964 FXUS64 KHUN 181740 AAA AFDHUN AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE HUNTSVILLE AL 1240 PM CDT TUE JUN 18 2013 .UPDATE... FOR 18Z TAFS && .DISCUSSION... /ISSUED 1037 AM CDT TUE JUN 18 2013/ PREVIOUS RAINFALL OVER THE LAST TWO DAYS OF 3 TO 5 INCHES IN JACKSON...MARSHALL...AND DEKALB COUNTIES COULD CAUSE SOME LOCALIZED FLASH FLOODING ISSUES THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. HYDRO CONCERNS WILL CONTINUE TO BE MONITOR THROUGH THE AFTERNOON. OTHERWISE...A COLD FRONT CONTINUES TO SLOWLY SLIDE SOUTHEAST AND CURRENTLY EXTENDS FROM JUST EAST OF SEWANEE TENNESSEE TO AROUND MOULTON ALABAMA. SCATTERED SHOWERS AND STORMS HAVE DEVELOPED ALONG AND AHEAD OF THIS FRONT WHERE SOME WEAK INSTABILITY STILL EXIST WITH LAPS DATA SHOWING LI VALUES AROUND -4 AND CAPE AROUND 300 J/KG. ABUNDANT MOISTURE IS STILL IN PLACE IN THE ATMOSPHERIC COLUMN. THIS CAN BE SEEN IN BMX AND EVEN NASHVILLE'S 12Z SOUNDINGS. THIS WILL KEEP THE THREAT FOR HEAVIER DOWNPOURS...ESPECIALLY WITH ANY THUNDERSTORM DEVELOPMENT. A FEW STORMS COULD BE STRONG PRODUCING HEAVY RAINFALL AND GUSTY WINDS TO 40 MPH. THIS WILL CONTINUE THROUGH THE AFTERNOON HOURS...ESPECIALLY IN OUR SOUTHEASTERN COUNTIES AHEAD OF THE STRONGER FORCING ASSOCIATED WITH THE MAIN FRONTAL BOUNDARY. A SECOND POST FRONTAL TROUGH EXISTS OVER NORTHERN TENNESSEE. THIS COULD HELP TO INITIATE SCATTERED SHOWERS AND STORMS LATER THIS AFTERNOON ACROSS NORTHWESTERN ALABAMA AND IT PUSHES SOUTHEAST BEHIND THE COLD FRONT. THEREFORE BELIEVE MAIN BREAKS IN CLOUD COVER WILL BE THIS MORNING...AS MORE CONCENTRATED CLOUD COVER PUSHES BACK IN WITH THE POST FRONTAL TROUGH AXIS. DUE TO CLOUD COVER AND EXPECTED PRECIPITATION LOWERED HIGH TEMPERATURES INTO THE MID TO UPPER 70S...EXCEPT IN NORTHWESTERN ALABAMA WHERE HIGHS COULD REACH THE LOWER 80S DUE TO SOME LATE INSOLATION. KTW && .AVIATION... FOR 18Z TAFS... MVFR CIGS HAVE DEVELOPED OVER BOTH TAF SITES WITH CIGS DROPPING TO BETWEEN 2000 AND 3000 FEET. ALTHOUGH SOME HEATING HAS OCCURRED WITH SOME BREAKS IN CLOUDS...BELIEVE MVFR CIGS WILL BECOME MORE WIDESPREAD AND PERSISTENT THROUGH MUCH OF THE AFTERNOON ASSOCIATED WITH A PASSING UPPER LEVEL DISTURBANCE. BASED ON UPSTREAM CIGS ASSOCIATED WITH THIS FEATURE...BRIEF IFR CIGS JUST BELOW 2000 FEET LOOK POSSIBLE...SO INCLUDED THIS AS A TEMPO GROUP BETWEEN 18/18Z AND 18/21Z AT KMSL AND 18/19Z AND 18/23Z AT KHSV. BY 19/03Z AT KMSL AND 19/04Z AT KHSV...BELIEVE VFR CONDITIONS WILL RETURN. MFVR VSBYS ARE POSSIBLE AROUND 19/12Z DUE TO FOG DEVELOPMENT. ONCE FOG DISSIPATES VFR CONDITONS WILL RETURN AND PREVAIL. KTW && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT WEATHER.GOV/HUNTSVILLE.