Severe Thunderstorm Warning 512, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
250 PM EDT MON AUG 7 2006

.SHORT TERM /TONIGHT THROUGH SUNDAY/...
SCATTERED TSTMS WILL CONTINUE TO PERCOLATE INTO THE EVENING HOURS
ACRS THE CWFA WITHIN MODERATELY UNSTABLE AIRMASS. ATMOSPHERE IS
PRETTY WEAKLY FORCED...AND SOURCES OF LIFT/TRIGGERS WILL RANGE FROM
TERRAIN...LEE/PIEDMONT TROUGH TO POSSIBLE OUTFLOW FROM EARLIER
STORMS OVER SW VA. 12 UTC SNDGS VERY MOIST...PWATS AT KGSO ARE 160
PERCENT OF NORMAL WITH EXPECTEDLY VERY HIGH FREEZING LEVELS.
SO...EXPECT ONGOING ISOLATED WET MICROBURST AND LOCALLY TORRENTIAL
RNFL THREAT. WILL PLAN ON MAX TEMPS ABOUT A DEGREE OR TWO HIGHER ON
TUESDAY AS NAM INDICATES A BOOST IN LLVL THICKNESS VALUES...LEADING
TO HEAT INDEX VALUES AROUND 100 DEG F.  MODEL TIMEHEIGHTS SHOW DEEP
LAYER RH LESS PREVALENT AND ATMOSPHERE CONTINUES TO BE WEAKLY
FORCED. NONETHELESS...WOULD EXPECT ANOTHER AFTERNOON WITH MODERATE
AMOUNTS OF INSTABILITY. FOCUSING MECHANISM...IN THE FORM OF
SOUTHWARD MOVING FRONT LOOKS TO DROP INTO THE NORTHERN EDGE OF THE
CWFA BY LATE AFTERNOON. ALL IN ALL...LITTLE CHANGE FROM GOING
SENSIBLE WX FCST...AFTERNOON SCATTERED TSTMS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH MONDAY/...
SUN NGHT THROUGH THU NGHT...
WEAK BACK DOOR COLD FRONT WILL PUSH INTO THE SOUTHERN PART OF THE
UPSTATE BY WEDNESDAY MORNING. PCPN SHOULD END FAIRLY QUICKLY TUE
EVENING DESPITE THE PROXIMITY OF THE FRONT AS THE STRONGEST LLVL
CONVERGENCE AND THE BEST UPPER LEVEL SUPPORT WILL BE OVER THE
EASTERN CAROLINAS. DURING THE DAY OF WED THE FRONT BECOMES QUITE
DIFFUSE...BUT A WEAK AREA OF SURFACE CONVERGENCE REMAINS OVER THE
UPSTATE AND CENTRAL NC MTNS PER BOTH THE GFS AND NAM. DEEP LAYER
SHEAR IS ONLY ON THE ORDER OF 20 KTS...BUT HIGH PRECIPITABLE WATER
AND K INDICES IN THE UPPER 30S SHOULD SUPPORT QUITE A BIT OF
CONVECTION IN THE AFTERNOON. HAVE GONE WITH HIGH CHANCE POPS MOST
AREAS...WITH THE LOWEST POPS IN THE SLIGHTLY MORE STABLE AIR NORTH
OF I-40 IN THE NC FOOTHILLS AND PIEDMONT. POPS MAY NEED TO BE
BUMPED UP INTO THE LIKELY RANGE ALONG THE SFC BNDRY...BUT WL LEAVE
THAT FOR LATER SHIFTS. DON/T SEE MUCH OF A SEVERE THREAT...BUT
SOME ISOLATED FLASH FLOODING COULD BE A CONCERN WITH THE UPSLOPE
FLOW BALANCED AGAINST THE NORTHWEST FLOW ALOFT.

PCPN WILL SLOWLY TAPER OFF WED EVENING...THOUGH SOME MODEL
DIFFERENCES BEGIN TO CREEP INTO THE PICTURE AT THIS POINT. THE GFS
DEVELOPS AN MCS OVER IN AND NRN KY WED AFTERNOON. IT TRACKS THIS
SYSTEM SOUTHEAST WED NIGHT AND CLIPS OUR NRN ZONES AFTER MIDNIGHT.
THE NAM IS NOT NEARLY AS AGGRESSIVE IN DEVELOPING THIS MCS.
HOWEVER...ABOUT 18 HOURS LATER THE NAM DOES DEVELOP AS MCS IN THIS
SAME AREA...WHICH IT BRINGS INTO THE NC MTNS BY MID MORNING ON THU.
SO...SOMETHING PROBABLY WILL DEVELOP UPSTREAM WED OR WED NIGHT...AND
IT MAY WELL TRACK INTO THE MTNS WED NGHT OR THU. HOWEVER...THE
TIMING DIFFERENCES ARE TOO GREAT TO BE ABLE TO INCREASE POPS
MUCH...OR TO NAIL DOWN A SEVERE THREAT. THEREFORE...WILL GO WITH
MAINLY A DIURNAL POP TREND WED NIGHT AND THU WITH THE LOWEST POPS
OVERNIGHT AND THE HIGHEST POPS THU AFTERNOON...THOUGH THESE WILL BE
FAIRLY LOW...GENERALLY IN THE 30 TO 40 PERCENT RANGE.

FRI THROUGH MON...
HPC HAS GONE WITH A ECMWF...GFS ENSEMBLE BLEND IN THE EXTENDED. ALL
THE MEDIUM RANGE MODELS DEVELOP A STRONG BUT PROGRESSIVE LONG WAVE
TROF OVER THE NE STATES INTO THE WEEKEND. ON THE GFS THIS SENDS A
FRONT THROUGH ALL OF THE FORECAST AREA EARLY IN THE WEEKEND. IT HAS
SOME UPSLOPE PCPN ON SATURDAY...BUT STRONGLY SUGGESTS THAT SUNDAY
AND MONDAY WILL BE COOLER (IN A RELATIVE SENSE) AND DRY. OTHER THAN
HPC HOLDING ON TO PCPN CHANCES ON SUNDAY...THIS IS QUITE SIMILAR TO
THEIR SOLUTION. OF COURSE...HPC GUIDANCE GRIDS WERE USED...SO OUR
FORECAST REFLECTS THE HPC SOLUTION REGARDLESS.

&&

.AVIATION...
CONFIDENCE STILL NOT HIGH ENOUGH YET TO FCST ANY WX MORE PESSIMISTIC
THAN VCSH/CB COMBO AT ALL THE TERMINALS THIS AFTERNOON/EVENING. THE
MAIN CHANGE WAS TO PUSH BACK START OF ANY POTENTIAL DEEP CONVECTION
THREAT AN HOUR OR TWO BASED ON LATEST RADAR AND STATE OF DEVELOPING
CU FIELD. JUST MADE SOME DOWNWARD TWEAKS TO FOG FCST OVERNIGHT BASED
EITHER ON WHAT OCCURRED THIS MORNING AND/OR BASED ON DWPT TRENDS
AND CROSSOVER TEMPS THIS AFTERNOON. INTRODUCED IFR CHANCES AT KAVL
AND MVFR POSSIBILITIES AT KCLT. GOING VFR FOG AT KGSP/KGMU AND MVFR
AT KAND/KHKY STILL LOOK ON TRACK.

&&

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

SHORT TERM...CSH
LONG TERM...MCAVOY
AVIATION...CSH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
312 AM EDT MON AUG 7 2006

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-080715-
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-
312 AM EDT MON AUG 7 2006

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED...MAINLY THIS AFTERNOON AND
EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SCATTERED THUNDERSTORMS ARE EXPECTED EACH DAY...MAINLY DURING THE
AFTERNOON AND EVENING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
434 PM EDT MON AUG 07 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0405 PM     HAIL             2 WNW UNION GROVE       36.04N 80.90W
08/07/2006  E0.75 INCH       IREDELL            NC   FIRE DEPT/RESCUE

&&

GMS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
434 PM EDT MON AUG 7 2006

NCZ064-065-SCZ003-006-072130-
GREATER GREENVILLE-GREENVILLE MOUNTAINS-HENDERSON-TRANSYLVANIA-
434 PM EDT MON AUG 7 2006

...A STRONG THUNDERSTORM WAS AFFECTING GREENVILLE...HENDERSON AND
TRANSYLVANIA COUNTIES...

AT 431 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES NORTH OF CAESARS HEAD...OR 9 MILES
SOUTHEAST OF BREVARD...MOVING SOUTHEAST AT 10 MPH.

THIS STORM WILL BE NEAR...
  CAESARS HEAD BY 450 PM EDT.
  MARIETTA BY 530 PM EDT.

SMALL HAIL AND WINDS TO 40 TO 50 MPH ARE EXPECTED WITH THIS
THUNDERSTORM.

44

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
450 PM EDT MON AUG 07 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0235 PM     TSTM WND DMG     SPENCER                 35.69N 80.43W
08/07/2006                   ROWAN              NC   EMERGENCY MNGR

            2 TREES DOWN ON THIRD ST.

&&

GMS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
503 PM EDT MON AUG 7 2006

NCZ056-069-072200-
CATAWBA-LINCOLN-
503 PM EDT MON AUG 7 2006

...A STRONG THUNDERSTORM WAS AFFECTING CATAWBA COUNTY AND HEADED
TOWARD LINCOLN COUNTY...

AT 503 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 6 MILES NORTHEAST OF VALE...OR 8 MILES SOUTHWEST
OF NEWTON...MOVING SOUTHEAST AT 15 MPH.

THIS STORM WILL BE NEAR...
  MAIDEN BY 520 PM EDT.
  5 MILES NORTHEAST OF LINCOLNTON BY 530 PM EDT.
  BOGER CITY BY 535 PM EDT.
  IRON STATION BY 550 PM EDT.
  5 MILES SOUTHWEST OF DENVER BY 555 PM EDT.
  LOWESVILLE BY 600 PM EDT.

PEA SIZE HAIL...AND WINDS 30 TO 40 MPH ARE EXPECTED WITH THIS STORM.
FREQUENT LIGHTNING AND TORRENTIAL RAIN WILL ALSO ACCOMPANY THIS
THUNDERSTORM.

HG

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
515 PM EDT MON AUG 07 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0322 PM     HAIL             9 NNE WAYNESVILLE       35.60N 82.94W
08/06/2006  E0.88 INCH       HAYWOOD            NC   PUBLIC

            A PUBLIC REPORT OF A BRIEF PERIOD OF NICKEL-SIZED HAIL
            FELL NEAR THE BEGINNING OF THE STORM. GUSTY WIND ROCKED
            THE TREES BUT NOT ENOUGH TO CAUSE ANY TREES TO FALL OR
            ANY LARGE LIMBS. THIS LOCATION IS BETWEEN COVE CREEK AND
            CRABTREE.

&&

MCAVOY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
534 PM EDT MON AUG 7 2006

SCZ009-072215-
YORK-
534 PM EDT MON AUG 7 2006

...A STRONG THUNDERSTORM WAS AFFECTING YORK COUNTY...

AT 534 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR MCCONNELLS...OR 7 MILES SOUTHWEST OF YORK...
MOVING SOUTHEAST AT 10 MPH.

THIS STORM WILL BE NEAR...
  MCCONNELLS BY 550 PM EDT.

PEA SIZE HAIL...AND WINDS 30 TO 40 MPH ARE EXPECTED WITH THIS STORM.

HG