352 FXUS62 KCAE 282351 AFDCAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 751 PM EDT FRI MAR 28 2014 .SYNOPSIS... MOISTURE WILL BE HIGH AHEAD OF A SLOW MOVING FRONTAL SYSTEM. THE FRONT WILL MOVE THROUGH THE FORECAST AREA LATE SATURDAY. HIGH PRESSURE AND DRIER CONDITIONS WILL PREVAIL SUNDAY AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT WILL CONTINUE TO SUPPORT SHOWER ACTIVITY THROUGH THE EVENING. REGIONAL RADAR LOOP SHOWS AN EXTENSIVE AREA OF SHOWERS AND THUNDERSTORMS STRETCHING TO THE GULF. WATER VAPOR IMAGERY SHOWS A ROBUST SHORTWAVE ALONG THE GULF WHICH WILL REACH THE FORECAST AREA THIS EVENING. CLOUDINESS AND SHOWERS SHOULD LIMIT INSTABILITY ACROSS THE MIDLANDS AND CSRA THIS EVENING. EXPECT MAINLY SHOWERS INSTEAD OF THUNDERSTORMS ALTHOUGH CANNOT RULE OUT A RUMBLE OF THUNDER IN THE EASTERN PART OF THE FORECAST AREA. OBSERVATIONS SHOW A STRONG GRADIENT IN TEMPERATURES ACROSS THE FORECAST AREA. BREAKS IN CLOUD COVER AND WARM AIR ADVECTION HAVE ALLOWED TEMPERATURES TO RISE INTO THE UPPER 60S AND LOWER 70S ACROSS THE EASTERN MIDLANDS. FURTHER WEST...CLOUD COVER AND SHOWERS HAVE KEPT TEMPERATURES IN THE UPPER 50S AND LOWER 60S. TONIGHT...THE MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SUPPORT CONTINUED HIGH POPS TONIGHT. INSTABILITY APPEARS LIMITED TOWARD DAYBREAK AND FORECAST LI VALUES REMAIN POSITIVE UNTIL SATURDAY AFTERNOON. HAVE REDUCED CHANCE OF THUNDER TO ONLY ISOLATED. THE WARMER TEMPERATURE GUIDANCE APPEARS BETTER DUE TO CLOUDINESS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... SATURDAY...MOISTURE SHOULD BE HIGH AHEAD OF THE COLD FRONT SATURDAY. THE NAM INDICATES THE DEEPEST MOISTURE EARLY SATURDAY. THE GFS AND ECMWF SHOW THE DEEPEST MOISTURE DURING THE EARLY AFTERNOON AFTERNOON PERIOD. THE MODELS WERE MORE CONSISTENT WITH COLD FRONTAL PASSAGE LATE IN THE DAY OR EVENING. HAVE SLIGHTLY HIGHER POPS IN THE MORNING HOURS...SLIGHTLY LOWER TOWARD LATE MORNING...THEN INCREASING AGAIN AHEAD OF THE COLD FRONT. DIRECTIONAL WIND SHEAR WILL BE HIGHEST IN THE MORNING WITH MORE SPEED SHEAR DURING THE AFTERNOON AS H85 WINDS INCREASE TO 30 TO 40 KNOTS. THE BEST SHEAR AND INSTABILITY WITH LIS AROUND -3 WILL BE ACROSS THE SOUTHERN/EASTERN PORTION OF THE CWA...ALONG AND SOUTH OF THE I-20 CORRIDOR. SPC HAS ALL OF THE CWA OUTLOOKED FOR A SLIGHT RISK OF SEVERE THUNDERSTORMS WITH THE MAIN THREAT BEING DAMAGING WINDS. LEANED TOWARD THE LOWER END OF GUIDANCE CONSENSUS FOR AFTERNOON TEMPERATURES AND NEAR/JUST ABOVE FOR POPS. CONTINUED WITH SHOWERS/THUNDERSTORMS THROUGH SATURDAY. BY SATURDAY EVENING THE COLD FRONT WILL PUSH EAST OF THE AREA. MID/UPPER LEVEL TROUGH AXIS WILL PUSH ACROSS THE AREA EARLY SUNDAY. EXPECT DECREASING POPS FROM W TO E SATURDAY EVENING AND DRY CONDITIONS ON SUNDAY. HIGH PRESSURE WILL BUILD OVER THE AREA SUNDAY AFTERNOON THROUGH SUNDAY NIGHT. GUIDANCE IN GOOD AGREEMENT WITH TEMPERATURES...SO STAYED CLOSE TO CONSENSUS. EXPECT CHILLY TEMPERATURES SUNDAY NIGHT WITH LOWS IN THE MID/UPPER 30S...COULD SEE SOME SCATTERED FROST AND AN ADVISORY MAY BE NEEDED. WILL MONITOR OVER THE NEXT COUPLE OF DAYS. && .LONG TERM /MONDAY THROUGH FRIDAY/... THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE IN THE PERIOD AHEAD OF A COLD FRONT. WARMER TEMPERATURES SHOULD OCCUR BEGINNING MONDAY AS THE HIGH SHIFTS EASTWARD AND THE AIR MASS CONTINUES TO MODIFY. THE GFS...ECMWF... AND EKD MOS SUPPORT HIGHS IN THE UPPER 70S TO AROUND 80 TUESDAY THROUGH THURSDAY. SLIGHTLY COOLER BY THE END OF THE WEEK...FRIDAY...WITH INCREASING CLOUDS AND THE CHANCE OF RAIN. && .AVIATION /00Z SATURDAY THROUGH THURSDAY/... WIDESPREAD SHOWERS AFFECTING THE TAF SITES AT THE BEGINNING OF THE TAF PERIOD SHOULD MOVE EAST THROUGH 02Z AS AN UPPER LEVEL DISTURBANCE MOVES OUT OF THE AREA. STILL COULD SEE SCATTERED SHOWERS OVERNIGHT. MODELS INDICATE IFR CONDITIONS OVERNIGHT GIVEN ABUNDANT LOW LEVEL MOISTURE. LOW CONFIDENCE ON TIMING OF IFR CONDITIONS. MVFR CONDITIONS EXPECTED TO RETURN AROUND 16Z SATURDAY AS SOUTHERLY WINDS INCREASE AHEAD OF THE APPROACHING COLD FRONT. THERE SHOULD BE AN AREA SHOWERS/TSTMS TO CROSS THE TAF SITES DURING THE AFTERNOON AHEAD OF THE COLD FRONT. THE COLD FRONT WILL CROSS THE TAF SITES AROUND THE END OF THE TAF PERIOD. EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS AREA EXPECTED IN THE WAKE OF THE FRONT SATURDAY NIGHT INTO SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$