804 FXUS64 KBMX 181540 AFDBMX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BIRMINGHAM AL 1040 AM CDT MON MAR 18 2013 .UPDATE... FOR MORNING DISCUSSION. && .DISCUSSION... TODAY LOOKS LIKE IT COULD BE THE STORY OF 2 OR 3 DIFFERENT TALES. WE START OUT THIS MORNING WITH AMPLE CLOUD COVER AND SCATTERED SHOWERS ACROSS A LARGE PORTION OF CENTRAL ALABAMA AS WELL AS THE MAIN ONGOING SITUATION...THE SQUALL LINE THAT HAS DEVELOPED IN NORTHEAST MISSISSIPPI. AS EXPECTED...THE MORNING CLOUD COVER IS HAMPERING THE DEVELOPMENT OF SFC BASED INSTABILITY...BUT THE SQUALL LINE DOES HAVE THE ENERGY FROM THE PARENT SURFACE LOW IN SOUTHERN KENTUCKY WITH WHICH TO WORK. THE LINE SHOULD REMAIN ELEVATED BUT WILL CARRY A LOW-END HAIL AND DAMAGING WIND THREAT. THIS IS EXPECTED TO CHANGE HOWEVER AS WE MOVE INTO THE AFTERNOON HOURS. MODEL GUIDANCE SUPPORTED BY WATER VAPOR SATELLITE IMAGERY ARE STILL SUGGESTING DRY AIR WILL WORK INTO CENTRAL ALABAMA ALOFT AND WE COULD STILL SEE SOME MIXING OUT OF THE CLOUDS CURRENTLY IN PLACE. IF THIS DOES OCCUR...A GOOD PORTION OF THE AREA COULD SEE SFC BASED CAPES IN THE 1000-1750 J/KG RANGE. WHEN COUPLED WITH INCREASING MID-LEVEL LAPSE RATES AND VEERING SURFACE WINDS...THIS COMBINATION COULD SPELL SOME FAIRLY LARGE HAIL AND POTENTIALLY DAMAGING WINDS WITH ANY STORM THAT TAPS INTO THAT ENERGY. IF YOU DO SEE CLEARING IN YOUR AREA AND THE SUN COMES OUT...THEN THAT WILL INCREASE YOUR CHANCE FOR A SEVERE THUNDERSTORM WATCH TO BE EXTENDED TO YOU AS THE ENVIRONMENT WILL RIPEN FOR SEVERE POTENTIAL THIS AFTERNOON AND EVENING. PROPER ENVIRONMENTAL CONDITIONS FOR SEVERE WEATHER ARE EXPECTED TO DECREASE AS WE MOVE TOWARDS THE MIDNIGHT HOUR TONIGHT. UPDATES ARE OUT. 27 && .AVIATION... 12Z TAF DISCUSSION. LOW CLOUDS JUST ABOUT ENCOMPASSING ALL TAF SITES. A FEW AREA WILL SEE A BRIEF WINDOW OF IMPROVEMENT BUT WENT WITH PREDOMINATE LOW MVFR CLOUDS NORTH AND IFR SOUTH THROUGH 15 TO 16Z. SHOWERS WILL CONTINUE TO DEVELOP THIS MORNING FOLLOWED BY THUNDERSTORMS AFTER MIDDAY AND THROUGH THE AFTERNOON HOURS. DUE TO THE UNSTABLE CONDITIONS THAT WILL BE IN PLACE...WENT AHEAD AND ADDED IN VCTS TO ALL TAFS THROUGH THE EVENING HOURS. CURRENT WINDS FROM THE SOUTHEAST WILL GRADUALLY SHIFT TO THE SOUTHWEST ON MONDAY AFTERNOON...AND COULD BECOME GUSTY UPWARDS TO 20 KNOTS AT TIMES. MODELS ARE HINTING THAT WE MAY HAVE A WINDOW FROM 21Z NORTH TO 3Z SOUTH IN WHICH CONDITIONS DRY AND IMPROVE TO VFR CEILINGS BETWEEN THE INITIAL LINE OF AFTERNOON THUNDERSTORMS AND THE FRONT ITSELF. GIVEN THE UNCERTAINTIES OF THE TIMING STUCK WITH PREDOMINATE MVFR AND VCTS UNTIL THE FRONT CAN ACTUALLY WORK THROUGH. MVFR LIKELY BEHIND THE FRONT UNTIL THE CLEARING CAN OCCUR TUESDAY MORNING. && .BMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$