Severe Thunderstorm Warning 118, NWS Columbia, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
805 PM EDT TUE JUL 14 2015

.SYNOPSIS...
AN UPPER RIDGE WILL REMAIN CENTERED OVER THE SOUTHERN PLAINS AND
LOWER MISSISSIPPI VALLEY...WHILE AN UPPER TROUGH REMAINS OVER THE
EAST COAST. A SERIES OF UPPER DISTURBANCES AND SURFACE BOUNDARIES
WILL SHIFT SE INTO THE REGION...AND PROMOTE SCATTERED
THUNDERSTORMS...SOME POSSIBLY SEVERE...AT TIMES THROUGH WEDNESDAY.
SOME DRIER AIR WILL ENTER THE REGION FOR THURSDAY AND FRIDAY AND
REDUCE THUNDERSTORM CHANCES.

&&

.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
A MESOSCALE CONVECTIVE COMPLEX EXTENDING INTO NORTH GEORGIA AND
WESTERN SOUTH CAROLINA WILL CONTINUE SHIFTING SOUTH-SOUTHEASTWARD
ACROSS THE REGION TONIGHT. LATEST RADAR TRENDS SUGGEST THAT THE
MAIN LINE OF STORMS WILL AFFECT THE CSRA WHILE AREAS FURTHER NORTH
WILL RECEIVE MAINLY SHOWERS. MODELS SHOW THE LINE WEAKENING SOME
ON THE SOUTHERN AND EASTERN EXTENT WITH THE LOSS OF DAYTIME
HEATING AND DECREASED INSTABILITY. HOWEVER...DYNAMICS ARE
STRONG...THE MAIN LINE IS BOWING...AND THE STORMS HAVE A HISTORY
OF PRODUCING DAMAGING WINDS. STORMS ARE EXPECTED TO EXIT THE CSRA
WITHIN THE 03Z TO 05Z TIME FRAME WITH SHOWERS LINGERING. OVERNIGHT
LOW TEMPERATURES ARE FORECAST IN THE MIDDLE TO UPPER 70S.

&&

.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
SOME SEVERE WEATHER CONCERNS CONTINUE WEDNESDAY.

UPPER RIDGE TO REMAIN CENTERED TO OUR WEST...WITH UPPER TROUGH OVER
THE EAST COAST. MODELS INDICATE UPPER TROUGH TO BEGIN WEAKENING AND
LIFTING TO THE NE DURING THE DAY. SURFACE FRONT APPEARS WILL ENTER
THE NORTHERN FA IN THE MORNING AND SHIFT TO THE SOUTHERN FA BY
AFTERNOON. AT THIS TIME...INSTABILITY PARAMETERS DO NOT LOOK QUITE
AS STRONG WEDNESDAY...AND LOW/MID LEVEL JET SPEEDS AND SHEAR VALUES
WEAKEN SOME. EXPECTED POSITION OF SURFACE FRONT/TROUGH COMBINED WITH
BEST MOISTURE ACROSS THE SOUTH...DIURNAL HEATING...AND POSSIBLE
INTERACTION WITH SEA BREEZE APPEARS WILL FAVOR POPS AND BEST SEVERE
THREAT ACROSS THE SOUTHERN HALF OF OUR FA WED AFTN/EVE. SPC DAY TWO
OUTLOOK HAS SLIGHT RISK SEVERE OVER OUR SOUTHERN FA...WITH MARGINAL
RISK CENTRAL.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
DRIER AIR AND HIGH PRESSURE BEHIND THE FRONTAL BOUNDARY WILL PUSH
INTO THE REGION FRIDAY. THIS WOULD SUGGEST ONLY A SLIGHT CHANCE OF
AFTERNOON CONVECTION ACROSS THE SOUTHERN FA. UPPER LEVEL HIGH
PRESSURE WILL SHIFT EASTWARD THROUGH SATURDAY. SOUTHERLY SURFACE
FLOW AND A WEAK SURFACE TROUGH MAY ALLOW FOR DIURNAL SHOWERS AND
THUNDERSTORMS THIS WEEKEND.

EXPECT TEMPERATURES TO SLIGHTLY RISE THROUGHOUT THE EXTENDED PERIOD
WITH HIGHS IN THE MID TO UPPER 90S FOR THE WEEKEND. A SURFACE
FRONT MAY MOVE INTO THE FA MID NEXT WEEK KEEPING A CHANCE FOR
SHOWERS AND THUNDERSTORMS IN THE FORECAST.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.

AN AREA OF CONVECTION CROSSING THE CAROLINA MOUNTAINS AND NORTHERN
GA AT 22Z WILL CONTINUE MOVING SOUTHWARD INTO THE TAF SITES THIS
EVENING. THIS CONVECTION COULD AFFECT AGS/DNL 02Z-07Z. CANNOT RULE
OUT OVERNIGHT CONVECTION ACROSS THE MIDLANDS...BUT PROBABILITY TOO
LOW TO INCLUDE AT THIS TIME. FOG POTENTIAL IS LOW FOR THE OVERNIGHT
DUE TO EXPECTED MIXING FROM THUNDERSTORMS AND A LOW LEVEL JET. A
COLD FRONT WILL CROSS THE AREA WEDNESDAY...SO THE CHANCE FOR SHOWERS
AND THUNDERSTORMS WILL CONTINUE.

EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN SCATTERED
SHOWERS AND THUNDERSTORMS SATURDAY AND SUNDAY.

&&

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

&&

99

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE COLUMBIA SC
328 AM EDT TUE JUL 14 2015

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-
150730-
LINCOLN-MCDUFFIE-COLUMBIA-RICHMOND-BURKE-LANCASTER-CHESTERFIELD-
MCCORMICK-NEWBERRY-FAIRFIELD-KERSHAW-EDGEFIELD-SALUDA-LEXINGTON-
RICHLAND-LEE-AIKEN-SUMTER-BARNWELL-ORANGEBURG-CALHOUN-CLARENDON-
BAMBERG-
328 AM EDT TUE JUL 14 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
GEORGIA AND CENTRAL SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT

AN ENHANCED SEVERE WEATHER THREAT IS EXPECTED TODAY AND TONIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A SLIGHT RISK OF SEVERE WEATHER SOUTHERN AREAS...WITH A MARGINAL
THREAT CENTRAL AREAS...WEDNESDAY AFTERNOON AND EVENING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE REQUIRED TODAY AND TONIGHT.