Severe Thunderstorm Warning 214, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
236 AM EDT TUE JUN 16 2009

.SYNOPSIS...
A STATIONARY FRONT SOUTH OF THE FORECAST AREA WILL LINGER THROUGH
WEDNESDAY THEN WILL MOVE OFF THE COAST ON THURSDAY. A COLD FRONT
WILL MOVE ACROSS THE CAROLINAS ON SATURDAY. WEAK HIGH PRESSURE WILL
BUILD OVER THE REGION EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
MOST OF THE ANCHORED CONVECTION OVER THE PAST FEW HOURS HAS BEEN
NORTH OF THE FA. PRESENTLY THERE ISN/T A GREAT DEAL OF ACTIVITY
UPSTREAM OF OUR FA. HOWEVER...THE NAM AND GFS STILL IMPLY THAT THE
GOOD H8 LLVL CONVERGENCE WILL DROP A LITTLE FARTHER TO THE SOUTH
THROUGH 12 UTC...AND THAT CONVECTION SHOULD BEGIN TO PICK UP IN
COVERAGE OVER THE NRN PART OF THE FA. PW/S ARE STILL QUITE HIGH IN
THAT AREA...AND THERE IS QUITE A BIT OF CAPE PER LAST NIGHT/S RNK
AND GSO SOUNDINGS MODIFIED FOR CURRENT CONDITIONS. MAINLY WE NEED
JUST A SMALL INCREASE IN THE EASTERLY UPSLOPE FLOW TO HELP KICK
THINGS OFF. IF THIS DOESN/T HAPPEN...THEN WE PROBABLY WON/T SEE MUCH
UP ALONG THE I-40 CORRIDOR AFTERALL. I/LL KEEP THE FLASH FLOOD WATCH
GOING THROUGH 9 AM. I WON/T EXTEND IT IN TIME RIGHT NOW OWING TO THE
LACK OF ACTIVITY OVER THE WATCH AREA. STILL...WITH ADDITIONAL MCV/S
WORKING ACROSS THE REGION TODAY...AND A DEFINITE INCREASE IN UPSLOPE
FLOW...WE MAY NEED TO RUN THE WATCH LATER IN THE DAY.

SPC HAS PUT THE SRN PART OF THE FA IN A SLIGHT RISK FOR LATER IN THE
DAY. WHILE THE NORTH WILL SEE COOLER ENE SFC FLOW...WINDS OVER THE
SW PART OF THE FA SHOULD TURN BACK OUT OF THE SW WITH STRONG SFC
CONVERGENCE SETTING UP OVER THE SW NC MTNS AND WRN UPSTATE. MODEL
SOUNDINGS HAVE BETTER LOOKING CAPE FOR TDA THAN THEY DID FOR
YDAY...AND WITH 35 TO 40 KT KINDS AT H5...CHANCES FOR SEVERE STORMS
LOOK A LITTLE BETTER THAN YDAY IN THE SRN PART OF THE FA.

A NARROW WEDGE OF SFC HIGH PRESSURE WILL WORK IT/S WAY INTO THE REST
OF THE FA TONIGHT. PCPN CHANCES WILL STILL BE GOOD WITH H5 SHORT
WAVES MOVING ACROSS THE REGION...BUT INSTABILITY WILL BE LESS. H8
UPSLOPE FLOW LOOKS TO INCREASE AS SFC LOW PRESSURE PASSES TO OUR
NORTH. THE NAM WIND FIELD IMPLIES THAT MORE ANCHORED CONVECTION
WOULD BE POSSIBLE ACROSS THE NC MTNS AND FOOTHILLS OVERNIGHT. THE
GFS HAS ITS BEST LLVL UPSLOPE FLOW UP IN BLACKSBURG/S AREA.
CONFIDENCE IS NOT HIGH...BUT WE WILL STILL NEED TO WATCH FOR A
POSSIBLE ISOLATED FLASH FLOOD THREAT UP IN THAT AREA AGAIN TONIGHT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 220 AM EDT TUE...THE NAM AND GFS AGREE ON AN UPPER RIDGE OVER
THE WESTERN GULF STATES WED MORNING...BUT DISAGREE ON THE POSITION
OF AN UPPER LOW OVER THE GREAT LAKES. THE GFS HAS HAD DECENT
CONTINUITY WITH THIS FEATURE...BUT THE ECMWF LOOKS MORE NAM LIKE IN
THIS REGARD. THE MAIN IMPLICATION FROM THIS DIFFERENCE IS THAT THE
GFS HAS MORE AMPLITUDE TO AN EAST COAST TROUGH...AND TRIES TO DRIVE
A WEAK COLD FRONT ACROSS OUR AREA ON THU...SCOURING OUT A MOIST
SURFACE RIDGE EAST OF THE MOUNTAINS. MAJOR DIFFERENCES ARE ALSO
NOTED IN GUIDANCE TEMPERATURE FORECASTS...ESPECIALLY DAYTIME
MAXIMUMS...WHICH ARE SIGNIFICANTLY WARMER IN THE GFS. THE NAM IS
SUFFICIENTLY VAGUE WITH ITS SURFACE PATTERN AND MOISTURE AT 60 HOURS
TO RAISE DOUBTS ABOUT ITS SOLUTION AS WELL. WITH CONFIDENCE LOW...
PREFER A BLEND OF THE TWO THAT MIMICS FORECAST CONTINUITY...AND
TRENDS TOWARD THE HPC DAY 4 MEDIUM RANGE SOLUTION. THAT WOULD ALLOW
FOR SOME KIND OF WAVE DEVELOPMENT ON THE EXISTING FRONT THAT LESSENS
UPSLOPE FLOW...WHILE THE FRONT IN THE OH VALLEY REMAINS TO OUR
NORTH. BOTH MODELS HINT AT THIS WAVE DEVELOPMENT...THOUGH NOT AS
MUCH AS IN PREVIOUS RUNS.

CHANCE POPS FOR CONVECTION WILL BE CARRIED AREA WIDE ON WEDNESDAY...
TRENDING TOWARD SLIGHT CHANCE IN THE LEE OF THE MOUNTAINS ON
THURSDAY. TEMPERATURES WILL ALSO REFLECT A COMPROMISE...WITH CLOUDS
KEEPING MAXIMUMS AROUND 5 DEGREES BELOW NORMAL WED...AND DECREASING
CLOUDS ALLOWING TEMPERATURES TO RISE ABOVE NORMAL ON THU.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 220 AM EDT TUE...THE ECMWF AND GFS START FRIDAY OUT WITH A
RIDGE FROM THE GULF STATES TO THE GREAT LAKES. AN UPPER LOW CROSSING
THE GREAT LAKES FLATTENS THIS RIDGE ON SATURDAY...THEN FORMS AN EAST
COAST TROUGH BY SUNDAY...BU WHICH TIME THE GFS OPENS UP THE LOW AND
BECOMES FASTER WITH THE REMAINING TROUGH. THIS TREND CONTINUES INTO
MONDAY. HPC EXPRESSED A PREFERENCE FOR A BLENDED SOLUTION.

ON FRIDAY BOTH THE GFS AND HPC SOLUTION HAVE A FRONT TO OUR
NORTH...WITH OUR AREA IN THE WARM SECTOR. A COLD FRONT APPROACHES
FROM THE NORTHWEST ON SATURDAY...REACHING THE CAROLINA COAST BY
SUNDAY. ON MONDAY BOTH SOLUTIONS HAVE THIS FRONT STATIONARY AND
WELL TO OUR SOUTH. POPS WILL BE QUITE LIMITED UNTIL THE FRONT
APPROACHES SATURDAY. FOLLOWING THE FRONT...ISOLATED DIURNAL
CONVECTION IS EXPECTED. TEMPERATURES WILL BE WELL ABOVE NORMAL
BEFORE THE FRONTAL PASSAGE...COLLING TO JUST SLIGHTLY ABOVE NORMAL
BEHIND THE FRONT.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
KCLT AND ELSEWHERE...LIGHT EASTERLY WINDS WILL HELP TO GRADUALLY
LOWER CIGS AT THE NC TAF SITES THIS MORNING. HOWEVER...THE LIGHT
FLOW WILL MAKE IT HARD TO HOLD IN CIGS AT ANY ONE LEVEL...AND THERE
IS LIKELY TO BE A LOT OF BOUNCING AROUND BETWEEN CATEGORIES.
EVENTUALLY KCLT AND HKY WILL SETTLE INTO THE IFR RANGE WITH AN
INCREASING NUMBER OF SHRA IN THE VICINITY. A WEAK TROUGH IS OVER
WESTERN NORTH CAROLINA...WITH ESE WINDS AT KCLT AND ENE AT KHKY.
THIS SHOULD CONTINUE UNTIL SUNRISE WHEN THE WINDS SHOULD GO NE AT
KCLT AS WELL.

CIGS WILL NOT LOWER AS QUICKLY OVER THE UPSTATE. THERE IS SOME
CONSTRUCTION GOING ON NEAR THE KGSP ASOS WHICH IS CURRENTLY CAUSING
THE VERY LOW CIGS. THE TOWER IS CLOSED...SO THERE IS NO WAY TO EDIT
THE DATA. KAVL REALLY WILL SEE DENSE VALLEY FOG AT TIMES...BUT HIGH
CIGS MAY KEEP IT FROM HOLDING IN. WINDS WILL BE OUT OF THE NE AT
MOST SITES...THOUGH KAND IS LIKELY TO HAVE A WSW WIND MUCH OF THE
LATE MORNING AND AFTERNOON HOURS.

OUTLOOK...CIG/VSBY RESTRICTIONS POSSIBLE IN SHWRS/TSTMS
TUE/WED...ALONG WITH AREAS OF LOW CLOUDS AND FOG IN THE MORNING.
CHANCES OF RESTRICTIONS WILL DECREASE CONSIDERABLY THU-FRI AS DRIER
HIGH PRESSURE BUILDS INTO THE REGION FOR A COUPLE DAYS.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...FLASH FLOOD WATCH UNTIL 9 AM EDT THIS MORNING FOR NCZ033-
     035>037-049-050-056-057-501>506.
SC...NONE.

&&

SYNOPSIS...JAT
NEAR TERM...MCAVOY
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...MCAVOY

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
529 AM EDT TUE JUN 16 2009

GAZ010-017-018-026-028-029-NCZ048-051>053-058-059-062>065-068>072-
082-507>510-SCZ001>014-019-171000-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-MADISON-SWAIN-HAYWOOD-
BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
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-
529 AM EDT TUE JUN 16 2009

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

.DAY ONE...TODAY AND TONIGHT.

THUNDERSTORMS ARE IN THE FORECAST TODAY AND TONIGHT. SOME OF THESE
THUNDERSTORMS COULD BECOME SEVERE...PRODUCING LARGE HAIL AND
DAMAGING WINDS. HEAVY RAINFALL IS POSSIBLE.

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

THUNDERSTORMS ARE IN THE FORECAST WEDNESDAY AND WEDNESDAY NIGHT. A
FEW OF THESE THUNDERSTORMS COULD BECOME SEVERE...PRODUCING LARGE
HAIL AND DAMAGING WINDS.

HEAT INDEX VALUES OF 105 DEGREES ARE POSSIBLE FRIDAY AND SATURDAY
IN THE UPPER SAVANNAH RIVER VALLEY OF NORTHEAST GEORGIA AND
UPSTATE SOUTH CAROLINA.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF LARGE
HAIL...DAMAGING WINDS...TORNADOES OR FLASH FLOODING TO OUR OFFICE.

NCZ033-035>037-049-050-056-057-501>506-171000-
AVERY-ALEXANDER-IREDELL-DAVIE-YANCEY-MITCHELL-CATAWBA-ROWAN-
CALDWELL MOUNTAINS-GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-
MCDOWELL MOUNTAINS-EASTERN MCDOWELL-
529 AM EDT TUE JUN 16 2009

...FLASH FLOOD WATCH IN EFFECT UNTIL 9 AM EDT THIS MORNING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PIEDMONT NORTH CAROLINA AND
WESTERN NORTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   FLASH FLOOD WATCH.

THUNDERSTORMS ARE IN THE FORECAST TODAY AND TONIGHT. SOME OF THESE
THUNDERSTORMS COULD BECOME SEVERE...PRODUCING LARGE HAIL AND
DAMAGING WINDS. HEAVY RAINFALL IS POSSIBLE.

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

THUNDERSTORMS ARE IN THE FORECAST WEDNESDAY AND WEDNESDAY NIGHT. A
FEW OF THESE THUNDERSTORMS COULD BECOME SEVERE...PRODUCING LARGE
HAIL AND DAMAGING WINDS.

HEAT INDEX VALUES OF 105 DEGREES ARE POSSIBLE FRIDAY AND SATURDAY
IN THE UPPER SAVANNAH RIVER VALLEY OF NORTHEAST GEORGIA AND
UPSTATE SOUTH CAROLINA.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF LARGE
HAIL...DAMAGING WINDS...TORNADOES OR FLASH FLOODING TO OUR OFFICE.

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1226 AM EDT TUE JUN 16 2009

NCZ057-160530-
ROWAN-
1226 AM EDT TUE JUN 16 2009

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL ROWAN COUNTY THROUGH 130
AM EDT...

AT 1225 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES EAST OF CLEVELAND...OR 7 MILES WEST OF
SALISBURY...MOVING SOUTHEAST AT 10 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO SPENCER...
  SALISBURY...ROCKWELL...GRANITE QUARRY...FAITH AND CRAVEN.

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THIS STORM.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK
HIGHER GROUND IF THREATENED BY FLOOD WATERS.

MCAVOY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
507 AM EDT TUE JUN 16 2009

NCZ036-161000-
IREDELL-
507 AM EDT TUE JUN 16 2009

...A THUNDERSTORM WITH HEAVY RAIN WILL AFFECT NORTHERN IREDELL
COUNTY THROUGH 600 AM EDT...

AT 506 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 9 MILES WEST OF HARMONY...OR 12 MILES NORTH OF
STATESVILLE...MOVING SOUTHEAST AT 10 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO TURNERSBURG
  AND HARMONY.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK
HIGHER GROUND IF THREATENED BY FLOOD WATERS.

MCAVOY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
535 AM EDT TUE JUN 16 2009

NCZ036-037-057-161030-
DAVIE-IREDELL-ROWAN-
535 AM EDT TUE JUN 16 2009

...A STRONG THUNDERSTORM WILL AFFECT EASTERN IREDELL...NORTHWESTERN
ROWAN AND WESTERN DAVIE COUNTIES THROUGH 630 AM EDT...

AT 533 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES SOUTHWEST OF HARMONY...OR 8 MILES NORTH
OF STATESVILLE...MOVING SOUTHEAST AT 15 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO TURNERSBURG
  AND CLEVELAND.

SMALL HAIL...WIND GUSTS OF 30 TO 40 MPH AND RAINFALL RATES OF 1 TO 2
INCHES PER HOUR ARE EXPECTED WITH THIS STORM.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER
LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK
HIGHER GROUND IF THREATENED BY FLOOD WATERS.

MCAVOY