AFDMOB AREA FORECAST DISCUSSION...MESOSCALE UPDATE NATIONAL WEATHER SERVICE MOBILE AL 1115 PM CST SAT FEB 4 2012 .AVIATION UPDATE (05/06Z TAF ISSUANCE)...IFR/LIFR CIGS AND MVFR VSBYS IN FOG DEVELOPING AND EXPECTED TO CONTINUE THROUGH 12-14Z SUNDAY...BEFORE LIFTING TO MVFR CIGS BY MID TO LATE MORNING. ISOLATED TO SCATTERED SHOWERS ALSO POSSIBLE THROUGH AROUND 05/16Z AS A COLD FRONT MOVES THROUGH THE AREA. A DRIER NORTHWESTERLY FLOW IS EXPECTED ACROSS MOST OF THE REGION IN THE WAKE OF THIS FRONT BY MID MORNING SUNDAY. 12/DS .UPDATE...UPDATED ZONES TO REFLECT CURRENT PCPN TRENDS. MOST OF THE EARLIER ACTIVITY HAS DIMINISHED ACROSS THE AREA...WITH THE MAIN AREA OF LINGERING SHOWERS ALIGNED GENERALLY WITH I-65 IN ALABAMA FROM NEAR GREENVILLE DOWN TOWARD MOBILE. WILL MAINTAIN A SLIGHT CHANCE OF SHOWERS EAST OF I-65 DOWN TOWARD COASTAL ALABAMA AND THE WESTERN FLORIDA PANHANDLE OVERNIGHT...WITH ONLY A SLIGHT CHANCE OF SHOWERS NORTH AND WEST OF I-65 IN ALABAMA AND ON INTO INTERIOR SOUTHEAST MISSISSIPPI. ADDITIONAL RAINFALL ACCUMULATIONS WILL BE RATHER LIGHT IN MOST LOCATIONS...GENERALLY A TENTH OF AN INCH OR LESS. IF THERE ARE SLIGHTLY HIGHER TOTALS...IT WILL BE ALONG AND SOUTH OF I-65. AS THE RAINS TAPER OFF TONIGHT...WITH ABUNDANT GROUND MOISTURE AND LIGHT WINDS...THERE IS A CHANCE FOR PATCHY FOG TO DEVELOP ACROSS THE REGION OVERNIGHT...POSSIBLY DENSE IN SOME LOCATIONS ESPECIALLY NEAR THE COAST. THE FOG WILL DISSIPATE DURING THE MORNING HOURS ON SUNDAY AS MIXING INCREASES AND MUCH DRIER AIR BEGINS TO MOVE IN FROM THE WEST WITH THE FRONTAL PASSAGE. OTHERWISE NO CHANGES TO CURRENT FCST PACKAGE. GRIDS...ZFP AND GRAPHICAST HAVE ALL ALREADY BEEN UPDATED. 12/DS ...AFTERNOON DISCUSSION FOLLOWS... .SHORT TERM [TONIGHT AND SUNDAY]...AN ADJUSTMENT MADE TO COVERAGES OF SHOWERS AND TSTMS MADE FOR THE EVENING PACKAGE GIVEN LATEST RADAR TRENDS WHICH SHOWS A WELL DEFINED BAND OF SHOWERS/EMBEDDED STORMS MOVING EASTWARD INTO THE MISSISSIPPI ZONES. A QUARTER TO HALF INCH OF RAIN POSSIBLE WITH LOCALLY HIGHER AMOUNTS IN ANY STRONGER STORMS. /10 18 UTC (12PM LOCAL) SURFACE WEATHER MAP ANALYSIS HAS A COLD FRONT POSITIONED FROM THE MID SOUTH DOWN THROUGH CENTRAL LOUISIANA. THE FRONT WAS MOVING SLOWLY EASTWARD AND FORECASTERS ARE TRACKING AN AREA OF SHOWERS/EMBEDDED STORMS OUT AHEAD OF THE FRONT...MOVING ACROSS CENTRAL/SOUTHWEST MISSISSIPPI. STORMS ARE EXPECTED TO WEAKEN AS THEY TRACK INTO THE FORECAST AREA LATER THIS EVENING WITH A FLAT HIGH LEVEL FLOW AND FORCING ALONG THE FRONT DIMINISHING. FORECASTERS WILL KEEP THE HIGHER CHANCES OF SHOWERS/FEW STORMS OVER THE NORTHERN TIER OF ZONES AS WEATHER WILL BE MOVING IN EARLIER UP THERE...THAN TO THE SOUTH. COULD ALSO BE SOME PATCHY LATE NIGHT FOG FORMATION AS WINDS BECOME CALM TO LIGHT OVERNIGHT. EXTENT OF CLOUD COVER THOUGH WOULD HELP TO MITIGATE COVERAGE OF DENSE FOG. OVERNIGHT LOW TEMPERATURES VERY MILD FOR THIS TIME OF YEAR WITH NUMBERS MOSTLY IN THE LOWER/MID 60S. FRONTAL PASSAGE IS FORECAST BETWEEN DAYBREAK AND NOON SUNDAY WITH WET WEATHER SHIFTING EAST AND SOUTH OF THE AREA AS THE FRONT CLEARS. ALTHOUGH FRONT MOVES THROUGH...DAYTIME HIGHS SUNDAY STILL SOME 7 TO 10 DEGREES ABOVE CLIMATOLOGY. /10 .LONG TERM...HIGH PRESSURE ADVANCES EASTWARD ACROSS THE SOUTHERN STATES THROUGH THE MIDDLE HALF OF NEXT WEEK WITH DAILY HIGHS AND LOWS MUCH CLOSER TO WHAT WE EXPECT FOR THIS TIME OF YEAR. WILL STAY WITH A DRY FORECAST THROUGH WEDNESDAY WHICH ALSO HAS REASONABLE SUPPORT FROM THE BULK OF 04.12 UTC GUIDANCE. THE ECMWF AND GFS REMAIN IN FAIRLY GOOD AGREEMENT ON PIVOTING A CUT OFF UPPER LOW SLOWLY ACROSS THE BAJA THURSDAY AND FRIDAY WHILE SURFACE HIGH PRESSURE GENERALLY REMAINS IN PLACE OVER THE SOUTHERN STATES. THE 04.12 UTC SPECTRAL GUIDANCE LOOKS TO KEEP THE BEST MOISTURE TO OUR SOUTH AND THIS MAY REQUIRE A DOWNWARD ADJUSTMENT ON LATER SHIFTS TO PROBABILITIES OF PRECIP (POP) LATER IN THE WEEK. FOR NOW WILL LEAVE POP AS IS FOR THE CLOSE OF NEXT WEEK. TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONABLE LEVELS THROUGH THE PERIOD. /10 && .AVIATION...MVFR CIGS ARE EXPECTED TO PERSIST THROUGH THE AFTERNOON HOURS WITH A MOIST SOUTHEAST FLOW CONTINUING. A CHANCE FOR RAIN AND EMBEDDED THUNDER WILL APPROACH MOB/BFM AFTER 00Z...BUT WILL LIKELY SIGNIFICANTLY WEAKEN AS IT APPROACHES. IFR/LIFR CIGS ARE EXPECTED TO DEVELOP AFTER BETWEEN 03-06Z AND CONTINUE THROUGH 12-14Z SUNDAY BEFORE LIFTING TO MVFR CIGS BY MID TO LATE MORNING. A NW WIND SHIFT IS EXPECTED AROUND DAYBREAK AT MOB/BFM AND BY MID MORNING AT PNS AS A COLD FRONT MOVES THROUGH THE AREA. A SLIGHT CHANCE OF SHOWERS AND TSTMS WILL ACCOMPANY THE FRONT. 34/JFB && .MARINE...A LIGHT SOUTH TO SOUTHEAST FLOW WILL CONTINUE ACROSS THE MARINE AREA THIS EVENING AHEAD OF A SLOW MOVING COLD FRONT WHICH IS CROSSING THE MS RIVER LATE THIS AFTERNOON. A LINE OF SHOWERS AND THUNDERSTORMS IS LOCATED WELL AHEAD OF THE FRONT ACROSS SE MS AND SE LA. THIS LINE WILL LIKELY AFFECT AT LEAST THE WESTERN PORTION OF THE ALABAMA COASTAL WATERS...INCLUDING MOBILE BAY THIS EVENING. THE LINE IS EXPECTED TO WEAKEN AFTER SUNSET...SO THERE IS UNCERTAINTY ON HOW FAR EAST THE LINE WILL SURVIVE. AT THE VERY LEAST...GUSTY WINDS UP TO 30 KT AND HEAVY DOWNPOURS CAN BE EXPECTED IN ANY THUNDERSTORM ACTIVITY THAT TRAVERSES THE ALABAMA COASTAL WATERS THIS EVENING. WINDS WILL BECOME LIGHT AND VARIABLE AFTER MIDNIGHT...WHICH WILL AID IN THE FORMATION OF PATCHY DENSE FOG ALONG THE COAST AND IN AREA BAYS. THE COLD FRONT IS FORECAST TO PUSH THROUGH THE MARINE AREA ON SUNDAY...WITH A MODERATE TO STRONG OFFSHORE FLOW DEVELOPING BY SUNDAY NIGHT. WINDS WILL INCREASE TO EXERCISE CAUTION LEVELS AND MAY APPROACH SMALL CRAFT ADVISORY LEVELS. WINDS WILL DECREASE BY MONDAY WITH A LIGHT TO MODERATE OFFSHORE FLOW CONTINUING THROUGH MIDWEEK WITH THE CENTER OF HIGH PRESSURE MOVING FROM THE CENTRAL PLAINS INTO THE MIDWEST AND OHIO VALLEY. 34/JFB && .FIRE WEATHER...COLD FRONT...APPROACHING FROM THE WEST TONIGHT...MAKES PASSAGE BETWEEN DAYBREAK AND NOON ON SUNDAY MORNING. SHOWERS AND A FEW THUNDERSTORMS POSSIBLE TONIGHT WILL BE ENDING SUNDAY MORNING. HUMIDITY REMAINS ABOVE CRITICAL LEVELS THE NEXT COUPLE DAYS WITH DAYTIME DISPERSION MOSTLY AVERAGE. /10 && .PRELIMINARY POINT TEMPS/POPS... MOBILE 60 70 44 63 / 60 20 05 05 PENSACOLA 62 73 47 64 / 40 20 05 05 DESTIN 63 72 49 63 / 30 20 10 05 EVERGREEN 61 71 42 63 / 60 20 05 05 WAYNESBORO 56 67 40 61 / 80 10 05 05 CAMDEN 60 69 41 64 / 80 20 05 05 CRESTVIEW 61 76 46 67 / 40 20 05 05 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$