000
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.
&&

$$

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