Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
207 PM EDT TUE MAR 20 2012

.SYNOPSIS...
A WARM AND MOIST AIR MASS WILL DOMINATE THE REGION OVER THE
NEXT SEVERAL DAYS. A COLD FRONT IS EXPECTED TO PUSH EAST ACROSS THE
CAROLINAS AND NORTHEAST GEORGIA OVER THE WEEKEND...FOLLOWED BY
SOMEWHAT COOLER AND DRIER HIGH PRESSURE SUNDAY INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 145 PM...A HIGHLY AMPLIFIED PATTERN REMAINS IN PLACE THIS
AFTERNOON...WITH A CUTOFF LOW PRESSURE SYSTEM MOVING INTO W TX...AND
A DEEP RIDGE OVER THE APPALACHIANS. SCATTERED AFTN CONVECTION HAS
FIRED MAINLY NEAR THE NC BLUE RIDGE...WHERE LOW LEVEL CONVERGENCE
AND UPSLOPE FLOW ARE PROVIDING THE BEST FORCING...AND WHERE LAPSE
RATES ALOFT ARE THE STEEPEST. THIS ACTIVITY COULD SPREAD ISOLD TO
SCT COVERAGE INTO THE FOOTHILLS AND PIEDMONT THROUGH THE EVENING ON
THE STRENGTH OF ANY OUTFLOWS. THERE IS LITTLE STEERING FLOW UP THE
SOUNDINGS AND ANY TSTMS WILL PRODUCE LOCALLY VERY HEAVY RAINFALL.
SFC BASED CAPE VALUES OF 1000 TO 2000 J/KG ACROSS THE REGION SHOULD
YIELD SOME RATHER STRONG STORMS...WITH ISOLATED SEVERE POSSIBLE FROM
ANY CELLS EXHIBITING 55 DBZ TO AROUND 22 KFT.

AFTER THE MAINLY DIURNAL CONVECTION WANES A LITTLE BY
MIDNIGHT...COVERAGE OF SHOWERS AND ISOLD TSTMS MAY INCREASE AGAIN
OVERNIGHT ACROSS NRN SECTIONS WITH A LIGHT SE UPSLOPE INTO THE NC
BLUE RIDGE...AND ALSO FROM A VORT MAX MOVING SWD JUST E OF THE UPPER
RIDGE. COVERAGE ACROSS THE INTERSTATE 77 CORRIDOR MAY THEN EXPAND
THROUGH WED AS BETTER DEEP LAYER DPVA MOVES SWD ACROSS CENTRAL NC
AND SC. MID LEVEL TEMPERATURES INCREASE A LITTLE ON WED...SO SFC
BASED CAPE VALUES WILL LIKELY BE LESS THAN TUE. HOWEVER...STORMS
WILL CONTINUE TO BE SLOW MOVERS AND POSE AN ISOLATED HYDRO THREAT.
TEMPERATURES WILL REMAIN ABOUT 15 DEGREES ABOVE NORMAL THROUGHOUT.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
AT 230 PM EDT TUESDAY...ON WEDNESDAY NIGHT A HIGH AMPLITUDE UPPER
RIDGE WILL BE OVER MOST OF THE EAST...WITH AN EMBEDDED UPPER LOW
OVER THE MID ATLANTIC COAST...WHILE A CLOSED UPPER LOW WILL BE
LOCATED OVER THE SOUTHERN PLAINS. THE ATLANTIC UPPER LOW WEAKENS AND
DRIFTS SOUTH THROUGH FRIDAY...WHILE THE CLOSED LOW PROGRESSES
NORTHEAST INTO THE CENTRAL PLAINS...AND THE UPPER RIDGE NARROWS OVER
THE APPALACHIANS.

A SURFACE RIDGE WILL REMAIN CENTERED OVER THE WESTERN ATLANTIC...
RESULTING IN A WEAK SOUTHERLY UPSLOPE FLOW INTO THE SOUTHERN
APPALACHIANS ON FRIDAY. MOISTURE ASSOCIATED WITH THE COASTAL UPPER
LOW WILL LINGER ON THE COAST...AND MAY EXTEND AS FAR WEST AS THE
INTERSTATE 77 CORRIDOR ON THURSDAY. ON FRIDAY THE COASTAL MOISTURE
DEPARTS WITH ITS UPPER SYSTEM...WHILE GULF INFLOW INTO THE SOUTHERN
APPALACHIANS IMPROVES AHEAD OF A COLD FRONT. THIS FRONT REACHES THE
MOUNTAINS LATE IN THE DAY ON FRIDAY.

SLIGHT CHANCE TO CHANCE POPS WILL BE CARRIED ON THURSDAY...GREATEST
DURING DAYTIME HEATING AND NEAR THE SOUTH FACING BLUE RIDGE
ESCARPMENT...WHERE LIMITED INSTABILITY AND UPSLOPE FLOW COINCIDE.
AS WARM MOIST SOUTHERLY FLOW AND INSTABILITY INCREASE ON FRIDAY...
GREATER POPS WILL BE CARRIED...ESPECIALLY IN THE WEST OVER TERRAIN.
MODEL HELICITY VALUES APPEAR RATHER TAME ON FRIDAY. TEMPERATURES
WILL REMAIN WELL ABOVE NORMAL UNDER THE UPPER RIDGE.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 3 AM TUESDAY...BAND OF SHRA/TSRA ASSOCIATED WITH THE COLD
FRONT WILL LIKELY ARRIVE OVER THE SOUTHERN APPALACHIANS BY MID
DAY...PUSHING EAST DURING THE EVENING AND OVERNIGHT HOURS. GFS
FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE BETWEEN 300 TO 800
J/KG...HELICITY AND SWEAT APPEAR FAIRLY LOW DURING THE PASSAGE OF
THE LINE. I WILL INCREASE POPS TO LIKELY ACROSS THE MTNS...SOLID CHC
EAST. HIGH TEMPERATURES MAY RANGE FROM MID 70S ACROSS THE MTNS TO
AROUND 80 EAST. LOWS IN THE 50S.

SATURDAY AND SUNDAY...THE FORECAST CHALLENGE WILL BE THE PLACEMENT
AND TIMING OF THE CLOSED H5 LOW. IT APPEARS THAT QG FORCING WILL
INCREASE ACROSS THE REGION DURING THE DAY LIGHT HOURS ON
SATURDAY...PEAKING EARLY SUNDAY MORNING...THEN MOVING EAST SUNDAY
AFTERNOON. I WILL INCREASE POPS TO LIKELY ALONG AND NORTH OF I-40
LATE SATURDAY AFTERNOON INTO LATE SATURDAY EVENING...WITH SOLID POPS
SOUTH. FORCING AND MODERATE LAPSE RATES SHOULD SUPPORT A EQUAL
MENTION OF SHRA AND TSRA THROUGH EARLY SUNDAY MORNING. THE CLOSED
LOW...FORCING...AND MOISTURE WILL TRACK EAST DURING THE DAY ON
SUNDAY...RESULTING IN A STEADY DECREASE IN SHRA. HIGH TEMPS WILL
RANGE IN THE LOW 70S ACROSS THE MTNS TO U70S EAST...COOLING TO THE
U60S ACROSS THE MTNS TO MID 70S EAST ON SUNDAY.

MONDAY...H5 RIDGE WILL BUILD ACROSS THE SOUTHEAST U.S. THROUGH THE
DAY. CONDITIONS WILL REMAIN DRY AND MOSTLY CLEAR. TEMPERATURES ARE
FORECAST TO RANGE AROUND 10 DEGREES ABOVE NORMAL.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT...ANY CONVECTION THREATENING THE AIRFIELD LATE TODAY WILL
HAVE TO BE DRIVEN BY OUTFLOWS FROM MTN AND FOOTHILL STORMS...AND
CONFIDENCE IS LOW ON THAT REACHING KCLT. WILL USE CB CLOUD TYPE
AFTER 23Z...AND THEN KEEP CB GOING OVERNIGHT AS A WEAK SHORTWAVE
MOVES SWD TOWARD CENTRAL NC. WILL KEEP ANY CIGS VFR...AND ACCEPT
MVFR CONSENSUS ON FOG TOWARD DAYBREAK. THUNDER CHANCES AT KCLT MAY
BE A BIT BETTER JUST PAST THE CURRENT TAF PERIOD AS THE BEST UPPER
SUPPORT MOVES BY. EXPECT LIGHT SE WINDS THROUGHOUT.

ELSEWHERE...THUNDER CHANCES APPEAR THE BEST FROM KAVL TO KHKY LATE
THIS AFTN THROUGH THIS EVENING. CANNOT RULE OUT TSTMS AT THE UPSTATE
SITES...BUT THIS WILL RELY ON WELL TRAVELED OUTFLOWS TO TRIGGER
ANYTHING. MOST LOCATIONS WILL SEE SCT TO BKN VFR CLOUDS AT 5 KFT OR
LESS...WITH MVFR FOG TOWARD DAYBREAK. THE FOG COULD BE WORSE AT
LOCATIONS RECEIVING RAINFALL THIS EVENING. UPSLOPE TRIGGERING AND A
WEAK SHORTWAVE ARRIVING IN NRLY FLOW ALOFT COULD INCREASE SHRA/TSRA
COVERAGE EARLY WED...BUT UNCERTAINTY IS TOO HIGH TO FEATURE ANY
PRECIPITATION ACROSS WRN NC AT PRESENT. OTHERWISE...EXPECT LIGHT SE
FLOW.

OUTLOOK...A WARM AND UNSTABLE AIRMASS WILL REMAIN IN PLACE THE REST
OF THE WEEK UNTIL A COLD FRONT ARRIVES FROM THE WEST LATE FRI INTO
SAT. EXPECT MAINLY DIURNAL TSTM CHANCES...WITH FOG OR STRATUS
POSSIBLE AROUND DAYBREAK EACH MORNING...ESPECIALLY IN LOCATIONS THAT
SEE RAINFALL THE NIGHT BEFORE.

AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...

WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM

&&

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

&&

SYNOPSIS...SBK
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...NED
AVIATION...HG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
503 AM EDT TUE MAR 20 2012

GAZ010-017-018-026-028-NCZ033-048>053-058-059-062>065-068-501>510-
SCZ001>008-010-210915-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-AVERY-MADISON-YANCEY-MITCHELL-
SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-
SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-CLEVELAND-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-ANDERSON-
503 AM EDT TUE MAR 20 2012

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

.DAY ONE...TODAY AND TONIGHT.

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP
ACROSS THE REGION LATE THIS AFTERNOON AND THIS EVENING. THE MAIN
THREAT FROM THUNDERSTORMS WILL BE LOCALLY HEAVY RAIN AND CLOUD TO
GROUND LIGHTNING.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

GAZ029-NCZ035>037-056-057-069>072-082-SCZ009-011>014-019-210915-
ELBERT-ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-LINCOLN-GASTON-
MECKLENBURG-CABARRUS-UNION NC-YORK-ABBEVILLE-LAURENS-UNION SC-
CHESTER-GREENWOOD-
503 AM EDT TUE MAR 20 2012

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

.DAY ONE...TODAY AND TONIGHT.

ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE REGION
LATE THIS AFTERNOON AND THIS EVENING. THE MAIN THREAT FROM
THUNDERSTORMS WILL BE LOCALLY HEAVY RAIN AND CLOUD TO GROUND
LIGHTNING.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1237 PM EDT TUE MAR 20 2012

NCZ033-501-201715-
AVERY-CALDWELL MOUNTAINS-
1237 PM EDT TUE MAR 20 2012

...A STRONG THUNDERSTORM WILL AFFECT AVERY AND NORTHWESTERN CALDWELL
COUNTIES THROUGH 115 PM EDT...

AT 1231 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR LINVILLE...OR 5 MILES EAST OF NEWLAND. THIS
STORM WAS NEARLY STATIONARY.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO LINVILLE...
  EDGEMONT...SUGAR MOUNTAIN...NEWLAND...MINNEAPOLIS...GRANDFATHER
  MOUNTAIN...ELK PARK...CROSSNORE AND BANNER ELK.

SMALL HAIL...WIND GUSTS UP TO 40 MPH AND TORRENTIAL RAIN ARE EXPECTED
WITH THIS STORM.

LAT...LON 3616 8182 3612 8181 3612 8170 3595 8177
      3598 8187 3600 8190 3597 8193 3598 8206
      3621 8198 3621 8197

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
145 PM EDT TUE MAR 20 2012

NCZ033-050-201830-
AVERY-MITCHELL-
145 PM EDT TUE MAR 20 2012

...A STRONG THUNDERSTORM WILL AFFECT EASTERN MITCHELL AND
SOUTHWESTERN AVERY COUNTIES THROUGH 230 PM EDT...

AT 144 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES EAST OF LEDGER...OR 5 MILES NORTH OF
SPRUCE PINE. THIS STORM WAS NEARLY STATIONARY.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO SPRUCE
  PINE...MINNEAPOLIS...LEDGER...INGALLS...CROSSNORE...BANDANA AND
  BAKERSVILLE.

SMALL HAIL...WIND GUSTS UP TO 40 MPH AND TORRENTIAL RAIN ARE EXPECTED
WITH THIS STORM.

LAT...LON 3600 8190 3595 8196 3592 8196 3586 8214
      3593 8215 3595 8219 3601 8219 3602 8223
      3600 8225 3601 8225 3611 8210 3613 8204
      3615 8201

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
200 PM EDT TUE MAR 20 2012

NCZ506-508-201830-
EASTERN MCDOWELL-GREATER RUTHERFORD-
200 PM EDT TUE MAR 20 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN RUTHERFORD AND
SOUTHEASTERN MCDOWELL COUNTIES THROUGH 230 PM EDT...

AT 156 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES SOUTHEAST OF DYSARTSVILLE...OR 14 MILES
NORTHEAST OF RUTHERFORDTON...MOVING SOUTHEAST AT 15 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO SUNSHINE
  AND DYSARTSVILLE.

SMALL HAIL...WIND GUSTS UP TO 40 MPH AND TORRENTIAL RAIN ARE EXPECTED
WITH THIS STORM.

LAT...LON 3558 8182 3558 8180 3559 8180 3559 8178
      3561 8176 3558 8169 3539 8170 3533 8172
      3550 8197 3564 8185

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
221 PM EDT TUE MAR 20 2012

NCZ051-052-059-201900-
HAYWOOD-NORTHERN JACKSON-SWAIN-
221 PM EDT TUE MAR 20 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN SWAIN...
NORTHWESTERN JACKSON AND WESTERN HAYWOOD COUNTIES THROUGH 300 PM
EDT...

AT 217 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 6 MILES EAST OF SMOKEMONT...OR 13 MILES NORTHWEST
OF WAYNESVILLE...MOVING SOUTHWEST AT 5 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO
  SMOKEMONT...MAGGIE VALLEY AND CHEROKEE.

SMALL HAIL...WIND GUSTS UP TO 40 MPH AND TORRENTIAL RAIN ARE EXPECTED
WITH THIS STORM.

LAT...LON 3537 8328 3557 8346 3569 8318 3554 8305

07