000
FXUS64 KBMX 181802
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
102 PM CDT TUE JUN 18 2013

.UPDATE...
FOR 18Z AVIATION.

&&

.DISCUSSION...

THUNDERSTORMS ARE REDEVELOPING ACROSS THE AREA ALONG AND AHEAD OF
A SURFACE COLD FRONT THAT IS CURRENTLY DRAPED ACROSS
TENNESSEE...SOUTHWARD INTO MISSISSIPPI. THIS COLD FRONT WILL
CONTINUE TO MOVE TO THE SOUTHEAST THROUGHOUT THE DAY...WITH
THUNDERSTORMS CONTINUING TO MOVE ACROSS CENTRAL ALABAMA. ALTHOUGH
CLOUD COVER WILL KEEP TEMPERATURES ACROSS MOST OF THE AREA IN THE
MID TO UPPER 80S...INSTABILITY IS STILL GOING TO BE QUITE HIGH AND
THEREFORE THE ACTIVITY SHOULD BE ABLE TO SUSTAIN ITSELF. MODIFYING
THE 12Z KBMX SOUNDING FOR FORECAST CONDITIONS THIS
AFTERNOON...THERE WILL BE A RISK FOR SOME OF THE STRONGER STORMS
TO PRODUCE GUSTY WINDS. HOWEVER... CONFIDENCE ON WHEN AND WHERE
THEY MAY HAPPEN IS LOW AND THE STRONGER ACTIVITY SHOULD BE
ISOLATED. UPDATES ARE OUT.

73


&&

.AVIATION...
18Z TAF DISCUSSION.

EXPECT NUMEROUS SHOWERS/TSTORMS TO CONTINUE THRU THE AFTN/EVNG
AHEAD OF A COLD FRONT. SOME STORMS COULD PRODUCE GUSTY
WINDS AND BRIEF HEAVY RAINFALL...AND OF COURSE LIGHTNING WILL BE
PRESENT. WENT WITH A GENERAL SHRA VCTS FOR ALL SITES IN THE
NEAR TERM...BUT WILL AMEND TO ACCOUNT FOR MORE DIRECT IMPACTS FROM
TSRA. ACTIVITY SHOULD COME TO AN END ACROSS THE NORTH THIS
EVENING AS THE FRONT PUSHES SOUTHWARD. THE SOUTHERN TERMINALS
COULD SEE SOME SCT SHOWERS AND ISO TS INTO THE NIGHT BEFORE THE
FRONT PASSES THRU. WINDS WILL SHIFT FROM SW TO W JUST AHEAD OF THE
FRONT AND THEN TO THE NW BEHIND THE FRONT.

OTHER THAN TIMING OF TSRA TODAY THE OTHER FORECAST CHALLENGE WILL
BE CIG/VIS OVERNIGHT. MODELS DISAGREE ON WHETHER THERE WILL BE
STRATUS OR FOG OR NEITHER. BASED ON WHAT OCCURRED BEHIND THE FRONT
ACROSS THE MID MISSISSIPPI VALLEY LAST NIGHT...WILL LEAN TOWARD
THE DEVELOPMENT OF A LOW STRATUS DECK (IFR) ACROSS THE NORTH
BEHIND THE FRONT LATER TONIGHT. NOT EXTREMELY CONFIDENT BUT FEEL
THAT THIS IS THE MOST LIKELY OUTCOME ATTM. IF NO LOW CLOUDS
DEVELOP AND SKIES REMAIN MOSTLY CLEAR...THEN WITH LIGHT/CALM WINDS
FOG WILL BE LIKELY. COULD ALSO SEE SOME MVFR CIGS IN THE
SOUTH...BUT THERE SHOULD BE ENOUGH CLOUD COVER THERE TO PREVENT
ANY WIDESPREAD FOG CONCERNS. WILL MONITOR TRENDS CLOSELY FOR
POSSIBLE UPDATES/CHANGES TO THE OVERNIGHT FORECAST.

19

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$