948 FXUS64 KHUN 281544 AAB AFDHUN AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE HUNTSVILLE AL 1044 AM CDT FRI MAR 28 2014 .UPDATE... MORNING UPDATE && .DISCUSSION... THE LARGE MCS IS MOVING OUT OF MS AND CONTINUING THROUGH CENTRAL/SOUTHERN AL PRODUCING HEAVY RAINFALL AND EMBEDDED THUNDERSTORMS NEAR THE COAST. CLOSER TO HOME...A PREFRONTAL TROUGH WAS NOTED IN ANALYZED OBS AND ASSOCIATED PRECIPITATION SEEN ON RADAR EXTENDING FROM MIDDLE TENNESSEE THROUGH OUR CWA THIS MORNING. TEMPS THIS MORNING HAVE ALREADY CLIMBED NEAR 60 AND DEW POINTS ARE IN BETTER SHAPE TODAY WITH THE PLETHORA OF GULF MOISTURE. MAIN FORECAST CHANGE WAS TO DECREASE THE POPS FOR TODAY. SCATTERED SHOWERS ARE STILL POSSIBLE THIS AFTERNOON AND EVENING BUT THE GREATEST CHANCE OF PRECIPITATION IS LATER TONIGHT. THE MAIN AXIS OF RAIN HAS SHIFTED SOUTH AND MOST OF THE MOISTURE TO PRODUCE THE RAINFALL PREVIOUSLY EXPECTED FOR TODAY IS BEING INTERCEPTED BY THE MCS. STILL EXPECTING DEVELOPMENT OVERNIGHT AS THE COLD FRONT APPROACHES. ALSO UPDATED THE HOURLY WINDS AND DEWPOINTS TO ACCOUNT FOR CURRENT TRENDS. JMS && .AVIATION... /ISSUED 654 AM CDT FRI MAR 28 2014/ FOR 12Z TAFS...-RA HAS LARGELY CLEARED KHSV/KMSL BUT MVFR CEILINGS PERSIST. REGARDLESS OF RAIN...THESE MVFR CEILINGS ARE NOT GOING ANYWHERE...AS IFR CEILINGS APPEAR UNLIKELY UNTIL EVENING. THEY COULD ARRIVE SOONER AS SHRA DEVELOP THIS AFTN BUT CONFIDENCE IS LOW. CONFIDENCE IS HIGHER IN TSRA TIMING (02-07Z) TONIGHT...THOUGH ISLTD TSRA ARE POSSIBLE FROM LATE AFTN ALL THE WAY THRU 08-09Z. KEPT TSRA CEILINGS AS IFR FOR NOW THOUGH THEY COULD EASILY CRASH FURTHER TO 500FT OR LESS. OCNL SHRA AND LOW CEILINGS WILL CONTINUE UNTIL MID- MORNING SAT. BCC && .PREV DISCUSSION... /ISSUED 311 AM CDT FRI MAR 28 2014/ AT 08Z...AREA 88-DS AND IR SATELLITE IMAGERY BOTH INDICATED THAT A LARGE AREA OF SHOWERS WITH EMBEDDED STORMS WAS MOVING NORTHEAST OUT OF EAST CENTRAL MISSISSIPPI INTO CENTRAL AND NORTH ALABAMA. A SHORT WAVE WILL CONTINUE TO MOVE NORTHEAST OUT OF EAST CENTRAL MISSISSIPPI TOWARD THE FORECAST AREA THIS MORNING. THIS UPPER LEVEL SYSTEM WAS COMBINING WITH RAPIDLY INCREASED GULF OF MEXICO MOISTURE TO PROVIDE FOR NUMEROUS SHOWERS AND EMBEDDED STORMS MOVING NORTHEAST TOWARD THE FORECAST AREA EARLY THIS MORNING. THE SURFACE ANALYSIS AT 08Z SHOWED THAT THE COLD FRONT WAS EXTENDING SOUTHWEST FROM JUST EAST OF ST. LOUIS MISSOURI...TO JUST WEST OF LITTLE ROCK ARKANSAS. THE SHORT TERM MODELS ARE FAIRLY SIMILAR INVOLVING KEEPING A STEADY STREAM OF SHOWERS AND STORMS MOVING TOWARD AND THROUGH THE FORECAST AREA. MODEL PWAT VALUES ARE STILL RANGING FROM ONE TO 1.25 INCHES. WILL CONTINUE WITH NEARLY CATEGORICAL POPS...ESPECIALLY FOR AREAS SOUTH OF THE TENNESSEE RIVER FOR THE MORNING HOURS. THE GFS MODEL IS LIKELY DOING A BETTER JOB IN HANDLING THE DRIER AIR THAT IS FILTERING SOUTHEAST INTO THE REGION BEHIND THE SHORT WAVE. THIS SOLUTION IS COMPARED TO THE WETTER SOLUTION OF THE NAM MODEL. THE MODELS CONTINUE TO INITIALLY OCCLUDE THE COLD FRONT AND DEVELOP ANOTHER AREA OF LOW PRESSURE ALONG THE WEAKENING COLD FRONT BY TONIGHT. INVOLVING HIGH TEMPS TODAY...HAVE GONE MORE IN LINE WITH GFS TEMP GUIDANCE FOR TODAY. ANOTHER SHORT WAVE AT 500 MILLIBARS WILL MOVE NORTHEAST OUT OF ARKANSAS TONIGHT INTO THE FORECAST AREA ALONG THE COLD FRONTAL BOUNDARY. FORECAST SOUNDINGS INDICATE THAT THERE WILL BE MORE UNSTABLE AIR ACROSS THE FORECAST AREA TONIGHT...AS EVIDENCED BY LIFTED INDICES BEING AT AROUND -5 BY TONIGHT AND CAPE VALUES INCREASING TO ABOVE 1000 J/KG AND PWAT VALUES UP TO AROUND 1.5 INCHES. HAVE GONE WITH BASICALLY CATEGORICAL POPS FOR TONIGHT AND INTO SATURDAY MORNING. WILL TREND BACK THE PRECIP CHANCES ON SATURDAY MORNING...AS THE SHORT WAVE AND ADJOINING SURFACE COLD FRONT WILL BE GENERALLY EAST OF THE FORECAST AREA BY BETWEEN 12Z AND 18Z SATURDAY. A LARGE AREA OF HIGH PRESSURE WILL THEN BUILD SOUTHEAST INTO THE TENNESSEE VALLEY REGION DURING THE AFTERNOON ON SATURDAY. THE BACK SIDE OF THE RIDGE AXIS WILL MOVE OVER THE AREA BY 00Z MONDAY. THROUGH MONDAY AND TUESDAY...WILL CONTINUE WITH A COMPROMISE BETWEEN THE GFS AND ECMWF MODELS INVOLVING TEMPS. A WEAKENING COLD FRONT IS EXPECTED TO OCCLUDE NEAR THE FORECAST AREA BY TUESDAY. ANOTHER STRONGER COLD FRONT IS EXPECTED TO MOVE SOUTHEAST THROUGH THE SOUTHERN PLAINS INTO THE FORECAST AREA BY 12Z THURSDAY. WILL MAINTAIN THE CURRENT PRECIP CHANCES INTO THE MID AND LATTER PART OF THE FORECAST. HAVE COMPROMISED BETWEEN THE GFS AND ECMWF MODELS INVOLVING TEMPS THROUGH THE END OF THE UPCOMING FORECAST. TT && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT WEATHER.GOV/HUNTSVILLE.