Severe Thunderstorm Warning 509, 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.

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

NCZ036-037-057-072-082-071920-
CABARRUS-DAVIE-IREDELL-ROWAN-UNION-
214 PM EDT MON AUG 7 2006

...STRONG THUNDERSTORMS OVER THE NORTH CAROLINA PIEDMONT...

AT 210 PM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED
STRONG THUNDERSTORMS OVER THE NORTH CAROLINA PIEDMONT.  STRONG
THUNDERSTORMS REDEVELOPED OVER THE SAME LOCATIONS OVER EASTERN
IREDELL COUNTY...NEAR THE CONJUNCTION WITH DAVIE AND ROWAN
COUNTIES.  RADAR ESTIMATES OF 1 TO 2 INCHES OF RAIN HAS FALLEN
IN AN HOURS TIME IN A RURAL AREA OF THE COUNTY.  THESE STORMS
ARE MOVING TO THE EAST SOUTHEAST AT 10 MPH AND WILL AFFECT
NORTHERN ROWAN COUNTY INTO THE MID AFTERNOON.

OTHER STRONG STORMS WERE OVER SOUTHEAST UNION COUNTY AND PARTS
OF CABARRUS COUNTY.  THOSE ARE ALSO MOVING EAST SOUTHEAST AT
10 MPH.

EXPECT STRONG WIND GUSTS WITH THE STRONGEST STORMS AS WELL AS
FREQUENT DEADLY LIGHTNING AND VERY HEAVY RAIN IN A SHORT TIME.

STAY TUNED TO NOAA WEATHER RADIO OR LOCAL NEWS MEDIA FOR THE
LATEST WEATHER INFORMATION.

OUTLAW

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

NCZ082-071930-
UNION-
229 PM EDT MON AUG 7 2006

...A STRONG THUNDERSTORM WAS AFFECTING UNION COUNTY...

AT 229 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 7 MILES SOUTH OF MONROE. THIS STORM WAS MOVING
SLOWLY SOUTHWARD.

THIS STORM WILL CONTINUE MOVING SOUTHWARD AND WILL SLIDE JUST WEST
OF TRINITY BY 245 PM BEFORE EXITING THE COUNTY. HEAVY
DOWNPOURS...WITH HOURLY RAINFALL RATES BETWEEN ONE AND TWO INCHES
WILL BE POSSIBLE.

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

BSH

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

NCZ071-072015-
MECKLENBURG-
324 PM EDT MON AUG 7 2006

...A STRONG THUNDERSTORM WAS AFFECTING CHARLOTTE...

AT 324 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR SOUTHPARK MALL...OR NEAR CENTER CITY
CHARLOTTE...MOVING SOUTHWEST AT 5 MPH.

THIS STORM WILL BE NEAR...
  PINEVILLE BY 425 PM EDT.

PEA SIZE HAIL...WIND GUSTS OF 30 TO 40 MPH...AND TORRENTIAL RAINFALL
ARE EXPECTED WITH THIS STORM.

HG

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

NCZ036-072015-
IREDELL-
327 PM EDT MON AUG 7 2006

...A STRONG THUNDERSTORM WAS AFFECTING IREDELL COUNTY...

AT 327 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR TROUTMAN...OR NEAR STATESVILLE...MOVING
SOUTHEAST AT 20 MPH.

THIS STORM WILL BE NEAR...
  TROUTMAN THROUGH 340 PM EDT.
  MOORESVILLE BY 400 PM EDT.

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

HG

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

NCZ504-072030-
GREATER BURKE-
345 PM EDT MON AUG 7 2006

...A STRONG THUNDERSTORM WAS AFFECTING BURKE COUNTY...

AT 345 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR MORGANTON...MOVING SOUTH AT 10 MPH. THIS
THUNDERSTORM WILL AFFECT LOCATIONS SOUTH OF INTERSTATE 40 IN BURKE
COUNTY THROUGH 430 PM. PEA SIZE HAIL...AND WINDS 30 TO 40 MPH ARE
EXPECTED WITH THIS STORM.

HG

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

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

0335 PM     HAIL             1 N MOUNT PLEASANT      35.42N 80.44W
08/07/2006  E0.75 INCH       CABARRUS           NC   TRAINED SPOTTER

            3/4 INCH HAIL ALONG MT. PLEASANT ROAD...NEAR HIGHWAY
            49...JUST NORTH OF MOUNT PLEASANT.

&&

BSH