Hail in North Carolina, September 28, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
210 PM EDT FRI SEP 28 2012

.SYNOPSIS...
HIGH PRESSURE ATOP THE REGION WILL GIVE WAY TO AN APPROACHING COLD
FRONT OVERNIGHT. THE FRONT WILL STALL OUT OVER THE CAROLINAS
BRINGING UNSETTLED WEATHER TO THE REGION AS A LOW RIDES UP ALONG THE
FRONT SATURDAY INTO THE FIRST PART OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM...FOR THE 1730 UTC UPDATE...CONVECTION IS KICKING OFF
ON CUE ACRS THE NRN TIER OF ZONES. SO ONLY MINOR TWEAKS TO THE AFTN
GRIDS WERE MADE. CIRRUS THIN ENUF TO ALLOW GOOD INSOLATION AND
DESTABILIZATION TO 1500 J/KG PER SPC MESOANALYSIS ALONG THE NRN BLUE
RIDGE. EFFECTIVE SHEAR IS ABOUT 25-30 KTS. SO A FEW STRONG TO
MARGINALLY SEVERE STORMS ARE POSSIBLE ACRS THE NRN FOOTHILLS AND NW
PIEDMONT. MORE ISOLD COVERAGE EXPECTED TO THE SOUTH LATER THIS AFTN
INTO EARLY EVENING.

AS OF 1045 AM...FOR THE 1430 UTC UPDATE...OVERALL TRENDS LOOK GOOD
PER SAT/OBS AND LATEST GUIDANCE. ONLY MINOR TWEAKS TO SKY/POPS FOR
THIS AFTN. STILL EXPECTING INCREASING COVERAGE OF SHWRS AND A FEW
TSTMS ACRS MAINLY THE NC ZONES TODAY. SOME LIKELY POPS WERE
INTRODUCED ALONG NRN TIER OF COUNTIES. A MODIFIED 12Z GSO SNDG
PRODUCES OVER 1000 J/KG OF SBCAPE THIS AFTN. SHEAR WAS WEAK AT
12Z...BUT THE NAM AND GFS SHOW SOME INCREASE OF 0-6KM BULK SHEAR
INTO THE 25-35 KT RANGE BY 00Z. MOST OF THE HIGH RES MODELS ARE IN
AGREEMENT ON FAIRLY DISORGANIZED CONVECTION ACRS THE NC MTNS AND NW
PIEDMONT...BUT POSSIBLY SEMI-ORGANIZING INTO LINE SEGMENTS ONCE THEY
TRACK EAST OF THE AREA LATE AFTN/EARLY EVENING. A 5% AREA FOR WIND
INCLUDES OUR NC FOOTHILLS/PIEDMONT FOR SMALL POSSIBILITY OF DAMAGING
WIND GUSTS. WORDING IN HWO LOOKS GOOD.

PREVIOUS DISCUSSION...
WATER VAPOR IMAGERY EARLY THIS MORNING SHOWS EVIDENCE OF A SHORT
WAVE OVER MO...WHICH THE NAM/GFS PICK UP AND MOVE EASTWARD IN THE
QUASI-ZONAL FLOW ALOFT TODAY. THIS FEATURE MOVES ACROSS THE FCST
AREA IN THE LATE AFTERNOON AND EARLY EVENING WITH SOME DPVA AND WARM
ADVECTION...WHICH SHOULD PROVIDE SOME HELP TO THE CONVECTIVE
ENVIRONMENT. MEANWHILE...THE FRONTAL ZONE THAT HAS BEEN STRETCHED
OUT TO THE NORTH WILL DRIFT INTO THE REGION WITH BETTER MOISTURE AND
LOW LEVEL CONVERGENCE. THE NET RESULT SHOULD BE AT LEAST SCATTERED
SHOWERS AND STORMS DEVELOPING FROM N TO S FROM MID MORNING ONWARD.
AREAS N OF I-40 HAVE THE BEST SHOT AND WE MAY ULTIMATELY NEED A
HIGHER POP THERE...BUT FOR NOW A LACK OF CONFIDENCE IN THE GUIDANCE
HAS KEPT THIS TO A CHANCE. THE SRN-MOST ZONES HAVE THE LEAST AMOUNT
OF FORCING SO THE POP WAS KEPT IN THE SLIGHT CHANCE RANGE. FCST
SOUNDINGS ARE NOT ESPECIALLY CONDUCIVE TO STRONG STORMS AS WARMER
MID LEVEL TEMPS WILL LIMIT BUOYANCY. HIGH TEMPS SHOULD BE SIMILAR TO
THURSDAY. THE PASSAGE OF THE SHORT WAVE SHOULD DRAG THE FRONTAL ZONE
DOWN ACROSS THE WESTERN CAROLINAS TONIGHT...AND THUS SHOWERS AND
STORMS WILL BE POSSIBLE AT ANY TIME SIMILAR TO WHAT IS SEEN TO THE
NORTH EARLY THIS AM. WILL STILL LIMIT PRECIP TO THE CHANCE RANGE.
EXPECT MILDER OVERNIGHT TEMPS WITH INCREASED CLOUD COVER.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 135 PM FRIDAY...A RATHER LOW CONFIDENCE FORECAST EVOLVES
DURING THE SHORT TERM IN DEVELOPING SPLIT FLOW REGIME...AND IN LIGHT
OF LIKELY UPPER LOW DEVELOPMENT IN THE SOUTHERN STREAM. SATURDAY
NIGHT...THE MODELS ARE CONVERGING TOWARD A CONSENSUS OF DRIVING THE
FRONTAL ZONE/DRIER AIR THROUGH THE AREA BY 06Z SUNDAY. AS SUCH...WE
WILL BEGIN DIALING DOWN POPS SUCH THAT THEY WILL BE NO GREATER THAN
SLIGHT CHANCE BY 00Z...AND LESS THAN 20 PERCENT BY 12Z. MODEL
SOLUTIONS THEN BEGIN TO DIVERGE QUITE SUBSTANTIALLY ON SUNDAY. IT IS
CERTAIN THAT WARM CONVEYOR BELT MOISTURE/PRECIP WILL OVERSPREAD THE
REGION EARLY NEXT WEEK...AS AFOREMENTIONED UPPER LOW OPENS UP AND
PROGRESSES EAST. HOWEVER...WHILE THE GFS SUGGESTS THIS EVENT WILL
BEGIN SUNDAY MORNING...THE ECMWF HOLDS OFF PRECIP UNTIL 24 HOURS
LATER. TIMING IN OTHER MODEL SOLUTIONS DEPICTS JUST ABOUT EVERYTHING
IN BETWEEN THESE TWO EXTREMES. THERE IS ALSO TREMENDOUS SPREAD IN
THE ENSEMBLE GUIDANCE. WITH THIS IN MIND...HAVE OPTED FOR A
CONSERVATIVE ROUTE AT THIS POINT...BRINGING A LOW CHANCE POP INTO
OUR WESTERN ZONES BY SUNDAY AFTERNOON...GRADUALLY RAMPING UP TO
SOLID CHANCE ACROSS THE SOUTHERN HALF OF THE AREA BY THE END OF
SUNDAY NIGHT...WITH HIGH CHANCE/LIKELY POPS IN ALL AREAS MONDAY.

ONCE PRECIP BEGINS...THE PRESENCE OF BROAD SURFACE HIGH PRESSURE
OVER THE MID-ATLANTIC SUGGESTS IN-SITU COLD AIR DAMMING WOULD LIKELY
DEVELOP. SINCE WE ARE REASONABLY CONFIDENT THAT PRECIP WILL DEVELOP
BY MONDAY...MAX TEMPS AS MUCH AS 10 DEGREES BELOW CLIMO WILL BE
ADVERTISED.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AT 200 PM EDT FRIDAY...BROAD UPPER TROUGH WILL EXIST ACROSS CANADA
FROM TUESDAY THROUGH FRIDAY...WHILE A SOUTHERN STREAM TROUGH WEAKENS
OVER THE OH...TN AND LOWER MS RIVER VALLEYS. A SURFACE WAVE WILL
MOVE FROM FROM THE GULF STATES MONDAY NIGHT TO THE SOUTHERN
APPALACHIANS BY TUESDAY MORNING. UPGLIDE OVER A WARM FRONT TO THE
EAST...AND UPSLOPE FLOW INTO THE BLUE RIDGE ESCARPMENT...WILL SERVE
TO FOCUS SUBSTANTIAL RAINFALL ACROSS OUR AREA. THE WAVE AND ITS
TRAILING COLD FRONT WILL MOVE EAST OF THE AREA BY WEDNESDAY
MORNING...HOWEVER SLOW MOVEMENT OF THE WAVE AND WRAP AROUND MOISTURE
WARRANT SMALL POPS INTO THURSDAY...EVEN AS HIGH PRESSURE BUILDS IN
FROM THE WEST. A COLD FRONT WILL CROSS OUR AREA FROM THE NW ON
FRIDAY...BUT CONFIDENCE IS LOW THAT THIS SYSTEM WILL HAVE MUCH
MOISTURE TO WORK WITH...AND ONLY MINIMAL POPS WILL BE CARRIED WITH
THIS SYSTEM. THE DIURNAL TEMPERATURE RANGE WILL BE LIMITED BY CLOUDS
AND MOISTURE INITIALLY...FOLLOWED BY COOLING.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...BKN TO OVC CIRRUS THIS AFTN WITH A LIGHT VARIABLE
WIND...GENERALLY FAVORING WSW UNTIL SUNSET THEN WNW. CONVECTION IS
EXPECTED TO CONTINUE DEVELOPING ACRS THE NC MTNS AND NW PIEDMONT
THRU THE AFTN INTO EARLY EVENING...GENERALLY ISOLD TO SCATTERED IN
COVERAGE. GUIDANCE KEEPS MOST OF THIS ACTIVITY NORTH OF THE
TERMINAL...BUT A FEW CELLS MAY GET CLOSE. HAVE VCSH WITH A TEMPO FOR
TS FOR THE 21-24Z TIME FRAME. CONVECTION MAY LINGER INTO THE
OVERNIGHT...AS A FTNL BNDRY SAGS SOUTH INTO THE AREA. FOR NOW...WILL
KEEP OUT MENTION OF CONVECTION FOR NOW. GUIDANCE GENERALLY VFR
OVERNIGHT...BUT SOME MODELS ARE HINTING AT SOME STRATUS AND PATCHY
FOG ACRS THE NC PIEDMONT TOWARD DAYBREAK. CONFIDENCE STILL LOW...BUT
HAVE 6SM BR AND A SCT MVFR CLOUD MENTION. CONVECTIVE CHCS LOOK
BETTER SATURDAY...BUT EXPECTING MOST OF THAT ACTIVITY AFTER 18Z.

ELSEWHERE...SHOWERS AND TSTMS DEVELOPING NORTH OF KAVL AND
KHKY...WITH MORE DEVELOPMENT EXPECTED THRU THE AFTN HOURS. HAVE VCTS
AT BOTH SITES. IN THE UPSTATE...CHCS ARE LOWER SUCH THAT NO MENTION
OF TS WILL BE CARRIED WITH THESE TAFS. THERE IS ABOUT A 20% CHC...SO
NOT OUT OF THE QUESTION A FEW CELLS DEVELOP IN THE UPSTATE.
OTHERWISE...VFR CONDITIONS ARE EXPECTED THRU THIS EVENING WITH WEST
WINDS. OVERNIGHT...GUIDANCE SHOWS SIMILAR FOG POTENTIAL TO LAST
NIGHT...SO TRENDS WILL BE SIMILAR IN THE TAFS. KAVL WILL LIKELY HAVE
SOME FOG OVERNIGHT...AND KHKY HAS THE NEXT BEST CHC BASED ON
POTENTIAL FOR RAINFALL THIS AFTN/EVE. FOR SATURDAY...CONVECTIVE CHCS
INCREASE AS A COLD FRONT SAGS SOUTH INTO THE AREA. HAVE PROB30 AT
ALL SITES FOR END OF 18Z TAF PERIOD.

OUTLOOK...A SLOW-MOVING FRONT WILL STALL ACROSS THE AREA THRU THE
WEEKEND...BRINGING MORE WIDESPREAD RESTRICTIONS IN CLOUDS/PRECIP
EXPECTED AS WEEKEND WEARS ON. AN AMPLIFIED SYSTEM WILL DEVELOP
ACROSS THE DEEP SOUTH EARLY NEXT WEEK. THIS SYSTEM WILL LIKELY
SUPPORT LOW CEILINGS AND RAINFALL ACROSS THE REGION AT LEAST THROUGH
MID WEEK.

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...JAT
NEAR TERM...ARK/PM
SHORT TERM...JOH
LONG TERM...JAT
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
458 AM EDT FRI SEP 28 2012

GAZ026-028-029-SCZ010>014-019-290900-
FRANKLIN-HART-ELBERT-ANDERSON-ABBEVILLE-LAURENS-UNION SC-CHESTER-
GREENWOOD-
458 AM EDT FRI SEP 28 2012

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

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

GAZ010-017-018-NCZ033-035>037-048>053-056>059-062>065-068>072-082-
501>510-SCZ001>009-290900-
RABUN-HABERSHAM-STEPHENS-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-
458 AM EDT FRI SEP 28 2012

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

.DAY ONE...TODAY AND TONIGHT.

SCATTERED THUNDERSTORMS MAY DEVELOP TODAY AND TONIGHT...MAINLY
ACROSS THE AREA ALONG AND NORTH OF INTERSTATE 85. THE MAIN THREAT
FROM THE STORMS WILL BE FREQUENT CLOUD TO GROUND LIGHTNING. ONE OR
TWO OF THE STORMS COULD BECOME STRONG WITH GUSTY WINDS AND SMALL
HAIL.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
205 PM EDT FRI SEP 28 2012

NCZ501-502-281845-
CALDWELL MOUNTAINS-GREATER CALDWELL-
205 PM EDT FRI SEP 28 2012

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL CALDWELL COUNTY THROUGH
245 PM EDT...

AT 203 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR PATTERSON...OR 4 MILES NORTHWEST OF
LENOIR...MOVING EAST AT 10 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO
  PATTERSON...KINGS CREEK...LENOIR...HUDSON...GAMEWELL AND
  COLLETTSVILLE.

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

LAT...LON 3604 8136 3600 8132 3593 8134 3592 8135
      3589 8133 3582 8134 3587 8168 3605 8166
      3605 8139

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
223 PM EDT FRI SEP 28 2012

NCZ502>504-281915-
BURKE MOUNTAINS-GREATER BURKE-GREATER CALDWELL-
223 PM EDT FRI SEP 28 2012

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL BURKE AND SOUTHERN
CALDWELL COUNTIES THROUGH 315 PM EDT...

AT 219 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 3 MILES SOUTHWEST OF TABLE ROCK...OR 9 MILES
NORTHWEST OF MORGANTON...MOVING EAST AT 20 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO RUTHERFORD
  COLLEGE...LAKE RHODHISS...VALDESE...TABLE ROCK...SAWMILLS...
  RHODHISS...MORGANTON...LENOIR...ICARD...HUDSON...GRANITE FALLS...
  GLEN ALPINE...GAMEWELL...DREXEL...CONNELLY SPRINGS AND CAJAH'S
  MOUNTAIN.

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

LAT...LON 3569 8142 3568 8143 3571 8187 3573 8189
      3590 8189 3591 8174 3589 8173 3591 8170
      3593 8142

07

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
232 PM EDT FRI SEP 28 2012

NCZ035>037-281915-
ALEXANDER-DAVIE-IREDELL-
232 PM EDT FRI SEP 28 2012

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN ALEXANDER...
NORTHERN IREDELL AND WESTERN DAVIE COUNTIES THROUGH 315 PM EDT...

AT 229 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR LOVE VALLEY...OR 11 MILES NORTHEAST OF
TAYLORSVILLE...MOVING EAST AT 20 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO UNION
  GROVE...TURNERSBURG...SHEFFIELD...LOVE VALLEY AND HARMONY.

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

LAT...LON 3606 8055 3586 8057 3593 8111 3603 8110
      3607 8098

07