Special Weather Statement, NWS Columbia, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
401 AM EDT THU AUG 6 2015

.SYNOPSIS...
AN UPPER TROUGH AND INCREASING MOISTURE WILL LEAD TO GREATER
PRECIPITATION CHANCES TODAY INTO FRIDAY...FOLLOWED BY DRIER AIR
RETURNING FOR THE WEEKEND. A FRONT MAY AFFECT THE REGION EARLY
NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPPER TROUGH...CURRENTLY WORKING EAST INTO THE OHIO AND MID
MISSISSIPPI VALLEYS...WILL CONTINUE TO TRACK EAST TO THE
APPALACHIANS BY LATE TONIGHT...WITH INCREASING ATMOSPHERIC
MOISTURE STREAMING INTO OUR REGION AHEAD OF IT...WITH PRECIPITABLE
WATER VALUES PROGGED TO INCREASE TO NEAR OR JUST ABOVE 2 INCHES.
SOME UPPER IMPULSES AHEAD OF THE MAIN UPPER TROUGH APPEAR WILL
AFFECT OUR REGION TODAY. SOME HIGH RESOLUTION MODEL OUTPUT
INDICATING CONVECTION COULD BEGIN RELATIVELY EARLY TODAY...WITH
DECENT AREAL COVERAGE POSSIBLE. THINK GOOD CHANCE POPS IN ORDER.

THOUGH SOME STABILIZATION EXPECTED TONIGHT DUE TO RAIN COOLING
COULD REDUCE AREAL COVERAGE OF CONVECTION...THINK UPPER LIFT
AHEAD OF THE APPROACHING UPPER TROUGH AND LOW LEVEL CONVERGENCE
ALONG AND AHEAD OF THE SURFACE BOUNDARY COMBINED WITH HIGH
MOISTURE IN PLACE WILL PROVIDE A CONTINUED THREAT OF
PRECIPITATION TONIGHT...ESPECIALLY NORTH.

MODERATE INSTABILITY TODAY WITH INCREASING SHEAR LATE AFTERNOON
THROUGH OVERNIGHT HOURS. MID LEVEL DRY AIR IN PLACE THOUGH NOT QUITE
AS MUCH AS WEDNESDAY BUT STILL A BIT OF A LOW LEVEL INVERTED V
FEATURE IN FORECAST SOUNDING. MID LEVEL SHORTWAVE TROUGH WILL
APPROACH DURING PEAK HEATING WITH BEST PVA DURING 21Z-06Z. PWAT
VALUES RISE TO AROUND 2 INCHES BY THIS EVENING SUPPORTING POSSIBLE
HEAVY RAIN THREAT ALTHOUGH STORMS SHOULD HAVE BETTER MOVEMENT
TODAY WITH INCREASED WIND SHEAR. SOME BROKEN ORGANIZED LINES COULD
DEVELOP AND SPC HAS OUTLOOKED THE REGION IN SLIGHT RISK. STRONG
TO SEVERE STORMS WILL HAVE POTENTIAL FOR DAMAGING WINDS WITH
STRONG DCAPE AROUND ~1300 J/KG AND WINDEX VALUE OF 58.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
MODEL CONSENSUS HAS UPPER TROUGH AND SURFACE BOUNDARY ACROSS THE
WESTERN CAROLINAS EARLY...MOVING EAST INTO THE CENTRAL CAROLINAS
BY MIDDAY AND TO THE COASTAL PLAIN BY AFTERNOON...WHILE SURFACE
LOW DEVELOPS AND TRACKS EAST ACROSS NC. BAND OF BEST POPS EXPECTED
TO WORK EAST ACROSS THE FORECAST AREA (FA) WITH THE FRONT MAINLY
EARLY...WITH BEST POPS SHIFTING TO THE EAST FA BY AFTERNOON. DRIER
AIR IS EXPECTED TO WORK INTO THE WEST FA/CSRA DURING THE
AFTERNOON.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
UPPER TROUGH AND BEST MOISTURE WILL SHIFT OFFSHORE BY EARLY
SATURDAY...WITH A DRIER ATMOSPHERE FOR OUR FA SAT/SUN. WEAK COOL
ADVECTION BEHIND THE FRONT AND DEPARTING LOW EXPECTED TO KEEP
TEMPS DOWN TO NEAR OR JUST BELOW CLIMO SAT. MODELS INDICATE UPPER
RIDGE WILL SHIFT BACK TO THE WEST SOME...WITH UPPER TROUGH
DEEPENING OVER THE E CONUS...EARLY TO MID NEXT WEEK. THIS ALONG
WITH SOME EXPECTED INCREASE IN MOISTURE AND INDICATIONS OF A
POSSIBLE FRONT SUGGESTS TREND TOWARDS INCREASING POPS. GENERALLY
ACCEPTED BLEND OF GUIDANCE.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
GENERALLY EXPECTING VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD
EXCEPT NEAR OR IN THUNDERSTORMS. CONVECTION HAS DIMINISHED FOR THE
NIGHT ACROSS THE MIDLANDS AND A 20 KNOT LOW LEVEL JET SHOULD BE
SUFFICIENT TO LIMIT FOG DEVELOPMENT ALONG WITH WEAK ATMOSPHERIC
INSTABILITY. ISOLATED MVFR VSBYS IN FOG POSSIBLE WHERE HEAVY RAIN
FELL AND THEREFORE HAVE INCLUDED A TEMPO GROUP AT CUB 09Z-13Z.
OTHERWISE...HRRR INDICATING POSSIBLE MVFR CIGS AT AGS/DNL JUST
AFTER DAWN THURSDAY. VFR CONDITIONS SHOULD BE COMMON ACROSS THE
REGION AFTER 14Z WITH INCREASING SOUTHWESTERLY WINDS.

CONVERGENCE INTO A SURFACE TROUGH AND AN INCREASE IN
MOISTURE AND INSTABILITY ASSOCIATED WITH A MID-LEVEL SHORTWAVE
TROUGH PLUS STRONG DIURNAL HEATING SHOULD SUPPORT THUNDERSTORMS
THURSDAY. HAVE NOT INCLUDED TSRA IN THE FORECAST YET DUE TO TIMING
UNCERTAINTY BUT CHANCES SHOULD INCREASE AFTER 20Z.

EXTENDED AVIATION OUTLOOK...A SURFACE TROUGH AND UPPER-LEVEL
TROUGH WILL HELP SUPPORT SCATTERED TO NUMEROUS THUNDERSTORMS AND
ASSOCIATED RESTRICTIONS THURSDAY NIGHT AND FRIDAY. OTHERWISE...
MVFR OR IFR CONDITIONS POSSIBLE IN LATE NIGHT AND EARLY MORNING
FOG.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE COLUMBIA SC
407 AM EDT THU AUG 6 2015

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-070815-
LINCOLN-MCDUFFIE-COLUMBIA-RICHMOND-BURKE-LANCASTER-CHESTERFIELD-
MCCORMICK-NEWBERRY-FAIRFIELD-KERSHAW-EDGEFIELD-SALUDA-LEXINGTON-
RICHLAND-LEE-AIKEN-SUMTER-BARNWELL-ORANGEBURG-CALHOUN-CLARENDON-
BAMBERG-
407 AM EDT THU AUG 6 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MIDLANDS OF SOUTH CAROLINA
AND THE CENTRAL SAVANNAH RIVER AREA OF GEORGIA.

.DAY ONE...TODAY AND TONIGHT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS...MAINLY THIS
AFTERNOON AND EVENING. SOME OF THE STROMS WILL BE CAPABLE OF
PRODUCING STRONG DAMAGING WIND GUSTS...AND LOCALLY HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
131 PM EDT THU AUG 6 2015

SCZ015-020-021-061830-
NEWBERRY-FAIRFIELD-LANCASTER-
131 PM EDT THU AUG 6 2015

...STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN FAIRFIELD...
LANCASTER AND NORTHERN NEWBERRY COUNTIES...

AT 128 PM EDT...STRONG THUNDERSTORMS OVER NORTHWEST NEWBERRY CHESTER
AND NORTHERN FAIRFIELD COUNTIES WERE MOVING NORTHEAST AT 25 MPH.

WIND GUSTS OF 35 TO 45 MPH ARE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
NEWBERRY...LANCASTER...WAXHAW...WHITMIRE...ELGIN...HEATH SPRINGS...
IRWIN...BLACKSTOCK...FISHING CREEK RESERVOIR AND LANCASTER MILL.

LAT...LON 3507 8090 3493 8078 3482 8080 3482 8061
      3464 8045 3422 8178 3443 8174 3453 8164
      3449 8149 3450 8142 3457 8142 3455 8087
      3465 8089 3470 8086 3483 8090 3484 8087
      3493 8086 3501 8091
TIME...MOT...LOC 1728Z 240DEG 49KT 3449 8157