Area Forecast Discussion
Issued by NWS Columbia, SC

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000 FXUS62 KCAE 020700 AFDCAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 300 AM EDT TUE SEP 2 2014 .SYNOPSIS... HIGH PRESSURE WILL EXTEND INTO THE FORECAST AREA FROM THE ATLANTIC THROUGH THURSDAY. A PERSISTENT UPPER RIDGE WILL HELP MAINTAIN THE HOT TEMPERATURES. && .NEAR TERM /THROUGH TONIGHT/... NOCTURNAL COOLING AND HIGH LOW-LEVEL MOISTURE SHOULD RESULT IN AREAS OF STRATUS AND FOG EARLY THIS MORNING. HOWEVER...WEAK INSTABILITY AND DEEP MOISTURE SHOULD HELP PREVENT DENSE FOG. THE SURFACE RIDGE WILL REMAIN EAST AND SOUTH OF THE FORECAST AREA WITH WEAK LEE-SIDE TROUGHING IN THE AREA. STRONG HEATING PLUS CONVERGENCE INTO THE TROUGH SHOULD HELP SUPPORT THUNDERSTORMS. THUNDERSTORM COVERAGE SHOULD BE LIMITED BY THE UPPER RIDGING AND SLOW STORM MOVEMENT. THE HIGH-RESOLUTION MODELS DISPLAY SCATTERED COVERAGE. THE GUIDANCE CONSENSUS SUPPORT POPS AROUND 30 PERCENT. PRECIPITABLE WATER WILL BE AROUND 2 INCHES. THIS MOISTURE PLUS A SLOW STORM MOTION SIGNALS A POSSIBILITY OF LOCALIZED FLOODING. THE MODELS INDICATE STRONG INSTABILITY. THE NAM HAS SURFACE-BASED LI/S NEAR -8 TODAY. THIS INSTABILITY PLUS HEAVY PRECIPITATION LOADING INDICATES A POSSIBILITY OF DAMAGING WIND WITH THE THUNDERSTORMS. RECENT VERIFICATION FAVORS THE WARMER TEMPERATURE GUIDANCE. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... THE SURFACE RIDGING EAST AND SOUTH OF THE FORECAST AREA WILL CONTINUE TO DOMINATE. A WEAKENING FRONT APPROACHING FROM THE NORTHWEST SHOULD STALL BEFORE REACHING THE AREA. HOWEVER...STRONG HEATING WITH DEEP MOISTURE PLUS SOME CONVERGENCE ASSOCIATED WITH LEE-SIDE TROUGHING SHOULD HELP SUPPORT THUNDERSTORMS. COVERAGE SHOULD BE LIMITED BECAUSE OF CONTINUED UPPER-LEVEL RIDGING AND SLOW STORM MOVEMENT. THE GUIDANCE CONSENSUS SUPPORTS POPS AROUND 30 PERCENT. HEAVY RAIN MAY OCCUR WITH ANY THUNDERSTORMS BECAUSE OF SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2 INCHES. RECENT VERIFICATION FAVORS THE WARMER TEMPERATURE GUIDANCE. && .LONG TERM /THURSDAY THROUGH MONDAY/... THE GFS AND ECMWF SHOW RIDGING EXTENDING INTO THE AREA FROM THE ATLANTIC DOMINATING EARLY IN THE MEDIUM-RANGE PERIOD. SUFFICIENT MOISTURE COMBINED WITH HEATING SHOULD SUPPORT SCATTERED MAINLY DIURNAL THUNDERSTORMS. THE MODELS DISPLAY A COLD FRONT IN THE AREA SUNDAY AND MONDAY SUPPORTING AN INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS. THE GFS...ECMWF...AND EKD MOS HAVE POPS 20 TO 30 PERCENT EARLY INCREASING TO 30 TO 40 PERCENT BY THE END OF THE PERIOD. ABOVE NORMAL TEMPERATURES SHOULD LOWER TO NEAR NORMAL TOWARD THE END OF THE PERIOD BECAUSE OF INCREASED CLOUDINESS ASSOCIATED WITH THE FRONT. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS THROUGH THE NEXT SEVERAL HOURS WITH MVFR/IFR POSSIBLE DURING THE EARLY MORNING AND AROUND SUNRISE. CONVECTION HAS DISSIPATED ACROSS THE AREA EARLY THIS MORNING. MAIN CONCERN FOR THE TAF PERIOD REMAINS FOG AND STRATUS THREAT...HOWEVER MUCH OF THE THREAT IS DIMINISHED BY CONVECTIVE DEBRIS ACROSS THE REGION. AS SUCH HAVE REMAINED WITH IFR CONDITIONS FOR AGS AND MVFR ELSEWHERE. FOG AND STRATUS WHICH DEVELOP WILL ERODE WITH SUNRISE AND MIXING WITH THE REMAINDER OF THE PERIOD VFR. EXPECT CUMULUS TO AGAIN DEVELOP DURING THE LATE MORNING THROUGH AFTERNOON HOURS...CONFIDENCE REMAINS TOO LOW TO INCLUDE MENTION OF CONVECTION ATTM. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT AND EARLY MORNING STRATUS AND FOG. SCATTERED MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS MONDAY THROUGH FRIDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$

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