000 FXUS62 KMFL 100530 AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 1230 AM EST FRI FEB 10 2012 .AVIATION...AREA OF SHOWERS/RA EXPECTED TO CONTINUE TO AFFECT ERN TERMINALS THROUGH AT LEAST 09Z. MVFR CEILINGS AND/OR VIS COULD BRIEFLY OCCUR. A FRONTAL BOUNDARY SHOULD CONTINUE TO MOVE SLOWLY NORTH THIS MORNING WITH THE HIGHEST PROBABILITY OF RA EXPECTED NEAR KPBI FRI AFTERNOON. SFC WINDS WILL SHIFT GRADUALLY FROM EAST THIS MORNING TO SE BY FRI AFTERNOON AND SW BY FRI EVENING AHEAD OF AN APPROACHING COLD FRONT FROM THE NORTH. WIND SPEEDS WILL REMAIN MAINLY BETWEEN 8-13 KNOTS WITH HIGHER GUSTS NEAR SHWRS. && .PREV DISCUSSION... /ISSUED 811 PM EST THU FEB 9 2012/ UPDATE...CONVECTIVE SHOWERS HAVE DEVELOPED ALONG OUT SE COAST. THIS IS LOCATED JUST NORTH OF A WEAK FRONTAL BOUNDARY OVER THE KEYS. THE EVENING MIAMI SOUNDING SHOWS A MOIST PROFILE/PW OF 1.73 INCHES/WITH LOW LEVEL WINDS OUT OF THE NORTHEAST BUT WIND FLOW BECOMING S-SW ABOVE 7K FT. THIS IS AN OVERRUNNING SCENARIO...ALONG WITH COASTAL CONVERGENCE ON THE NE SURFACE WIND FLOW...RESULTING IN NUMEROUS SHOWERS AFFECTING THE MIAMI-DADE COAST...AND LIKELY ALONG THE BROWARD COAST IN A FEW HOURS. SO HAVE INCREASED POPS TO 60% FOR THESE AREAS. THE TREND IS EXPECTED TO BE GRADUAL LESSENING OF THE ACTIVITY WITH TIME AS LOW LEVEL WINDS BEGIN TO VEER AND CONVERGENCE WEAKENS. HOWEVER...SCATTERED SHOWERS ARE EXPECTED EAST COAST THROUGHOUT THE NIGHT. THE EVENING MIAMI SOUNDING SHOWS PERHAPS JUST ENOUGH INSTABILITY FOR A TSTORM TO DEVELOP AND AFFECT MAINLY THE ATLANTIC WATERS WHERE INSTABILITY WILL BE GREATEST OVERNIGHT. /GREGORIA PREV DISCUSSION... /ISSUED 621 PM EST THU FEB 9 2012/ AVIATION...SCT SHRA CONTINUE TO MOVE IN FROM THE ATLANTIC BUT MOST CURRENTLY S OF THE E CST TERMINALS SO ONLY HAVE INCLUDED VCSH IN THE TAFS AT THIS TIME. ABUNDANT CLOUD COVER WITH PREVAILING CIGS AOA 030-035 WITH SOME SCT LOWER AROUND 015-020 PRIMARILY AFT 09Z. COULD HAVE AN OCCASIONAL LOWER CIG AT THAT TIME BUT NOT CONFIDENT JUST YET TO PLACE IN THE FCST. SFC WIND WILL SLOWLY SHIFT TO THE ESE LATER TONIGHT AND SE AFT 16Z FRIDAY. WIND COULD BECOME SSW LATE IN THE TAF PERIOD BUT WILL LIKELY STAY SSE FOR MUCH OF THE FCST SO HELD OFF INCLUDING THOSE WIND SHIFTS AT THIS TIME. INCREASING CHANCES FOR SHRA ON FRIDAY AS THE FRONT APPROACHES BUT MOSTLY FARTHER N SO ONLY INCLUDED PROB30 FOR KPBI AND VCSH ELSEWHERE. KOB PREV DISCUSSION... /ISSUED 248 PM EST THU FEB 9 2012/ UNSETTLE WEATHER THROUGH SATURDAY MORNING BEFORE MUCH COOLER AND DRIER WEATHER WORKS INTO SOUTH FLORIDA FOR SUNDAY INTO EARLY NEXT WEEK... DISCUSSION... THE STATIONARY FRONT OVER THE FLORIDA STRAITS WILL MOVE NORTH THROUGH SOUTH FLORIDA TONIGHT AND BE LOCATED OVER CENTRAL FLORIDA ON FRIDAY. THIS WILL ALLOW FOR ISOLATED SHOWERS AND POSSIBLE PATCHY FOG OVER THE INTERIOR AND WEST COAST METRO AREAS TONIGHT...WITH SCATTERED SHOWERS ALONG THE EAST COAST METRO AREAS. THE SCATTERED SHOWERS WILL CONTINUE OVER SOUTH FLORIDA ON FRIDAY...EXCEPT FOR THE NORTHEAST PORTION OF THE CWA WHERE SHOWERS WILL BE LIKELY ALONG WITH A FEW THUNDERSTORMS...DUE TO THE STEERING FLOW BEING IN A SOUTHWEST DIRECTION PUSHING THE WEST COAST SEA BREEZE EAST AND COLLIDING WITH THE EAST COAST SEA BREEZE AND THE LAKE OKEECHOBEE BREEZE. THE FRONT WILL REMAIN STATIONARY FRIDAY NIGHT OVER CENTRAL FLORIDA...AS LOW PRESSURE OVER THE SOUTHWEST GULF OF MEXICO MOVES NORTHEAST AND THROUGH CENTRAL FLORIDA. AT THE SAME TIME...A MID TO UPPER LEVEL JET OF 100 TO 120 KNOTS ALONG WITH A LOW LEVEL JET OF 40 TO 50 KNOTS WILL BE MOVING THROUGH CENTRAL FLORIDA. THIS WILL PUT THE AREAS NORTH OF ALLIGATOR ALLEY IN THE RIGHT ENTRANCE OF THE JETS...AND IN THE VARIABLE AREA FOR SHOWER AND THUNDERSTORMS DEVELOPMENT. THEREFORE...THE POPS WILL BE RAISE TO LIKELY CAT FOR AREAS NORTH OF THE ALLIGATOR ALLEY WITH SCATTERED STORMS. AREAS TO THE SOUTH OF ALLIGATOR ALLEY WILL SEE POPS IN THE CHANCE RANGE ALONG WITH THE SLIGHT CHANCE OF SEE STORMS. THE LOW PRESSURE WILL THEN CONTINUE TO MOVE NORTHEAST INTO THE WESTERN ATLANTIC WATERS WHILE DEEPENING ON SATURDAY PUSHING THE COLD FRONT SOUTHWARD THROUGH THE CWA SATURDAY MORNING. THIS WILL KEEP THE CHANCE OF SHOWERS GOING OVER THE AREA SATURDAY MORNING BEFORE TAPERING DOWN IN THE AFTERNOON HOURS...AS THE DRIER AIR TO THE NORTH WORKS INTO THE CWA. A VERY STRONG HIGH PRESSURE SYSTEM OF 1045 TO 1050 MBS IS ALSO FORECAST TO MOVE OUT OF CENTRAL CANADA FRIDAY AND MOVE SOUTH INTO THE SOUTHEAST UNITED STATES LATE THIS WEEKEND INTO EARLY NEXT WEEK. THIS WILL CONTINUE TO BRING IN THE VERY DRY AND MUCH COOLER WEATHER TO THE AREA LATE THIS WEEKEND INTO EARLY NEXT WEEK ALONG WITH KEEPING THE WEATHER DRY OVER SOUTH FLORIDA. THE GFS 12Z RUN AT THIS TIME SHOW THE 1000-850 MB THICKNESSES TO GET DOWN TO AROUND 1325-1330 AROUND THE LAKE OKEECHOBEE AREA TO 1340-1345 OVER MIAMI-DADE COUNTY BY SUNDAY MORNING. THIS MEANS THAT THE LOWS SATURDAY NIGHT SHOULD BE ABLE TO GET DOWN INTO THE 40S OVER MOST LOCATIONS...EXCEPT AROUND 40 WEST OF LAKE OKEECHOBEE AND UPPER 40S TO MID 50S OVER THE EAST COAST METRO AREAS. THE NORTHERLY WINDS WILL ALSO INCREASE SATURDAY NIGHT AND SHOULD BE BREEZY TO WINDY CONDITIONS BY SUNDAY MORNING. THIS IN TURN WILL ALLOW FOR THE WIND CHILL READINGS TO FALL INTO THE UPPER 30S TO MID 40S OVER THE MOST OF THE CWA...EXCEPT MID 40S TO LOWER 50S EAST COAST METRO AREAS AND MID TO UPPER 30S WEST OF LAKE OKEECHOBEE. HIGHS ON SUNDAY WILL BE IN THE UPPER 60S TO LOWER 70S ACROSS SOUTH FLORIDA...AS THE DRY AIR REMAINS IN PLACE OVER SOUTH FLORIDA. SUNDAY NIGHT...THE WINDS WILL BE LIGHT AND VARIABLE OVER THE CWA ALLOWING FOR GOOD RADIATIONAL COOLING. THIS WILL ALLOW FOR THE LOWS TO FALL DOWN TO THE UPPER 30S TO LOWER 40S OVER THE INTERIOR AND WEST COAST METRO AREAS TO THE MID 40S TO LOWER 50S EAST COAST METRO AREAS. THE ONLY EXCEPTION TO THIS IS WEST OF LAKE OKEECHOBEE WHERE THE LOWS WILL BE ABLE TO FALL INTO THE MID TO UPPER 30S. EXTENDED FORECAST... THE STRONG HIGH WILL THEN MOVE EAST INTO THE WESTERN ATLANTIC WATERS EARLY TO MIDDLE OF NEXT WEEK. THIS WILL ALLOW FOR THE WIND FLOW OVER THE CWA TO SWING TO A MORE EASTERLY DIRECTION...AND ALLOW FOR A GRADUAL WARM UP THROUGH MIDDLE OF NEXT WEEK. THE WEATHER WILL ALSO REMAIN DRY OVER THE CWA FOR EARLY TO MIDDLE OF NEXT WEEK. MARINE... THE WINDS WILL BE FROM THE EASTERLY DIRECTION THIS AFTERNOON INTO TONIGHT AT 15 KNOTS OR LESS. THE WINDS WILL THEN SWING TO A SOUTH TO SOUTHWEST DIRECTION ON FRIDAY AND FRIDAY NIGHT OVER SOUTH FLORIDA WATERS WITH SPEEDS LESS THAN 15 KNOTS. THE WINDS WILL THEN SWING FROM A SOUTHWEST DIRECTION SATURDAY MORNING TO A NORTHERLY DIRECTION SATURDAY AFTERNOON INTO SUNDAY...AS SPEEDS INCREASE FROM AROUND 15 KNOTS SATURDAY MORNING TO 20 TO 25 KNOTS SATURDAY NIGHT INTO SUNDAY. THIS WILL KEEP THE SEAS BELOW 6 FEET TONIGHT INTO SATURDAY MORNING OVER ALL OF SOUTH FLORIDA ATLANTIC AND GULF WATERS...BEFORE BUILDING TO 8 FEET IN THE ATLANTIC WATERS BY SUNDAY AND UP TO 6 OR 7 FEET IN THE OFFSHORE GULF WATERS. THEREFORE...BOATING CONDITIONS WILL GO DOWN HILL QUICKLY SATURDAY AFTERNOON INTO SATURDAY NIGHT OVER ALL OF THE LOCAL WATERS BEHIND THE PASSAGE OF THE COLD FRONT. FIRE WEATHER... THE RELATIVE HUMIDITIES WILL REMAIN ABOVE THE 35 PERCENT CRITICAL VALUE ON FRIDAY AND SATURDAY OVER ALL OF SOUTH FLORIDA. HOWEVER...ON SUNDAY THE RELATIVE HUMIDITIES WILL FALL DOWN 20S OVER MOST LOCATIONS FOR SEVERAL HOURS DUE TO THE VERY DRY AIR WORKING INTO THE AREA FROM THE NORTH ON SUNDAY. THE 20 FOOT WINDS WILL ALSO BE RUNNING AROUND 15 MPH OVER ALL OF SOUTH FLORIDA ON SUNDAY. IF THIS TREND CONTINUES IN LATER FORECAST...THEN A FIRE WEATHER WATCH WILL MORE LIKELY BE NEEDED FOR SOME OR ALL OF SOUTH FLORIDA FOR SUNDAY SOMETIME FRIDAY OR SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 81 67 73 50 / 70 70 30 10 FORT LAUDERDALE 81 69 75 52 / 60 60 40 10 MIAMI 82 68 76 52 / 50 50 40 10 NAPLES 79 65 74 47 / 40 60 30 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...84/AK AVIATION/RADAR...47/RGH