AFDMOB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 907 AM CDT TUE APR 19 2011 .UPDATE...WILL UPDATE FOR THE EXPIRATION OF THE DENSE FOG ADVISORY AND MINOR ADJUSTMENTS FOR TRENDS THIS MORNING. UPDATE OUT SOON. /29 && ** PREVIOUS DISCUSSION ** .SHORT TERM...FOR TODAY THROUGH TONIGHT...WARMER AND MORE HUMID CONDITIONS EXPECTED TODAY AND TONIGHT AS ONSHORE FLOW CONTINUES ACROSS FCST AREA. PATCHY FOG...DENSE IN SOME LOCATIONS...WILL BE POSSIBLE EARLY THIS MORNING BUT QUICKLY DISSIPATING AFTER ABOUT 14Z. A DENSE FOG ADVISORY IS IN EFFECT FOR INTERIOR SOUTH CENTRAL ALABAMA (GENERALLY ALONG AND EAST OF I-65) AS WELL AS FOR THE WESTERN FLORIDA PANHANDLE UNTIL 14Z. FOG HAS DEVELOPED IN THESE LOCATIONS AS WINDS ARE NEAR CALM AS THE AREA IS CLOSER TO THE CENTER OF THE SFC RIDGE OF HIGH PRESSURE. FARTHER TO THE WEST...OVER SOUTHWEST ALABAMA AND INTERIOR SOUTHEAST MISSISSIPPI SOUTHERLY WINDS IN THE 5 TO 10 KNOT RANGE AROUND THE WESTERN PERIPHERY OF THE RIDGE ARE KEEPING FOG AT THE SFC IN CHECK...BUT A LOW CIG DECK IS NOTED. AFTER THE LOW CLOUDS AND FOG DISSIPATE BY MID MORNING...EXPECT A MOSTLY SUNNY DAY WITH HIGHS RANGING FROM THE UPPER 70S COASTAL UP TO MID 80S INLAND. LOWS TONIGHT RANGING FROM THE UPPER 60S TO LOWER 70S. AGAIN A CHANCE OF PATCHY FOG OVERNIGHT TONIGHT. 12/DS FOR WEDNESDAY THROUGH THURSDAY...WEDNESDAY STARTS WITH AN UPPER SYSTEM MOVING OVER THE TENN/OHIO RIVER VALLEYS...TRAILING A FRONT OVER THE LOWER MISS RIVER VALLEY TO OVER THE SOUTHERN PLAINS. MOISTURE LEVELS HAVE BEEN ON THE INCREASE...SO WILL NOT BE SURPRISED TO SEE A FEW VERY LIGHT SHOWERS AROUND WEDNESDAY MORNING. THROUGH WEDNESDAY...AS THE THE MAIN UPPER DYNAMICS MOVE OFF...THE FRONT SAGS SOUTH OVER NORTHERN AL/MA...WITH SOME SHORTWAVE MOVING SOUTH WITH. THE NAM IS ADVERTISING THIS ENERGY BEING STRONGER...THUS POPS ARE HIGHER AS A RESULT. ALL GUIDANCE IS ADVERTISING THIS FRONT SAGGING TO A POINT JUST NORTH OF THE FA WEDNESDAY NIGHT...THEN BEGIN TO RETREAT NORTH OVER THE PLAINS THURSDAY AS THE SOUTHWARD PUSH OF THE FRONT WEAKENS AND SOUTHERLY WINDS SOUTH OF THE FRONT REGAIN CONTROL. WITH THE FOCUSING FRONT REMAINING NORTH OF THE FA. HAVE PAINTED BEST POPS OVER THE NORTHERN-MOST SECTIONS OF THE FA WEDNESDAY THROUGH THURSDAY AS A RESULT TAPERING DOWN AS ONE HEADS TOWARDS THE COAST. WITH MOISTURE LEVELS ABOVE SEASONAL...AND OVERNIGHT FOG DEVELOPMENT...AM EXPECTING WEDNESDAY NIGHT TEMPS TO BE WEEK ABOVE SEASONAL. DAYTIME...AM EXPECTING TEMPS...AWAY FROM THE COAST AND THE COOLING EFFECT OF THE FLOW OFF THE COAST...TEMPS A BIT ABOVE SEASONAL ARE EXPECTED. REMAIN A BIT CONCERNED THAT ANY CELLS THAT DO FORM COULD BECOME STRONG...WITH MODEL SOUNDINGS OVER THE NORTHERN HALF OF THE FA WELL ABOVE 2500 J/KG DURING THE AFTERNOON. WITH WEAK SHEAR...AM NOT EXPECTING ANY ORGANIZED SEVERE ACTIVITY...MORE OF A SUMMER MODE TYPE OF PRECIP...WITH PULSE TYPE STORMS...MEANDERING NORTH TO NORTHEAST AND IF ANY DO BECOME STRONG TO SEVERE...DAMAGING WINDS WILL BE THE PRIMARY THREAT. .LONG TERM...THURSDAY NIGHT ON...GUIDANCE IS ADVERTISING THE CONTINUED SOUTHERLY FLOW OVER THE SOUTHERN PLAINS TO THE WESTERN FLORIDA PANHANDLE. UPPER ENERGY MOVING OVER THE NORTHWESTERN CONUS...ALONG WITH A CLOSED SYSTEM ORGANIZING OVER THE EASTERN CARIBBEAN...WILL BUILD A SLIGHT RIDGE OVER THE EASTERN CONUS...THEN SHIFTS IT TO OFF THE EAST COAST BY SATURDAY MORNING. THE SURFACE RIDGE REMAINS STRETCHING OVER THE NORTHERN GULF COAST INTO THE WEEKEND...CONTINUING THE TREND OF WARMER THAN SEASONAL OVERNIGHT TEMPS AND TEMPS A BIT ABOVE SEASONAL. HELPING TO LIMIT THE MOISTURE LEVELS LATER IN THE WEEK INTO THE WEEKEND IS GUIDANCE ADVERTISING DRIER AIR STREAMING NORTH OVER THE FA...ON THE WEST SIDE OF THE UPPER RIDGE. OVER THE WESTERN CONUS...INTO AND THROUGH THE WEEKEND...BOTH THE GFS AND ECMWF ARE ADVERTISING INCOMING SHORTWAVE ENERGY DIGGING AN UPPER TROUGH...THEN SWINGING IT EAST. THE GFS IS MORE AGGRESSIVE IN SWINGING THE UPPER ENERGY/TROUGH EASTWARD AGAINST THE UPPER RIDGE OFF THE EAST COAST. WITH THE INCREASING SOUTHERLY FLOW AND APPROACHING UPPER TROUGH DRIVING A FRONT TOWARDS THE AREA THROUGH THE MIDDLE OF THE COMING WEEK...AM EXPECTING AN INCREASE IN THE CHANCE OF RAIN FOR THE COMING WEEK. && .AVIATION...(12Z ISSUANCE)LOW CLOUDS AND FOG OVER THE REGION THROUGH AROUND 14Z THIS MORNING WITH CIGS OF 600 FEET OR LOWER AND VSBYS AS LOW AS 1/4 MILE AT SOME LOCATIONS. IFR-LIFR CONDITIONS POSSIBLE THROUGH AROUND 14Z...AFTER WHICH CIGS WILL RISE/ERODE AND FOG WILL DISSIPATE LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. 12/DS && .MARINE...A RIDGE OF HIGH PRESSURE OFF THE ATLANTIC COAST WILL MAINTAIN A SOUTHERLY WIND FLOW OVER THE MARINE AREA THROUGH THE EARLY PART OF THE WEEKEND. A WEAKENING COLD FRONT WILL APPROACH THE COASTAL WATERS THROUGH THE WEEK...BECOMING STATIONARY TO THE NORTH OF THE MARINE AREA BY SATURDAY. AS THE FRONT APPROACHES DURING THE MIDDLE PART OF THE WEEK...THE ONSHORE FLOW WILL INCREASE BUT THEN DECREASE SLIGHTLY BY WEEKS END AS THE FRONT WEAKENS. 12/DS && .FIRE WEATHER...SOUTHERLY FLOW IS EXPECTED TO CONTINUE THROUGH THE REST OF THE WEEK...THE COMING WEEKEND AND INTO THE COMING WEEK. NO PROBLEMS NOTED WITH MOISTURE LEVELS...THROUGH AN APPROACHING UPPER SYSTEM WILL KEEP THE MIXING LAYER WINDS...AND DISPERSIONS...HIGH TODAY INTO THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... MOBILE 83 70 87 67 84 / 05 05 20 10 10 PENSACOLA 81 71 79 69 81 / 05 05 10 10 10 DESTIN 78 70 77 68 77 / 05 05 10 10 10 EVERGREEN 86 68 88 66 86 / 05 10 20 30 20 WAYNESBORO 87 70 88 66 84 / 10 10 30 30 30 CAMDEN 86 68 88 66 85 / 05 10 30 30 30 CRESTVIEW 86 63 88 63 86 / 05 05 10 10 10 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...DENSE FOG ADVISORY UNTIL 9 AM TUESDAY FOR THE FOLLOWING ZONES: BUTLER...CONECUH...COVINGTON...CRENSHAW...AND ESCAMBIA. FL...DENSE FOG ADVISORY UNTIL 9 AM TUESDAY FOR THE FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...COASTAL SANTA ROSA... INLAND ESCAMBIA...INLAND OKALOOSA...AND INLAND SANTA ROSA. MS...NONE. GM...NONE. && $$