000 FXUS62 KMFL 130927 AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 527 AM EDT TUE MAY 13 2008 .DISCUSSION... LATEST ASOS AND MESONET OBS ACROSS MAINLAND SOUTH FLORIDA SUGGEST THAT LOW-LEVEL WINDS ARE GRADUALLY VEERING TO THE NORTHWEST... ALLOWING A COOLER AND MUCH DRIER AIRMASS TO FINALLY SPREAD SOUTHWARD OVER THE FORECAST AREA. FLOW IS EXPECTED TO SHIFT TO THE NORTHEAST ACROSS THE ATLANTIC COAST PORTION OF THE PENINSULA LATER TODAY...WITH WARMING LANDMASS OVER THE INTERIOR ALLOWING A GULF COAST SEA BREEZE TO FORM BY LATE AFTERNOON. MODELS CONTINUE TO ADVERTISE THE CENTER OF CANADIAN SURFACE RIDGE AXIS SLOWLY SHIFTING EASTWARD OFF THE COAST OF THE CAROLINAS OVERNIGHT...WITH PRESSURE GRADIENT ACROSS THE LOCAL AREA LIKELY REMAINING STRONG ENOUGH TO PREVENT LAND BREEZE DEVELOPMENT. NONETHELESS...EFFICIENT RADIATIONAL COOLING PRECESSES WILL OCCUR OVER THE INTERIOR...AND WILL UNDERCUT MOS LOW TEMPERATURES ALONG THE WEST COAST BY A FEW DEGREES ON WEDNESDAY MORNING TO REFLECT THIS. EXPECT SURFACE RIDGE TO CONTINUE DRIFTING SOUTHEASTWARD TO THE NORTH OF THE BAHAMAS ON WEDNESDAY...WITH WEAK COLD ADVECTION IN THE BOUNDARY LAYER RESULTING IN HIGH TEMPERATURES JUST A FEW DEGREES COOLER ALONG THE EAST COAST. SOUTHEAST FLOW REGIME IS EXPECTED TO BECOME ESTABLISHED ONCE AGAIN BY THURSDAY...AND WITH UPPER-LEVEL HEIGHTS EXPECTED TO BEGIN RISING...A RETURN TO WARM/HUMID CONDITIONS WILL OCCUR. IN THE EXTENDED FORECAST...GLOBAL MODELS CONTINUE TO SUGGEST THAT NORTHERN EXTENT OF A LARGE SUBTROPICAL RIDGE WILL REMAIN IN PLACE OVER SOUTH FLORIDA THROUGH THE END OF THE WEEK...AS A REX BLOCK BECOMES ESTABLISHED ACROSS THE WESTERN HALF OF NORTH AMERICA. ALL AVAILABLE GUIDANCE ALSO SUGGESTS THAT AN UNSEASONABLY DEEP UPPER LOW WILL DEVELOP OVER THE GREAT LAKES REGION THIS WEEKEND...WITH THIS FEATURE LIKELY PERSISTING INTO THE FIRST PART OF NEXT WEEK. THIS PATTERN WILL FAVOR DEEP-LAYER SOUTHWEST FLOW DEVELOPING ONCE AGAIN ACROSS SOUTH FLORIDA...WITH THE POTENTIAL FOR ANOTHER EPISODE OF VERY WARM TEMPERATURES...SIMILAR TO WHAT WAS EXPERIENCED OVER THE LAST COUPLE OF DAYS. ALTHOUGH A WEAK FRONTAL BOUNDARY MAY TRY TO PENETRATE THE AREA SOMETIME EARLY IN THE WEEKEND...RAIN CHANCES WILL REMAIN VERY LOW FOR THIS TIME OF YEAR. && .AVIATION... VFR CONDITIONS WILL PREVAIL TODAY. NORTHWESTERLY FLOW OVER THE REGION IS EXPECTED TO VEER INTO A NORTHEASTERLY FLOW BY THIS AFTERNOON. SMOKE FROM THE LAKE OKEECHOBEE AREA IS NOT CURRENTLY AFFECTING ANY OF THE EAST COAST TERMINALS AND IS NOT EXPECTED TO AS THE DAY PROGRESSES AND THE WIND VEERS. && .MARINE... SEAS ACROSS THE GULF STREAM CURRENTLY RUNNING IN THE 6-7 FOOT RANGE WILL SLOWLY SUBSIDE THROUGH THIS AFTERNOON AS WINDS WEAKEN AND VEER TO THE NORTHEAST. THUS...WILL MAINTAIN INHERITED SCA FOR HAZARDOUS SEAS THROUGH 13/18Z. OTHERWISE...EXPECT WINDS TO CONTINUE TO SLOWLY VEER TO THE SOUTHEAST BY THURSDAY...WITH SPEEDS GENERALLY REMAINING IN THE 10-15 KNOT RANGE AT MOST ACROSS ALL OF THE LOCAL WATERS. IT STILL APPEARS AS IF LARGE CYCLONE CURRENTLY MOVING EASTWARD OFF THE COAST OF THE MID-ATLANTIC STATES WILL GENERATE A SWELL THAT SHOULD BEGIN TO AFFECT THE ATLANTIC WATERS OFF THE COAST OF PALM BEACH COUNTY BY WEDNESDAY. THIS SWELL WILL LIKELY REACH 4 FEET AT MOST IN THE PALM BEACH COUNTY WATERS...AND SHOULD BEGIN TO SUBSIDE ON FRIDAY MORNING. NONETHELESS...THERE WILL BE AN INCREASING THREAT FOR RIP CURRENTS ALONG THE ATLANTIC COAST BEACHES BY THE MIDDLE OF THE WEEK. && .FIRE WEATHER... WILL MAINTAIN INHERITED RFW FOR ALL OF INTERIOR SOUTH FLORIDA...AS WELL AS THE GULF COAST...AS UNSEASONABLY LOW DEW POINT VALUES WILL RESULT IN LONG DURATION OF RH BELOW 35 PERCENT. CONDITIONS WILL BE MORE MARGINAL ACROSS THE EASTERN PORTION OF THE PENINSULA...WHERE NORTHEAST FLOW IS EXPECTED TO DEVELOP SOONER. ONE MORE DAY OF FIRE WEATHER CONCERNS WILL EXIST ACROSS THE NORTHWEST ZONES ON WEDNESDAY...BEFORE DEVELOPING SOUTHEAST FLOW RESULTS IN PROGRESSIVELY DEEPER MOISTURE BEING TRANSPORTED OVER THE AREA. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 85 69 82 70 / - - - - FORT LAUDERDALE 86 73 83 74 / - - - - MIAMI 87 72 83 72 / - - - - NAPLES 85 62 88 65 / - - - - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...RED FLAG WARNING FROM 10 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR FLZ063-FLZ066-FLZ067-FLZ069-FLZ070-FLZ071- FLZ073-FLZ075-FLZ174. RED FLAG WARNING FROM 10 AM THIS MORNING TO 6 PM EDT THIS AFTERNOON FOR FLZ072-FLZ074. AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ650-AMZ651-AMZ670-AMZ671. GM...NONE. && $$ LONG TERM...70/DD SHORT TERM/AVIATION...60/BD