Damaging Wind in North Carolina, July 31, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
942 PM EDT TUE JUL 31 2012

.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD OVER THE REGION TONIGHT AND LINGER
THROUGH THE WEEKEND. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE
REGION ON MONDAY FOLLOWED BY ANOTHER HIGH PRESSURE BUILDING IN FROM
THE NORTH ON TUESDAY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 9 PM...A QUICK UPDATE TO ADJUST POP/WX TO LINE UP BETTER WITH
MCS THAT IS TRACKING INTO THE NC MTNS. THE MCS IS EXPECTED TO LOSE
STEAM AS IT IS BROKEN UP IN THE HIGH TERRAIN AND ENCOUNTERS LESS
INSTBY. THE REMNANT OUTFLOW MAY INITIATE MORE CONVECTION AS IT
CROSSES THE CWFA NW-SE...SO KEEP AT LEAST CHC POP AHEAD OF IT THRU
THE REST OF THE EVENING.

AS OF 8 PM...ANOTHER POTENT SHORTWAVE WAS SEEN ON WATER VAPOR AND
RAP ANALYSIS ENTERING THE SRN APPALACHIANS...KICKING OFF PLENTY OF
CONVECTION JUST UPSTREAM OF THE NRN MTNS. THE 23Z LAPS CAPE FIELD
SHOWS 2500+ J/KG CAPE AXIS ACRS THE GREAT VLY AND WEST...WITH VERY
LITTLE CAPE ACRS THE NRN MTNS. SURE ENUF...CONVECTION SEEMS TO BE
WEAKENING AS THEY APPROACH THE CWFA. STILL HAVE INCREASED POP ACRS
THE NRN MTNS AS THE DISSIPATING CONVECTION ROLLS IN. THE FCST SNDGS
OF THE NAM AND GFS SHOW TALL/SKINNY CAPE THRU THE EVE...AS THE
SHORTWAVE PASSES THRU. SO PROBABLY WILL BE AT LEAST ISOLD-SCATTERED
SHRA AND POSSIBLY A FEW WEAK TSTMS THIS EVE. A NON-ZERO EXCESSIVE
RAIN/FLOOD THREAT WILL CONTINUE GIVEN PWATS STILL AROUND 1.75-2.00"
AND SLOW STORM MOTIONS.

PREVIOUS DISCUSSION...
WATER VAPOR IMAGERY SHOWS STRONGEST VORT LOBE PUSHING INTO THE NW
MTNS WITH BEST FORCING AHEAD OF IT...KICKING OFF WIDESPREAD SHWRS
AND ISOLD TSTMS...ESP ACROSS THE FOOTHILLS AND PIEDMONT. WITH
OVERCAST SKIES...SHWRS AND COOLER AIR ACROSS THE CWA...THE LATE AFTN
TEMP FCST WAS SCALED BACK. CAPE VALUES HAVE REMAINED QUITE LOW ALSO
SO HAVE LIMITED TS MENTION TO THE CHC RANGE. AREAS OF HEAVY RAIN IN
WHAT APPEARS TO BE A VERY LOW-TOPPED MCS SHOULD CONTINUE TO CAUSE
ISOLD LOW-END FLOODING ISSUES UNTIL THE SYSTEM MOVES E OF THE AREA
LATER TODAY...AND RAINFALL RATES AROUND CLT WILL HAVE TO BE WATCHED.
CONVECTION WILL TAPER OFF THIS EVE BUT ISOLD SHWRS ARE EXPECTED TO
LINGER LATE TONIGHT...ESP OVER THE SE CWA. MRNG LOWS WILL BE NEAR TO
SLIGHTLY BELOW AVG AND AREAS OF FOG ARE LIKELY...ESP NEAR LAKES AND
RIVERS. THE SHORTWAVE TRACKS WELL E WED BUT ANOTHER WEAK IMPULSE
WILL DROP DOWN OVER THE REGION IN CONTINUING NW FLOW ALOFT. WITH
MOISTURE PROFILES BEING MORE SHALLOW...AND LESS UPPER FORCING...
HAVE CHC POPS ACROSS MOST OF THE CWA THU AFTN. HIGHS WILL BE NEAR
AVG.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 2 PM EDT TUE...RATHER PERSISTENT E COAST TROUGHING WILL REMAIN
IN PLACE THROUGH THU...WITH HEIGHTS FORECAST TO SLOWLY RISE ON FRI.
POORLY RESOLVED WEAK SHORT WAVES IN THE MODELS MAKE IT DIFFICULT TO
DISPLAY TOO MUCH CONFIDENCE IN ANY ONE FEATURE. BOTH THE GFS AND
NAM DO SHOW SOME MODEL RESPONSE EARLY WED NIGHT OVER THE PIEDMONT AS
AN APPARENT SHORT WAVE MOVES BY AND A WEAKENING BOUNDARY PROVIDES
SOME LOW LEVEL CONVERGENCE. THEREFORE...WILL HAVE SOME SCATTERED
TYPE POPS IN THAT AREA DURING THE EVENING HOURS. DRYER AIR ARRIVES BY
LATE WED NIGHT AS WEAK HIGH PRESSURE BUILDS IN FROM THE NW.
THURSDAY SHOULD FEATURE CONSIDERABLE SUNSHINE AND HOT AFTERNOON
TEMPS. MODEL SOUNDINGS IN BUFKIT SHOW CONSIDERABLE INSTABILTY BY
LATE THU AFTERNOON AND SOME MODEL QPF RESPONSE DURING THE EVENING
OVER THE PIEDMONT IN THE WEAKLY CONVERGENT FLOW. HENCE...WILL ADD
SOME WIDELY SCATTERED TYPE POPS FOR THAT TIMEFRAME...BUT ENDIGN ANY
CONVECTIVE THREAT BY MIDNIGHT. ON FRIDAY...ANOTHER WEAK SHORT WAVE
DURING THE AFTERNOON HAS THE POTENTIAL TO TRIGGER MORE WIDESPREAD
CONVECTION SO WILL HAVE SOLID SCATTERED POPS FOR THAT. LEANED TOWARD
THE BIAS CORRECTED GMOS FOR MAX/MIN TEMPS AS IT HAS BEEN PERFORMING
VERY WELL. TEMPS THROUGH THE SHORT TERM WILL BE A CATEGORY OR SO
ABOVE AVERAGE.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 115 PM EDT TUESDAY...THE UPPER PATTERN WILL TRANSITION OVER
THE WEEKEND FROM A MEAN TROUGH OVER THE SE U.S. TO A FLAT RIDGE.
THEREFORE...THE ACTIVE NORTHERN STREAM WAVES WILL REMAIN NORTH OF
THE AREA. THIS PATTERN FAVORS TYPICAL SUMMERTIME SENSIBLE WEATHER.
THEREFORE...WE A EXPECT A STRONG DIURNAL PATTERN TO THE DAILY
CONVECTION. HOWEVER WITH WEAKLY UPSLOPE FLOW...SOME NOCTURNAL
SHOWERS ARE NOT OUT OF THE QUESTION OVER THE MOUNTAINS. TEMPERATURES
ARE EXPECTED TO REMAIN ABOUT A CATEGORY ABOVE AVERAGE SAT AND SUN.

A MODEL CONSENSUS INDICATES THAT A VIGOUROUS WAVE WILL MOVE ACROSS
THE GREAT LAKES SUN THROUGH MON WHICH WILL CAUSE HEIGHTS TO
GRADUALLY FALL AGAIN ACROSS THE SE. A SHORTWAVE IS EXPECTED TO
CROSS THE AREA ON MON WHILE AT THE SURFACE A COLD FRONT WILL
APPROACH FROM THE NW LATE IN THE DAY AND MOVE INTO THE AREA ON MON
NIGHT. HPC KEEPS THE FRONT NORTH OF THE AREA INTO TUE...BUT ECM
TAKES THE BOUNDARY SOUTH OF THE FORECAST AREA ON TUE WITH THE GFS
LAYING THE FRONT OVER THE AREA. THESE TRIGGERING MECHANISMS SUPPORT
MORE SOLID POPS IN THE FORECAST FOR MON INTO TUE. MAX TEMPS WILL
CONTINUE ABOVE AVERAGE WITH 80S MTNS AND LOWER 90S PIEDMONT.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...PLENTY OF MID AND HIGH CLOUDS EXPECTED THRU MOST OF THE
NIGHT...AS ANOTHER SHORTWAVE TRACKS THRU THE AREA. COULD EVEN BE A
FEW SHRA AND TSRA LATER THIS EVENING...BUT CONFIDENCE TOO LOW TO
MENTION IN THE TAF ATTM. WITH PLENTY OF LLVL MOISTURE FROM EARLIER
RAIN...MAY SEE SOME STRATUS AND/OR FOG. VERY LOW CONFIDENCE GIVEN
POOR GUIDANCE. KEEPING HEDGE 5SM AND FEW010 LATE TNGT. ON
WEDNESDAY...DRIER AIR WILL WORK IN FROM THE WEST...BUT SCATTERED MTN
CONVECTION IS EXPECTED...WITH SOME ACTIVITY POSSIBLY TRACKING SE
ACRS THE PIEDMONT. ENUF CONFIDENCE FOR PROB30 TS. WINDS WILL BE LGT
THRU THE PD.

ELSEWHERE...LOW CONFIDENCE FCST...AS VERY MOIST AIR MASS REMAINS IN
PLACE...WHILE AN UPPER DISTURBANCE TRACKS THRU POSSIBLY KICKING OFF
SOME SHRA AND TSRA LATE THIS EVE. KAVL HAS THE HIGHEST CHC OF
TS...SO HAVE VCTS. REST OF THE SITES WILL LEAVE OUT FOR NOW. THE
BIGGER ISSUE IS HOW MUCH MID-HIGH CLOUDS WILL LINGER OVERNIGHT...AND
WILL THERE BE ENUF RADIATIONAL COOLING FOR FOG/STRATUS. GIVEN SO
MUCH UNCERTAINTY IN THE GUIDANCE...OPTED TO MAKE FEW CHANGES TO THE
00Z TAFS. MAY MAKE QUICK ROUND OF AMD SHORTLY ONCE MORE TRENDS CAN
BE ESTABLISHED. WHATEVER FOG/STRATUS DEVELOPS...SHOULD LIFT BY MID
MRNG. SCATTERED SHRA/TSRA EXPECTED IN THE MTNS...WITH SOME ACTIVITY
MOVING SE ACRS THE PIEDMONT WED AFTN.

OUTLOOK...SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS WILL
SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.

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...ARK/RB
SHORT TERM...LG
LONG TERM...LG
AVIATION...ARK/RB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
843 PM EDT TUE JUL 31 2012

NCZ051-052-058-020045-
SWAIN-HAYWOOD-GRAHAM-
843 PM EDT TUE JUL 31 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...TONIGHT.

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE IN THE FORECAST
FOR TONIGHT. THE MAIN THREAT FROM ANY STORMS THAT DO DEVELOP WILL BE
CLOUD TO GROUND LIGHTNING AND LOCALLY HEAVY RAINFALL. THERE IS A
LINE OF STORMS ACROSS THE GREAT VALLEY IN EASTERN TENNESSEE WHICH
MAY PRODUCING DAMAGING WINDS IN THE SMOKEY MOUNTAINS THIS
EVENING.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

GAZ010-017-018-026-028-029-NCZ033-035>037-048>050-053-056-057-059-
062>065-068>072-082-501>510-SCZ001>014-019-020045-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-ALEXANDER-
IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-BUNCOMBE-CATAWBA-ROWAN-
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-
843 PM EDT TUE JUL 31 2012

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

.DAY ONE...TONIGHT.

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE IN THE FORECAST
FOR TONIGHT. THE MAIN THREAT FROM ANY STORMS THAT DO DEVELOP WILL BE
CLOUD TO GROUND LIGHTNING AND LOCALLY HEAVY RAINFALL.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
906 PM EDT TUE JUL 31 2012

NCZ051-052-010145-
HAYWOOD-SWAIN-
906 PM EDT TUE JUL 31 2012

...STRONG THUNDERSTORMS WILL AFFECT NORTHERN SWAIN AND NORTHWESTERN
HAYWOOD COUNTIES THROUGH 945 PM EDT...

AT 904 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 8 MILES SOUTHWEST OF
WATERVILLE TO 4 MILES SOUTHEAST OF TOWNSEND...MOVING SOUTH AT 30 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO
  WATERVILLE...SMOKEMONT AND NEWFOUND GAP.

SMALL HAIL...WIND GUSTS UP TO 40 MPH AND TORRENTIAL RAIN ARE EXPECTED
WITH THESE STORMS.

FREQUENT LIGHTNING IS OCCURRING WITH THESE 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 3553 8388 3553 8383 3557 8377 3558 8360
      3557 8349 3567 8334 3566 8330 3573 8324
      3573 8321 3575 8318 3579 8306 3564 8303
      3555 8310 3545 8372 3547 8392

CSH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
927 PM EDT TUE JUL 31 2012

NCZ052-010200-
HAYWOOD-
927 PM EDT TUE JUL 31 2012

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL HAYWOOD COUNTY THROUGH
1000 PM EDT...

AT 927 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR COVE CREEK...OR 10 MILES NORTH OF
WAYNESVILLE...MOVING SOUTHEAST AT 15 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  LAKE JUNALUSKA...
  WAYNESVILLE...
  CANTON...

WIND GUSTS OF 40 TO 50 MPH 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 3564 8287 3563 8285 3562 8285 3563 8282
      3562 8281 3557 8277 3556 8278 3555 8277
      3542 8303 3559 8310 3572 8291

CSH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
935 PM EDT TUE JUL 31 2012

NCZ051-059-010200-
NORTHERN JACKSON-SWAIN-
935 PM EDT TUE JUL 31 2012

...STRONG THUNDERSTORMS WILL AFFECT NORTHERN JACKSON AND SOUTHEASTERN
SWAIN COUNTIES THROUGH 1000 PM EDT...

AT 934 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 3 MILES WEST OF
MAGGIE VALLEY TO BRYSON CITY...MOVING SOUTH AT 30 MPH.

THESE STORMS WILL IMPACT LOCATIONS NEAR...
  ALARKA...
  BALSAM...

WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS.

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 3546 8360 3558 8318 3555 8316 3551 8318
      3549 8314 3546 8313 3546 8310 3540 8304
      3533 8335 3532 8344 3531 8346 3529 8354
      3530 8355

CSH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
954 PM EDT TUE JUL 31 2012

NCZ052-053-010230-
BUNCOMBE-HAYWOOD-
954 PM EDT TUE JUL 31 2012

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN HAYWOOD AND
SOUTHWESTERN BUNCOMBE COUNTIES THROUGH 1030 PM EDT...

AT 951 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES SOUTHEAST OF CANTON...OR 10 MILES EAST OF
WAYNESVILLE...MOVING SOUTHEAST AT 20 MPH.

THIS STORM WILL IMPACT LOCATIONS NEAR...
  CRUSO...

WIND GUSTS UP TO 40 MPH 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 3545 8264 3545 8266 3546 8267 3545 8271
      3542 8275 3541 8274 3538 8279 3536 8280
      3529 8292 3542 8302 3561 8281

CSH