Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
223 PM EDT MON JUL 16 2012

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL CONTINUE TO CONTROL OUR WEATHER THROUGH
MID-WEEK. A FRONTAL BOUNDARY OVER THE OHIO VALLEY IS EXPECTED TO
DROP SOUTH ACROSS THE REGION BY LATE THURSDAY AND LINGERS INTO
SATURDAY. THEN HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE
NORTH BY SUNDAY AND REMAIN THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
AT 230 PM EDT MONDAY...AN UPPER LOW WILL REMAIN OVER EASTERN CANADA
TONIGHT AND TUESDAY....BUT THE MEAN TROUGH TO ITS SOUTH WILL LOSE
AMPLITUDE. MEANWHILE...A WEAK UPPER LOW OFF THE COAST OF NE FL WILL
MOVE WEST AND INLAND. CONVECTION IS EXPECTED TO DEVELOP THIS
AFTERNOON AS AN UPPER IMPULSE DIVES INTO THE EAST COAST TROUGH...
LINGERING INTO THE EARLY EVENING. THE RETROGRADING FL SYSTEM MAY
HAVE SUFFICIENT REACH BY TUESDAY TO STEER UPPER IMPULSES WEST ACROSS
GA AND THE CAROLINAS INTO THE BLUE RIDGE...PERHAPS CAUSING
PRECIPITATION TO DEVELOP EARLY TUESDAY MORNING. MINIMUM TEMPERATURES
TONIGHT WILL BE NEAR NORMAL...AND MAXIMUM TEMPERATURES TUESDAY WILL
BE SLIGHTLY ABOVE NORMAL.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AT 145 PM EDT...WEAK TROUGHING ALOFT WILL CONTINUE TO DEVELOP OVER
THE SE STATES IN THE SHORT TERM AS A STRONG SHORT WAVE MOVES INTO
NORTHERN NEW ENGLAND AND A WEAK UPPER LOW OVER FLORIDA MEANDERS
GENERALLY WESTWARD. AT THE SURFACE...WEAK HIGH PRESSURE WILL REMAIN
CENTERED OVER THE SOUTHERN APPALACHIANS WITH LEE TROUGHING EAST OF
THE MOUNTAINS. WITH A MOIST BOUNDARY LAYER IN PLACE...PLAN VIEW
CAPES ARE FORECAST TO EXCEED 2000J/KG OVER MANY PIEDMONT AREAS BOTH
WED AND THU AFTERNOONS WITH WELL OVER 1000J/KG ELESWHERE. THIS SET
UP FAVORS RATHER TYPICAL JULY WEATHER WITH DIURNALLY ENHANCED
THUNDERSTORMS ERUPTING DURING THE AFTERNOONS AND THEN MOSTLY
DISSIPATING DURING THE EVENING HOURS. BUFKIT SOUNDINGS SUPPORT THIS
IDEA AS CONSIDERABLE LOW LEVEL CIN IS INDICATED DURING THE
OVERNIGHT. COVERAGE OF STORMS SHOULD BE BETTER THU AFTERNOON AS A
COLD FRONT SAGS SOUTHWARD TOWARD THE AREA AND UPPER HEIGHTS SLOWLY
FALL. WILL FOLLOW THE POP TREND OF THE PREVIOUS FORECAST.
HOWEVER...DOWNSCALED NAM POPS LOOK REASONABLE SO BLENDED THEM INTO
THE PREVIOUS FORECAST TO GIVE A LITTLE MORE DETAIL. SEVERE THREAT
WITH THUNDERSTORMS IS STILL EXPECTED TO BE ON THE LOW SIDE AS
PROFILES REMAIN RATHER MOIST AND WIND FIELDS WEAK. ISOLD HYDRO
PROBLEMS CAN'T BE RULED OUT DUE TO WEAK STREERING FLOW. TEMP
VERIFICATION DATA OF LATE INDICATES THAT THE BIAS CORRECTED GMOS AND
ADJMAV ARE PERFORMING THE BEST...SO USED A BLEND OF THOSE GUIDANCE
SOURCES FOR TEMPS. THIS YIELDS MAX TEMPS ABOUT A CATEGORY ABOVE AVE
BOTH WED AND THU. MIN TEMPS ALSO ARE FORECAST TO BE A LITTLE ABOVE
AVERAGE.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM SUNDAY...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT THE FRONTAL BOUNDARY OVER THE OHIO VALLEY WILL DROP
SOUTH ACROSS THE APPALACHIANS BY LATE THURSDAY....AND SLOWLY SLIPS
SOUTH INTO THE NC/SC LINE BY FRIDAY AFTERNOON. FORECAST SOUNDINGS
SHOW MODERATE INSTABILITY AND VERY DEEP MOIST LAYER WITH PW VALUES
OVER 2 INCHES DURING THE PASSAGE OF THE FRONTAL BOUNDARY. IN
ADDITION...UPPER LEVEL DIVERGENCE AND DYNAMIC LIFTING WILL PROVIDE
WIDESPREAD CONVECTION ON LATE FRIDAY AS OUR CWA WILL BE UNDER THE
RIGHT ENTRANCE REGION OF THE JET STREAK. HENCE...POPS HAVE BEEN
ACCORDINGLY RAISED INTO THE 60S OVER MUCH OF OUR AREA FRI AFTERNOON
INTO EVENING.

THE FRONT CONTINUES TO SLOWLY DROP FURTHER SOUTH ACROSS THE LOWER
MIDLANDS SAT AND BECOMES STATIONARY THROUGH EARLY PART OF NEXT WEEK.
SO WE WILL SEE DECREASE IN COVERAGE OF CONVECTION AND POPS HAVE BEEN
LOWERED ACCORDINGLY. TEMPERATURES WILL BE 5-10 DEGREES BELOW
SEASONAL AVERAGES WITH HIGHS IN THE LOW TO MID 80S ACROSS THE
PIEDMONT THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT...CONVECTION IN NW NC IS AIMING AT THE INTERSTATE 77
CORRIDOR. ON ITS CURRENT TRAJECTORY...IT PASS TO THE EAST OF
KCLT...SO FOR NO JUST DRY THUNDER WILL BE CARRIED WITH NO
RESTRICTION. MODEL TIME HEIGHTS SUPPORT A LOW VFR CIG THIS AFTERNOON
INTO TONIGHT. GUIDANCE IS BECOMING SUPPORTIVE OF MVFR FOG AT
DAYBREAK...BUT UNTIL CONFIDENCE INCREASES ON FOG...NONE WILL BE
CARRIED. IT IS POSSIBLE THAT PRECIPITATION COULD GET GOING EARLY
TUESDAY...AS AN UPPER LOW DIRECTS IMPULSES ACROSS WESTERN NC FROM
THE EAST. WITH LOW CONFIDENCE...A DRY FORECAST WILL BE FEATURED AT
THIS TIME. LIGHT WINDS SHOULD REMAIN OUT OF THE WSW UNTIL
DAYBREAK...THEN WILL VEER TO WNW.

ELSEWHERE...CONVECTION MOVING IN FROM THE NW SHOULD PASS CLOSE
ENOUGH TO KHKY TO AT LEAST CARRY TS AND CB THIS AFTERNOON....BUT
THIS ACTIVITY WILL PASS WELL EAST OF THE OTHER SITES. ADDITIONAL
THUNDERSTORMS ARE EXPECTED TO FIRE ALONG THE BLUE RIDGE...BUT
CONFIDENCE IS LIMITED THAT THEY WILL CAUSE RESTRICTIONS AT TAF
SITES...SO FOR NOW THUNDER WITH LOW VFR CB WILL BE CARRIED.
GUIDANCE IS BECOMING SUPPORTIVE OF FOG TOWARD DAWN...BUT CONDITIONS
WERE GENERALLY GOOD THIS MORNING...AND ONLY THE MOST LIKELY SPOT...
KAVL...WILL HAVE MVFR FOG IN THE TAF. ANOTHER ROUND OF CONVECTION
COULD DEVELOP EARLY TUESDAY AS AN UPPER LOW DIRECTS IMPULSES WEST
INTO THE BLUE RIDGE...BUT CONFIDENCE IS TOO LOW TO ACCEPT THIS
SCENARIO JUST YET. WINDS ARE EXPECTED TO VEER TO THE NW THIS
AFTERNOON AND REMAIN THERE THROUGH TUESDAY MORNING...EXCEPT AT KAND
WHERE GUIDANCE SUGGESTS LIGHT ENE WINDS AFTER DAYBREAK.

OUTLOOK...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
CONTINUE OVER THE WESTERN CAROLINAS THROUGH WEDNESDAY. THE GREATEST
CHANCE WILL REMAIN OVER THE MOUNTAINS. A COLD FRONT WILL PUSH ACROSS
THE REGION ON THURSDAY AND IS EXPECTED TO REMAIN INTO THE WEEKEND.
THE FRONT WILL BRING AN INCREASED CHANCE FOR THUNDER...CLOUD
COVER...AND FOG OVER SATURATED SOIL.

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...JOH
NEAR TERM...JAT
SHORT TERM...LG
LONG TERM...JOH
AVIATION...JAT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
426 AM EDT MON JUL 16 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-170830-
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 NC-
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-UNION SC-CHESTER-GREENWOOD-
426 AM EDT MON JUL 16 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 AGAIN TODAY...ESPECIALLY OVER THE MOUNTAINS.
THESE SHOWERS WILL BE SLOW MOVING. THIS WILL LEAD TO HEAVY
RAINFALL IN AFFECTED LOCATIONS...WITH ISOLATED FLOODING POSSIBLE.
IN ADDITION...CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE WITH ANY
THUNDERSTORM.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

14

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1255 PM EDT MON JUL 16 2012

SCZ013-014-161745-
CHESTER-UNION-
1255 PM EDT MON JUL 16 2012

...SCATTERED THUNDERSTORMS WILL AFFECT SOUTHERN UNION AND
WESTERN CHESTER COUNTIES THROUGH 145 PM EDT...

AT 1248 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR CARLISLE...OR 11 MILES SOUTHEAST OF UNION.
THIS STORM WAS NEARLY STATIONARY.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO SANTUC...
  UNION...SEDALIA...MONARCH MILLS...LEEDS...CARLISLE AND BUFFALO.

SMALL HAIL IS EXPECTED WITH THIS STORM.

FREQUENT LIGHTNING IS EXPECTED WITH THESE STORMS. IF OUTDOORS...TRY TO
GET INDOORS OR INTO A HARD TOPPED VEHICLE. OTHERWISE...STAY AWAY FROM
OPEN AREAS AND ISOLATED HIGH OBJECTS SUCH AS TREES. WHEN INDOORS...
STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING WIRED ELECTRONIC
DEVICES. TRY TO UNPLUG UNNECESSARY APPLIANCES BEFORE THE STORM
APPROACHES.

LAT...LON 3458 8179 3477 8172 3479 8126 3456 8127
      3456 8141 3456 8142 3450 8141 3450 8142

LG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
230 PM EDT MON JUL 16 2012

NCZ033-050-161915-
AVERY-MITCHELL-
230 PM EDT MON JUL 16 2012

...A STRONG THUNDERSTORM WILL AFFECT MITCHELL AND WESTERN AVERY
COUNTIES THROUGH 315 PM EDT...

AT 225 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES EAST OF LIMESTONE COVE...OR 11 MILES
SOUTH OF ELIZABETHTON...MOVING SOUTHEAST AT 10 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO NEWLAND...
  MINNEAPOLIS...LEDGER...INGALLS...ELK PARK...CROSSNORE...BULADEAN...
  BANDANA AND BAKERSVILLE.

SMALL HAIL...WIND GUSTS OF 40 TO 50 MPH AND TORRENTIAL RAIN ARE
EXPECTED WITH THIS STORM.

FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...TRY TO
GET INDOORS OR INTO A HARD TOPPED VEHICLE. OTHERWISE...STAY AWAY FROM
OPEN AREAS AND ISOLATED HIGH OBJECTS SUCH AS TREES. WHEN INDOORS...
STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING WIRED ELECTRONIC
DEVICES. TRY TO UNPLUG UNNECESSARY APPLIANCES BEFORE THE STORM
APPROACHES.

LAT...LON 3605 8185 3590 8214 3593 8215 3595 8219
      3601 8219 3602 8223 3613 8228 3617 8220
      3615 8218 3615 8215 3611 8212 3611 8208
      3613 8204 3618 8199

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
249 PM EDT MON JUL 16 2012

NCZ035-056-502-504-161930-
ALEXANDER-CATAWBA-GREATER BURKE-GREATER CALDWELL-
249 PM EDT MON JUL 16 2012

...A STRONG THUNDERSTORM WILL AFFECT EASTERN BURKE...NORTHERN
CATAWBA...SOUTHEASTERN CALDWELL AND SOUTHWESTERN ALEXANDER COUNTIES
THROUGH 330 PM EDT...

AT 246 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTH OF KINGS CREEK...OR 7 MILES EAST OF
LENOIR...MOVING SOUTH AT 10 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  HUDSON...
  GRANITE FALLS...

PEA SIZE HAIL...AND WIND GUSTS UP TO 40 MPH...AND HEAVY RAIN ARE
EXPECTED WITH THIS STORM.

LAT...LON 3604 8136 3602 8134 3576 8118 3568 8147
      3599 8156 3604 8137

RB