Flash Flood Warning 38, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
652 AM EST TUE DEC 22 2015

.SYNOPSIS...
WARM AND MOIST CONDITIONS SET UP TODAY AND LINGER THROUGH CHRISTMAS DAY.
UNSELTTLED WEATHER AND ABOVE NORMAL TEMPERATURES WILL CONTINUE OVER THE
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM...SOME FLOODING HAS DEVELOPED ACROSS THE AREA AFTER 2
ROUNDS OF HEAVY RAINFALL THIS MORNING. THE HEAVY RAIN IS SHIFTING
EASTWARD...BUT A COUPLE HOURS OF SPOTTY MODERATE RAINFALL WILL
CONTINUE. RUNOFF FROM THE EARLIER HEAVY RAIN WILL KEEP WATER LEVELS
HIGH ALONG AND SOUTH OF I-85 BUT CONDITIONS SHUD IMPROVE THRU THE
DAY AS ONLY SPOTTY LIGHT RAIN THRU THE AFTERNOON DUE TO THE SHORT
WAVE AND UPPER JET DRIVING THIS PRECIP MOVING EAST AS WELL. THERE
COULD ALSO BE A FEW TSRA ALONG THE SRN TIER OF THE CWFA THIS
AFTERNOON AS WEAK INSTABILITY DEVELOPS. CLOUDY SKIES WILL CONTINUE
THRU THE DAY AS WELL. HOWEVER...HIGHS WILL STILL REACH 10 TO 15
DEGREES ABOVE NORMAL.

SHOWERS WILL BECOME MORE WIDESPREAD AND INCREASE IN INTENSITY THIS
EVENING AS ANOTHER SHORT WAVE AND UPPER JET MOVE OVER THE AREA IN
THE MID LEVEL SWLY FLOW. THE LOW LEVEL FLOW BACKS AND INCREASES IN
SPEED AHEAD OF THESE WAVES. THIS WILL KEEP A STRONG FETCH OF GULF
MOISTURE OVER THE AREA AND PROVIDE STRONG UPSLOPE FLOW. QPF VALUES
OF 1 TO 2 INCHES WILL BE POSSIBLE...WITH THE HIGHEST AMOUNTS ALONG
AND NEAR THE BLUE RIDGE ESCARPMENT FROM THE NC/SC BORDER INTO NE GA.
THAT SAID...THE FCST GUIDANCE HAS BEEN QUITE VARIABLE FROM RUN TO
RUN REGARDING QPF. ANY SIGNIFICANT FLOOD THREAT WOULD HOLD OFF UNTIL
TONIGHT AS WELL. THEREFORE...WILL LET THE NEXT SHIFT LOOK AT THE
OBSERVED RAINFALL AND LATEST FCST GUIDANCE TO DETERMINE IF AND WHERE
A FLOOD WATCH WOULD BE NEEDED. ALONG WITH THE POTENTIAL FLOOD
THREAT...TSRA MAY DEVELOP ALONG AND SOUTH OF I-85 OVERNIGHT. THE
STRONG LOW LEVEL INVERSION OVER THE AREA TODAY WEAKENS SIGNIFICANTLY
TONIGHT. EVEN WITH THE VERY MOIST PROFILES...SOME WEAK INSTABILITY
SHUD DEVELOP OVERNIGHT. GIVEN THE STRONG SHEAR...WILL HAVE TO KEEP
AN EYE ON ANY STORMS THAT DEVELOP AND SEE IF ANY LINEAR FEATURES CAN
DEVELOP. HOWEVER...THIS REMAINS QUITE UNCERTAIN. LOWS TONIGHT WILL
BE 25 TO 30 DEGREES ABOVE NORMAL AND COULD THREATEN RECORDS FOR
HIGHEST MINIMUM TEMPERATURES.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AT 230 AM TUESDAY...ON WEDNESDAY MORNING AN UPPER RIDGE WILL BE OVER
THE WESTERN ATLANTIC...WHILE A BROAD UPPER TROUGH WILL COVER THE
WESTERN TWO THIRDS OF THE NATION...AND CHANNELED VORTICITY BETWEEN
THESE TO FEATURES MOVES NORTHEAST ACROSS THE SOUTHERN APPALACHIANS.
THE ATLANTIC RIDGE AMPLIFIES AND PROGRESSES BY THURSDAY...WHILE THE
TROUGH UPSTREAM BROADENS AND SPREADS ACROSS THE SOUTHERN
APPALACHIANS. THE RESULT IS THE CHANNELED VORTICITY FROM THE GULF
MOVES TO THE COAST. BY FRIDAY THE ATLANTIC RIDGE RETROGRESSES AND
FLATTENS...AND HEIGHTS RISE OVER GA AND THE CAROLINAS...WHILE THE
UPSTREAM TROUGH AMPLIFIES OVER THE ROCKIES. THIS LEADS TO THE BULK
OF UPPER LEVEL ENERGY BEING DIRECTED WELL TO OUR W AND N.

AT THE SURFACE...A WEAKENING COLD FRONT WILL BE OVER THE SOUTHERN
APPALACHIAN ON TUESDAY MORNING. ROBUST GULF AND ATLANTIC MOISTURE
AHEAD OF THIS SYSTEM WILL BE DIRECTED INTO NE GA AND THE WESTER
CAROLINAS. AS THE REMAINS OF THE BOUNDARY STALL OVER THE CAROLINAS
AND GA...LOW LEVEL FLOW WILL BACK TO THE SOUTH...INCREASING
ISENTROPIC UPGLIDE AND UPSLOPE FLOW ON TUESDAY NIGHT. ON WEDNESDAY
LOW LEVEL FLOW WILL VEER TO THE SE AHEAD OF A FRONT IN THE MS RIVER
VALLEY...DECREASING UPGLIDE AND UPSLOPE FLOW...BUT TIGHTENING
PRESSURE GRADIENT WILL ENSURE SIGNIFICANT GULF INFLOW PERSISTS. THE
PRESSURE GRADIENT RELAXES ON THURSDAY AND THURSDAY NIGHT AS THE
UPPER RIDGE SPREADS WEST...HOWEVER A MOIST PLUME REMAINS FRONT EH
GULF TO THE SOUTHERN APPALACHIANS AS THE FRONT REACHES THE MOUNTAINS
AND SLOWS TO A CRAWL.

PRECIPITATION AMOUNTS COULD REACH AS HIGH AS SEVEN INCHES IN THE
ELLICOT ROCK AREA WHERE NC...GA..AND SC MEET...WITH SUBSTANTIAL
TOTALS ACROSS MUCH OF THE FOOTHILLS AND PIEDMONT. SHEAR AND
INSTABILITY INCREASE O WEDNESDAY...SUPPORTING A MARGINAL CHANCE OF
SEVERE WEATHER...MAINLY DURING THE DAY. WINDS COULD BECOME RATHER
GUSTY AT HIGHER MOUNTAIN ELEVATIONS LATE WEDNESDAY INTO WEDNESDAY
NIGHT. TEMPERATURES WILL RUN WELL ABOVE NORMAL UNDER THE UPPER
RIDGE...ESPECIALLY MINIMUM TEMPERATURES DUE TO CLOUD COVER AND A
VERY MOIST ENVIRONMENT.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AT 230 AM TUESDAY...ON FRIDAY MORNING AND ATLANTIC UPPER RIDGE WILL
MAINTAIN A FOOTHILLS ON THE CAROLINAS AND GA...WHILE AN UPPER TROUGH
WILL AMPLIFY OVER THE ROCKIES. ON SATURDAY AN UPPER LOW WILL CLOSE
OFF AT THE BASED OD THIS TROUGH OVER AZ...REACHING W TX ON
SUNDAY...AND THE SOUTHERN PLAINS ON MONDAY...WHILE THE RIDGE HANGS
ON OVER OUR AREA.

AT THE SURFACE...A COLD FRONT WILL BE STALLED ALONG THE SOUTHERN
APPALACHIANS ON FRIDAY...WITH MODEST GULF INFLOW DIRECTED NE ALONG
THE BOUNDARY TO THE MOUNTAINS. ON SATURDAY HIGH PRESSURE CENTERED OVER
NEW ENGLAND WILL NOSE DOWN THE EAST COAST...WHILE GULF INFLOW
INCREASES TO THE WEST IN A TIGHTENING PRESSURE GRADIENT. THE EAST
COAST RIDGE BREAKS DOWN ON SUNDAY AS A COLD FRONT REACHES NEW
ENGLAND...WHILE ROBUST GULF INFLOW CONTINUES OVER THE GULF STATES. A
COLD FRONT MOVES ACROSS THE GULF STATES ON MONDAY...REACHING THE
SOUTHERN APPALACHIANS LATE IN THE DAY.

AT THIS TIME IT APPEARS THAT PRECIPITATION TOTAL OVER NE GA AND THE
WESTERN CAROLINAS WILL BE LIMITED FROM FRIDAY THROUGH MONDAY AS THE
BEST GULF INFLOW REMAINS TO OUR WEST...AND THEN WEAKENS BEFORE THE
FRONT FINALLY ARRIVES.  TEMPERATURES WILL REMAIN WELL ABOVE
NORMAL...BUT WITH A DOWNWARD TREND AS THE UPPER RIDGE WEAKENS SLOWLY.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AT KCLT...EXPECT THE BULK OF THE MORNING TO HAVE IFR CIGS...IF NOT
BRIEF LIFR...BEFORE INCREASING TO MVFR FOR THE AFTERNOON. WITH THE
HEAVY RAIN SHIFTING EASTWARD...ONLY BRIEF MVFR VSBY EXPECTED IN ANY
HEAVIER SHRA THIS MORNING. EXPECT HIGH BASED MVFR WITH VFR VSBY FOR
THE AFTERNOON WITH ISOLATED LIGHT SHRA CONDITIONS DETERIORATE THIS
EVENING AS LOW CLOUDS AND PRECIP RETURN. IFR CIGS AND MVFR VSBY
BECOME LIFR CIGS AND IFR VSBY IN HEAVIER RAIN OVERNIGHT. SOME LOW
LEVEL WIND SHEAR POSSIBLE THIS MORNING AS THE LOW LEVEL JET MOVES
OVER. OTHERWISE...LIGHT NLY WIND THIS MORNING BECOMES LIGHT SLY FOR
THE AFTERNOON. SSE WIND INCREASES IN SPEED THRU THE NITE.

ELSEWHERE...OVERALL SIMILAR TREND TO KCLT...EXCEPT WITH GENERALLY
WORSE CIGS THIS AFTERNOON. WINDS WILL ALSO BE MORE VARIABLE THRU THE
DAY AND EARLY EVENING.

OUTLOOK...DEEP LAYER MOISTURE ASSOCIATED WITH AN APPROACHING
COLD FRONT WILL CONTINUE TO OVERSPREAD THE REGION FROM THE W THRU
THURSDAY. EXPECT WIDESPREAD PRECIPITATION AT TIMES COUPLED WITH IFR
OR WORSE VSBY AND CIG RESTRICTIONS THROUGH THU. MODEST IMPROVEMENT
IS POSSIBLE ON FRIDAY...BUT MAY HOLD OFF UNTIL SAT.

CONFIDENCE TABLE...

            12-18Z        18-24Z        00-06Z        06-12Z
KCLT       HIGH  88%     HIGH  91%     HIGH  80%     HIGH  86%
KGSP       HIGH  90%     HIGH  97%     HIGH  93%     HIGH  98%
KAVL       MED   66%     HIGH  82%     HIGH  96%     HIGH  91%
KHKY       HIGH  88%     HIGH  94%     HIGH  96%     HIGH  98%
KGMU       MED   79%     HIGH  94%     HIGH  93%     HIGH  95%
KAND       HIGH  84%     HIGH  89%     HIGH  95%     HIGH  98%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION

&&

.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR WEDNESDAY DECEMBER 23...

 AVL   69    1933
 CLT   73    1990
 GSP   70    1970...1933

DAILY MAXIMUM TEMPERATURE RECORDS FOR THURSDAY DECEMBER 24...

 AVL   72    1955
 CLT   71    1982...1931
 GSP   71    1964

DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...

 AVL   67    1955...1944...1904
 CLT   77    1955
 GSP   78    1955

DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR WEDNESDAY DEC 23...

 AVL   59    1990
 CLT   63    1990
 GSP   61    1990

DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR THURSDAY DEC 24...

 AVL   54    1932
 CLT   56    1891
 GSP   55    1931

DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...

 AVL   55    1982
 CLT   62    1932
 GSP   56    1964

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

SYNOPSIS...JAT
NEAR TERM...RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH
CLIMATE...

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
627 AM EST TUE DEC 22 2015

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-231130-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-ALEXANDER-
IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-CATAWBA-
ROWAN-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION-
CALDWELL MOUNTAINS-GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-
MCDOWELL MOUNTAINS-EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-
GREATER RUTHERFORD-POLK MOUNTAINS-EASTERN POLK-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-GREATER OCONEE-
GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-
ANDERSON-ABBEVILLE-LAURENS-CHESTER-GREENWOOD-
627 AM EST TUE DEC 22 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT
NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

HEAVY RAIN IS EXPECTED LATE TONIGHT. FLOODING WILL BE POSSIBLE IN
SOME AREAS...ESPECIALLY IN THE SOUTHERN MOUNTAINS. A FLOOD WATCH
MAY BE ISSUED LATER TODAY.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

..WEDNESDAY...HEAVY RAIN POSSIBLE. A PERSISTENT WEATHER PATTERN
WITH WIDESPREAD HEAVY RAINFALL WILL PERSIST WEDNESDAY.
..THURSDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..FRIDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SATURDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SUNDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..MONDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.