000
FXUS62 KCAE 190813
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
413 AM EDT SUN MAY 19 2013

.SYNOPSIS...
WEAK UPPER LEVEL TROUGH WILL COVER THE REGION TODAY THROUGH TUESDAY.
THIS WILL BRING A HIGH CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
AREA TODAY WITH A MUCH SMALLER CHANCE FOR MONDAY AND TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REST OF THE OVERNIGHT PERIOD...WEAK SHORT WAVE CONTINUES TO MOVE
INTO THE REGION FROM THE WEST. INSTABILITY IS WEAK...SO JUST SHOWERS
ARE EXPECTED. THE CHANCES FOR RAIN WILL BE HIGHER IN THE WEST AT
ABOUT 60 PERCENT AND LOWER IN THE EAST AT 30-40 PERCENT. LOW
TEMPERATURES SHOULD BE IN THE MID 60S.

TODAY...WITH UPPER TROUGH OVER THE FORECAST AREA...CONDITIONS ARE
EXPECTED TO BE UNSETTLED. LIKED THE LOCAL LOCAL HIGH POPS LATER
TODAY. GENERALLY CARRIED 60 PERCENT POPS IN THE GRIDDED DATA FOR
MOST OF THE DAY BUT DID INCLUDE 80-90 PERCENT IN THE CENTRAL
MIDLANDS LATER THIS AFTERNOON ON TOWARD EVENING. WENT SHOWERS
THIS MORNING AND SHOWERS AND A CHANCE OF THUNDERSTORMS IN THE
AFTERNOON. EXPECT MAINLY MARGINAL INSTABILITY. MODELS VARY ON POPS
AND HIGH TEMPERATURES THIS AFTERNOON WHICH AFFECTS THE STABILITY
PARAMETERS AS WELL. GFS MOS GIVES 84 HIGH WITH MORE UNSTABLE
CONDITIONS WITH THE WARMER TEMPERATURES...WHEREAS NAM MOS GAVE
MORE STABLE CONDITIONS WITH A 79 HIGH. DECIDED ON A MODEL BLEND
WITH 81 HIGH AND JUST MARGINAL INSTABILITY. MODELS WERE A FEW
DEGREES TOO WARM FOR YESTERDAY. SPC HAS AREA IN SEE TEXT AND
THINK MAIN REASONING IS FOR WEAKER INSTABILITY. EXPECT A PRETTY
GOOD SKY COVER TODAY BUT IF THERE ARE MORE BREAKS GIVING MORE
SUNSHINE...THE ATMOSPHERE WILL BECOME MORE UNSTABLE OBVIOUSLY.

CONVECTIVE POTENTIAL FOR TODAY...

UPPER TROUGH WILL CONTINUE TO SLOWLY SHIFT EAST OVER OUR
REGION...WITH A MOIST ATMOSPHERE IN PLACE. HIGH POPS TODAY. GFS
INDICATING MORE INSTABILITY THAN NAM. TAKING A BLEND GENERALLY
INDICATES MODERATE INSTABILITY. LOW/MID LEVEL JET AND SHEAR WEAK.
WIDESPREAD SEVERE NOT EXPECTED...BUT ISOLATED SEVERE CELLS POSSIBLE.
06Z SPC DAY 1 OUTLOOK HAS OUR FA IN SEE TEXT.

VIL OF THE DAY 55

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
SOMEWHAT UNSETTLED WEATHER PATTERN FOR THE PERIOD. SURFACE FRONT
WILL REMAIN OFF TO THE NORTH OF THE AREA THROUGH THE PERIOD.
THE MAIN UPPER TROUGH IS PROGGED TO VERY SLOWLY TRACK EASTWARD
INTO TUESDAY. RIDGING BEHIND THE TROUGH MAY BE ABLE TO TAKE HOLD
ENOUGH BY TUESDAY TO BRING LOWER RAIN CHANCES. UNTIL THAT
TIME...EXPECTING HIGH CHANCE LIKELY POPS TONIGHT ESPECIALLY
THIS EVENING...THEN JUST CHANCE MONDAY. ACTIVITY SHOULD BECOME
MORE DIURNAL IN NATURE MONDAY NIGHT AND TUESDAY NIGHT WITH A
DECREASE IN MOISTURE. PLAN ON SLIGHT CHANCE EXCEPT WILL TAKE OUT
POPS LATE AT NIGHT AND EARLY IN THE MORNING. NOT EXPECTING
ANYTHING SEVERE WITH THE STORMS...JUST OCCASIONAL LIGHTNING AND
SOME HEAVIER RAINFALL. TEMPERATURES MONDAY AND TUESDAY WILL BE DE
PENDANT UPON CLOUD COVER AND RAINFALL. FOR NOW IT APPEARS AS IF
MOST AREAS SHOULD BE ABLE TO AT LEAST CLIMB INTO THE LOWER
80S...BUT WOULD NOT BE SURPRISED IF SOME AREAS THAT ARE IN THE
HEAVIER RAINFALL REGIONS REMAIN IN THE 70S MONDAY. TUESDAY SHOULD
SEE A LITTLE MORE SUNSHINE...SO HIGHS EXPECTED TO BE ABLE TO CLIMB
INTO THE MID AND UPPER 80S ONCE AGAIN. AS FOR OVERNIGHT
LOWS...READINGS MAINLY IN THE 60S.




&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MOVING INTO THE LONG TERM...THE REGION WILL BE UNDER THE INFLUENCE
OF AN UPPER RIDGE BRIEFLY ON WEDNESDAY...THEN THE RIDGE SLIDES
OFFSHORE AS A DEEPENING TROUGH TAKES HOLD ACROSS THE MISSISSIPPI
VALLEY REGION OF THE COUNTRY. RAIN CHANCES LOW ON WEDNESDAY...THEN
INCREASE SLIGHTLY INTO SATURDAY AS THE MAIN UPPER TROUGH MOVES
EASTWARD TOWARDS THE FORECAST AREA. EXPECT MAINLY DIURNAL SHOWERS
AND THUNDERSTORMS THROUGH THE PERIOD THOUGH. EXPECT TEMPERATURES
CLOSE TO OR JUST ABOVE CLIMATOLOGY THROUGH THE PERIOD.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
A WEAK UPPER TROUGH AND A MOIST ATMOSPHERE WILL PROMOTE GOOD CHANCES
OF SHOWERS AND POSSIBLE THUNDERSTORMS. CURRENT RADAR INDICATES
WEAKENING SHOWER ACTIVITY OVER THE W/NW FA SLOWLY SHIFTING EAST.
MORE SIGNIFICANT ACTIVITY OVER N GA...WHICH MAY NOT MAKE IT TO OUR
FA. GOOD COVERAGE OF MID AND HIGH LEVEL CLOUDINESS OVERNIGHT WILL
WORK AGAINST FOG DEVELOPMENT...BUT LATEST ARRAY OF MODELS SUGGEST
POSSIBILITY OF STRATUS DEVELOPING LATER TONIGHT. WILL INDICATE A
PERIOD OF LOWER CLOUDS...BUT KEEP CIGS MVFR DUE TO LIMITED
CONFIDENCE. BETTER CHANCE OF SHOWERS OR POSSIBLE THUNDERSTORMS
AFFECTING THE TERMINALS APPEARS WOULD BE GENERALLY LATE AFTERNOON TO
EARLY EVENING. WILL COMMUNICATE THAT WITH TEMPO SHRA GROUP.

EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH
WEDNESDAY. LATE NIGHT/EARLY MORNING FOG/STRATUS MAY BE POSSIBLE AS
WELL.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$