000 FXUS62 KMFL 101117 AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 617 AM EST WED FEB 10 2010 .AVIATION...A FEW CLOUDS WILL CONTINUE TO ROLL THROUGH THIS MORNING CREATING MVFR AND POSSIBLY AT TIMES EVEN IFR CONDITIONS... HOWEVER IN A FEW HRS CONDITIONS WILL GRADUALLY BECOME NEARLY CLEAR EVERYWHERE AND FOR THE REST OF PERIOD. WINDS WILL BE NORTHWEST AND GUSTY AT TIMES. /TINGLER && .PREV DISCUSSION... /ISSUED 403 AM EST WED FEB 10 2010/ ..POSSIBLE FREEZING TEMPERATURES ACROSS NORTHWEST INTERIOR LATE TONIGHT THROUGH THURSDAY MORNING... ..WIND CHILL VALUES COULD PLUMMET OVER THE EAST AND WEST COAST METRO AREAS EARLY THURSDAY MORNING... SHORT TERM...TODAY THROUGH THURSDAY...BOTH ECMWF AND GFS IN PRETTY GOOD AGREEMENT WITH REGARD TO THE COLD FRNT MOVING WELL SOUTH OF THE LOCAL AREA TODAY. A CANADIAN HIGH WILL MOVE RAPIDLY SOUTH ACROSS THE CENTRAL PLAINS WITH A WELL ESTABLISHED N-NW FLOW AFFECTING THE PENINSULA THROUGH THIS PERIOD. THIS WILL HELP TO ADVECT MUCH DRIER AND COLDER AIR OVER MAINLAND SOUTH FLORIDA WITH MAX TEMPS BARELY REACHING 70 EXTREME SOUTHERN AREAS THIS AFTERNOON. SIGNIFICANTLY COLDER TEMPS SHOULD BE EXPECTED OVER ALL OF S. FLORIDA LATE TONIGHT/THURSDAY MORNING WITH A GOOD PORTION OF THE NORTHWEST INTERIOR POSSIBLY REACHING FREEZING OR BELOW FREEZING TEMPS. BOTH, EAST AND WEST COAST METRO AREAS COULD SEE MIN TEMPS DIVING INTO THE UPPER 30S...EXCEPT FOR COASTAL BROWARD/METRO MIAMI WHERE TEMPS ARE EXPECTED IN THE L/M 40S. HOWEVER, LOW TEMPS ARE NOT THE ONLY PROBLEM TONIGHT...DEPENDING ON WIND SPEED, WIND CHILL VALUES COULD ALSO PLUMMET TO THE M/U 30S OVER ERN AND WESTERN METRO AND TO MUCH LOWER VALUES ACROSS INTERIOR SECTIONS JUST BEFORE SUNRISE THURSDAY. A WIND CHILL ADVISORY COULD BE ISSUED FOR SOME PORTIONS OF SOUTH FLORIDA LATER TODAY OR THIS EVENING. THE SFC HIGH SHOULD MOVE EAST OVER SE U.S. THURSDAY WITH SFC WINDS SHIFTING TO NE BY THU EVENING STARTING A RATHER QUICK WARMING TREND. FRIDAY THROUGH SATURDAY...ANOTHER SFC LOW IS EXPECTED TO DEVELOP OVER THE WESTERN GULF OF MEX AND MOVE TO JUST WEST OF THE PENINSULA BY FRI EVENING. WHILE BOTH GFS AND ECMWF AGREE ON THE SPEED OF THIS FEATURE ACROSS THE GULF...THERE IS DISAGREEMENT AS TO WHERE THE LOW WILL CROSS THE PENINSULA AND, IN TURN, IN THE TYPE OF WX, WIND DIRECTION AND SPEED OVER THE LOCAL AREA. ECMWF HAS THE LOW CROSSING FURTHER NORTH ACROSS CENTRAL FLORIDA WHILE GFS MOVES THE LOW RIGHT THROUGH S. FLORIDA. THIS WILL PUT S. FLORIDA UNDER A HIGH RISK OF SVR WX WITH VERY HIGH HELICITY VALUES AND THE ONLY LIMITING FACTOR BEING LIMITED INSTABILITY. HOWEVER...LATEST TREND IN THE GFS HAS BEEN TO MOVE THE LOW FURTHER NORTH IN EVERY RUN...SO A FURTHER NORTHWARD DISPLACEMENT OF THIS LOW TOWARD THE ECMWF SOLUTION IS POSSIBLE IN FUTURE RUNS. IN ANNY CASE...WL EXPECT WX ASSOCIATED WITH THIS FEATURE TO COME QUICKLY FRIDAY AFTERNOON/EVENING WITH HIGHEST POPS EXPECTED OVERNIGHT FRIDAY AND AN EQUALLY QUICK DRY UP SATURDAY AS THE LOW MOVES NE AND IS REPLACED BY A SFC HIGH OVER THE GULF OF MEX. LONG TERM...SUNDAY THROUGH TUESDAY...RELATIVELY DRY CONDITIONS SHOULD BE EXPECTED. A WEAK FRONT MAY APPROACH THE LOCAL AREA MONDAY HOWEVER IT SEEMS IT WILL LACK UPPER LEVEL SUPPORT AS MOST ENERGY REMAINS WELL NORTH. WL INDICATE ONLY A SLIGHT CHANCE OF PRECIP THROUGH THIS PERIOD WITH TEMPS REMAINING NEAR SEASONAL VALUES. MARINE...SFC WINDS WL SHIFT NW BEHIND THE FRONT THIS MORNING AND REMAIN ABOVE 20 KTS OVER MOST WATERS (EXCEPT NEAR SHORE GULF AND BISCAYNE BAY) AT LEAST THROUGH THIS EVENING. WIND SPEEDS SHOULD DECREASE TONIGHT BUT WILL REMAIN FROM THE NORTH THROUGH THURSDAY WITH VERY HAZARDOUS CONDITIONS IN THE GULF STREAM. SEAS IN THE GULF STREAM COULD FINALLY SUBSIDE THU EVENING JUST IN TIME FOR THE WINDS TO INCREASE AGAIN AHEAD OF THE NEXT COLD FRONT. FIRE WEATHER...MUCH DRIER AIR SPREADING SOUTH ACROSS S. FLORIDA TODAY WILL RESULT IN RH VALUES WELL BELOW 35% FOR SEVERAL HOURS THIS AFTERNOON AND EVENING...MOST OF SOUTH FLORIDA IS EXPECTED TO BE AFFECTED BY THESE LOW RH VALUES...EXCEPT WEST COAST LOCATIONS AND EXTREME SOUTHERN PORTIONS OF MIAMI-DADE. CONDITIONS COULD EVEN BE DRIER THURSDAY AFTERNOON WITH POSSIBLE THE ENTIRE FORECAST AREA BEING AFFECTED BY RH BELOW 35% FOR SEVERAL HOURS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 64 38 63 46 / 0 0 0 10 FORT LAUDERDALE 69 43 65 50 / 0 0 0 10 MIAMI 70 44 66 51 / 0 0 0 - NAPLES 64 38 63 42 / 0 0 0 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 6 PM EST THIS EVENING 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. FIRE WEATHER WATCH THURSDAY AFTERNOON FOR COASTAL BROWARD- COASTAL COLLIER-COASTAL MIAMI DADE-COASTAL PALM BEACH-FAR SOUTH MIAMI DADE-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 2 PM EST THURSDAY 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. SMALL CRAFT ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR LAKE OKEECHOBEE. GM...SMALL CRAFT ADVISORY UNTIL 4 AM EST THURSDAY FOR GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 9 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. && $$ LONG TERM...47/RHG SHORT TERM/AVIATION...04/AT