROM THE 60S MOST AREAS TO AROUND 70 RIGHT ALONG THE SOUTHEAST CST. SFC HIGH PRESSURE WILL ANCHOR OVER THE MISSISSIPPI VALLEY TOMORROW NIGHT...BUT AN EXTENSION OF THE RIDGE WILL NOSE DOWN THE FL PENINSULA AS IS TYPICALLY THE CASE IN THESE SITUATIONS. SKIES SHOULD BE NO MORE THAN PARTLY CLOUDY...AND THESE CONDITIONS SHOULD COMBINE TO ALLOW WINDS TO DECOUPLE IN THE BOUNDARY LAYER ACROSS AT LEAST THE WESTERN INTERIOR. 1000-850MB THICKNESSES CONTINUE TO BE FCST JUST BELOW 1330M...AND WITH GOOD RADIATIONAL COOLING TEMPERATURES COULD DROP TO AROUND OR JUST BELOW FREEZING ACROSS PARTS OF GLADES...HENDRY...AND NORMALLY COLDER PARTS OF INTERIOR COLLIER COUNTY. WINDS SHOULD STAY UP SOME IN THE 5 TO 10 MPH RANGE ACROSS THE ERN HALF OF SOUTH FL...WHICH SHOULD PREVENT TEMPS FROM DROPPING TO FREEZING IN MOST AREAS. THE EXCEPTION MAY BE THE AG AREAS OF CENTRAL PALM BEACH COUNTY THAT WILL NOT BE QUITE DOWNWIND OF THE LAKE...AND MAY DECOUPLE SOME AND ARE TYPICALLY A FEW DEGREES COOLER. WILL GO AHEAD WITH A FREEZE WATCH FOR ALL OF THE ABOVE AREAS AT THIS TIME. ELSEWHERE...LOW TEMPS WILL LIKELY DROP INTO THE MID-UPPER 30S ACROSS METRO/COASTAL PALM BEACH COUNTY...AS WELL AS FAR WESTERN SUBURBS OF FT. LAUDERDALE ALONG THE SAWGRASS EXPWY AND U.S. 27...AND NORMALLY COOLER SOUTHERN/WESTERN SUBURBS OF MIAMI SUCH AS HOMESTEAD AND THE REDLANDS. TEMPS SHOULD REMAIN AROUND 40 IN THE NAPLES AREA AND AROUND OR JUST ABOVE 40 ACROSS THE DOWNTOWN/BEACH AREAS OF FT. LAUDERDALE AND MIAMI. WITH WINDS STAYING UP...WIND CHILLS COULD DROP BELOW 35F FOR 3 OR MORE HRS...MOST LIKELY ACROSS METRO/COASTAL PALM BEACH COUNTY...COASTAL COLLIER COUNTY INCLUDING NAPLES...AND MOST OF THE EAST COAST METRO AREAS...AND A WIND CHILL ADVISORY MAY BE NEEDED IN THESE AREAS. ONE MORE DRY DAY IS IN STORE FOR THURSDAY THOUGH IT WILL BE COOL AS HIGH CLDS BEGIN TO INCRS AHEAD OF THE NEXT STORM SYSTEM TAKING SHAPE ACROSS THE WRN GULF OF MEXICO. THIS SYSTEM WILL TRACK ACRS OR EVEN TO THE SOUTH OF SOUTH FL FRIDAY AFTN/NIGHT WITH A WEAK BUT FAST MVG SFC LOW. AHEAD OF THIS SYSTEM IT WILL STILL BE COLD THURSDAY NIGHT BUT PSBLY NOT AS COLD REGION WIDE AS MID/HIGH CLDS MAY START TO INCRS. WILL HOLD TEMPS NEAR OR JUST ABV FREEZING ACROSS THE SAME AREAS MENTIONED ABV FOR NOW. FRIDAY WILL FEATURE INCRSG CLOUDS WITH A POTENTIALLY STEADY MODERATE TO OCCASIONALLY HEAVY RAIN DVLPG DURING THE DAY AS OVERRUNNING/ISENTROPIC LIFT INCRS...LASTING INTO THE OVERNIGHT USING THE GFS/ECMWF TIMING FOR THIS SYSTEM. TEMPS MAY BE WELL BELOW GUIDANCE FRIDAY AND IT COULD VERY WELL BE A COOL/RAW DAY IF THE CLDS/RAIN DVLP EARLY ENOUGH. THEREAFTER...WEAK SFC HIGH PRESSURE WILL SETTLE ALONG THE GULF CST ALLOWING CONDS TO CLEAR OUT SOME FOR THE UPCOMING WEEKEND...THOUGH THE AMPLIFYING ERN CONUS UPR TROUGH WILL LIKELY ALLOW FOR PERIODS OF HIGH CLDS AT TIMES. TEMPS WILL COOL SLIGHTLY ONCE AGAIN OVER THE WEEKEND. MARINE... LITTLE CHANGE TO THE MARINE PACKAGE THIS AFTN. WINDS WILL INCRS OUT OF THE S/SW BEFORE SHIFTING W/NW AROUND OR JUST ABV 20KTS ALL WATERS OVERNIGHT. NW WINDS WILL GRADUALLY SUBSIDE TO BELOW 20KTS WEDNESDAY...WITH NW WINDS PREVAILING INTO THURSDAY. SWELLS AFFECTING THE ATLC WATERS WILL CONTINUE TO DISSIPATE BY WEDNESDAY MORNING. SEAS WILL CONTINUE UP TO 9FT IN THE GULF STREAM AND 8FT IN THE OFFSHORE GULF WATERS THROUGH THURSDAY. ROUGH CONDS WILL LIKELY CONTINUE WITH ELEVATED WINDS AND SEAS INTO THE UPCOMING WEEKEND. FIRE WEATHER... WILL ISSUE A FIRE WX WATCH FOR ALL ZONES EXCEPT COASTAL COLLIER AND FAR SOUTH DADE COUNTY TOMORROW AS A MUCH DRIER AIRMASS OVERSPREADS THE RGN. MODEL FCST SOUNDINGS SHOW DEWPOINTS IN THE TEENS IN THE MIXED LAYER TOMORROW WHICH SHOULD HELP SFC DEWPOINTS TO DROP INTO THE 20S TO AROUND 30F...WHICH SHOULD YIELD AT LEAST SEVERAL HRS OF RH`S BELOW 35 PERCENT ACRS MUCH OF THE RGN. SIMILAR CONDS WILL LIKELY LINGER INTO THURSDAY WITH LOW RH`S PSBL ONCE AGAIN ACROSS THE SAME AREAS. RH`S WILL LIKELY STAY A TOUCH HIGHER IMMEDIATELY DOWNWIND OF LAKE OKEECHOBEE AS IS TYPICAL IN NWRLY FLOW PATTERNS. COASTAL COLLIER COUNTY MAY BE EXEMPT FROM THE LOW RH`S EACH DAY DUE TO ONSHORE FLOW HOLDING DEWPOINTS HIGHER...A TYPICAL POST-COLD FRONT SCENARIO IN NWRLY FLOW AS WELL. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 65 36 63 44 / 0 0 0 10 FORT LAUDERDALE 68 42 65 49 / 0 0 0 10 MIAMI 68 43 66 50 / 0 0 0 10 NAPLES 62 40 63 45 / 0 0 0 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...FIRE WEATHER WATCH FROM 11 AM EST THIS MORNING THROUGH THIS AFTERNOON FOR COASTAL BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH-GLADES-HENDRY-INLAND BROWARD-INLAND COLLIER- INLAND MIAMI DADE-INLAND PALM BEACH-MAINLAND MONROE-METRO BROWARD-METRO MIAMI DADE-METRO PALM BEACH. FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR GLADES-HENDRY-INLAND COLLIER-INLAND PALM BEACH. AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM- COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM. SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR BISCAYNE BAY-LAKE OKEECHOBEE. GM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM- COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT 20 NM-GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM 20 TO 60 NM. && $$ LONG TERM...47/RHG SHORT TERM/AVIATION...04/AT
