Flash Flood and Hail in North Carolina, July 8, 2017

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
250 PM EDT Sat Jul 8 2017

.SYNOPSIS...
Seasonably warm temperatures and afternoon showers and thunderstorms
will continue as a front pushes through the area late tonight. Drier
air will build in Sunday and Monday with more humid and unsettled
weather expected through the second half of next week as the frontal
boundary creeps back into the area from the south. A more
substantial system will move through the area near the end of next
week.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 245 PM EDT Saturday:  Convection firing mainly over the
higher terrain as of 18Z, but suspect storms will only get stronger
and more numerous from there as a short wave comes into play
as it crosses the region through early evening. Downslope flow
immediately to the lee of the Blue Ridge might put a damper on
some development, but cu field continues to blossom in the I-85
corridor and east, so we should not have any problems with the
storm environment there. Speaking of which, latest mesoanalysis
shows sbCAPE in the 1500-3000 J/kg range, thus we are well on our
way to having moderate instability for the afternoon ahead of a
boundary dropping down from the N. Meanwhile, dCAPE greater than
800 J/kg has developed across the entire fcst area. Think we have
just about all the ingredients we need for scattered to numerous
thunderstorms this afternoon with a good chance that several
of them will go severe with wind damage the main threat. Better
shear means a better chance for organization as cold pools merge
and expand east of the mtns. Agree with SPC Day 1 Slight Risk over
the wrn Piedmont of NC as that area stands a good chance of seeing
severe wind producing multicells this afternoon.

The passage of the short wave this evening should carry the
bulk of the convection to the s/e of the fcst area by around
sunset, followed by the passage of the surface boundary. Some
activity could linger on the SE fringe into the late evening,
but otherwise, drier air will spill in across the region behind
the boundary. Some mtn valley fog is expected around daybreak
Sunday, but otherwise it should be a cooler day, maybe a few deg
on the cool side of normal. However, the air mass should be drier,
which hopefully will make it not as uncomfortable as the past few
days. An isolated shower or storm could develop near the fall line,
so a slight chance was retained on the southeast fringe.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 130 PM Saturday: The upper trough over the eastern CONUS will
deamplify Monday thru Tuesday, as a subtropical ridge reassert
itself into the Southeast. At the surface, a Bermuda high pattern
will gradually set back up across the region. It will take a couple
days for moisture and instability to return to typical mid-July
levels. So PoPs will remain below climatological coverage for mainly
diurnal convection. Temps will be near or slightly above normal.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 100 PM EDT Saturday: The medium range remains in a pretty
typical July holding pattern with chances of scattered convection
each afternoon. Upper heights will rise briefly on Wednesday, though
continued moist southerly flow courtesy of an elongated Bermuda high
and some slight upper forcing accompanying a weak upper shortwave
will likely still lead to scattered diurnal convection. Upper
troughing begins to take shape again for the eastern CONUS on
Thursday, and a stalled remnant frontal boundary will provide a
focus for diurnal convection. The upper trough deepens with a
shortwave approaching our CWA by Friday, likely leading to sustained
showers and thunderstorms overnight in a more non-diurnal pattern.
Decent instability should develop each day, so a few pulse-type
severe storms are possible. Temperatures will begin the period just
above average, and will fall to near average as heights fall aloft.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
At KCLT and Elsewhere:  VFR through the period at all sites with
the possible exception of afternoon MVFR convection, as well as
early morning MVFR fog restrictions at KAVL Sunday morning. The
convection-allowing model guidance suggests a good chance of
semi-organized storms developing over the mtns and then moving
east across the region through 00Z...thus all sites but KHKY get
a four-hour TEMPO to account for this. A Well mixed boundary layer
will keep wind SW through the afternoon with some gusts possible,
until sfc boundary moves through in the early evening to bring
direction around to NW for the rest of the evening, then light N
overnight. On Sunday, expect only high level clouds with a light
NE wind.

Outlook: Quiet conditions will prevail on Sunday afternoon with a
stable air mass behind the cold front.  Chances for restrictions
will gradually increase into next week thanks to diurnal showers
and thunderstorms, as well as overnight/morning fog.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High  91%     High  94%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High 100%     High 100%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

SYNOPSIS...Carroll
NEAR TERM...PM
SHORT TERM...ARK
LONG TERM...Carroll
AVIATION...PM

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
353 PM EDT Sat Jul 8 2017

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-092000-
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-
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-Chester-Greenwood-
353 PM EDT Sat Jul 8 2017

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.

.DAY ONE...This Afternoon and Tonight.

A cold front will continue to push across the western Carolinas and
Northeast Georgia through this evening. Scattered to numerous
thunderstorms will continue to develop along and ahead of this
front. With the added lift...some of these storms will become quite
strong or severe. The main threats will be damaging winds and large
hail...along with cloud to ground lightning.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

..Sunday...No hazardous weather is expected at this time.
..Monday...No hazardous weather is expected at this time.
..Tuesday...No hazardous weather is expected at this time.
..Wednesday...No hazardous weather is expected at this time.
..Thursday...No hazardous weather is expected at this time.
..Friday...No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Skywarn spotters are requested to forward any reports of large hail
and damaging winds to our office.

ARK

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
313 PM EDT SAT JUL 8 2017

NCZ036-037-081945-
Davie NC-Iredell NC-
313 PM EDT SAT JUL 8 2017

...A STRONG THUNDERSTORM WILL IMPACT DAVIE AND NORTHEASTERN IREDELL
COUNTIES UNTIL 345 PM EDT...

At 313 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles northwest of Mocksville, or 4 miles south of Courtney, moving
east at 25 mph.

Locations to be impacted include...
Mocksville, Bermuda Run, Sheffield, Advance, Farmington and Fork
Church.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

LAT...LON 3589 8041 3588 8041 3589 8049 3590 8073
      3605 8074 3604 8049 3606 8046 3603 8044
      3600 8041 3599 8042 3596 8038 3589 8037
TIME...MOT...LOC 1913Z 269DEG 22KT 3600 8065

WJM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
317 PM EDT SAT JUL 8 2017

NCZ051-058-062-081945-
Graham NC-Swain NC-Macon NC-
317 PM EDT SAT JUL 8 2017

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT
NORTHWESTERN MACON...SOUTHWESTERN SWAIN AND GRAHAM COUNTIES UNTIL 345
PM EDT...

At 317 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning 7 miles west of Robbinsville, or 4 miles west of
Town Of Santeetlah, moving east at 30 mph.

Locations to be impacted include...
Bryson City, Robbinsville, Town Of Santeetlah, Smoky Mountains-Deep
Creek, Lake Santeetlah, Fontana Lake, Fontana Village, Smoky
Mountains-Fontana Area, Wesser and Stecoah.

In addition to intense lightning, wind gusts up to 40 mph and pea
size hail will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. Do not take a shower or bath. Try to unplug unnecessary
appliances before the storm approaches.

&&

LAT...LON 3537 8401 3541 8402 3543 8400 3550 8344
      3523 8341 3523 8369 3526 8371 3524 8376
      3526 8379 3525 8385 3524 8388 3524 8401
      3527 8401 3529 8403 3535 8403
TIME...MOT...LOC 1917Z 265DEG 26KT 3534 8394

WJM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
332 PM EDT SAT JUL 8 2017

NCZ509-510-082000-
Polk Mountains NC-Eastern Polk NC-
332 PM EDT SAT JUL 8 2017

...A STRONG THUNDERSTORM WILL IMPACT POLK COUNTY UNTIL 400 PM EDT...

At 331 PM EDT, Doppler radar was tracking a strong thunderstorm near
Columbus, moving east at 15 mph.

Locations to be impacted include...
Columbus, Tryon, Mill Spring, Green Creek and Lake Adger.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

LAT...LON 3540 8213 3534 8208 3534 8206 3527 8200
      3526 8197 3522 8196 3520 8197 3519 8205
      3520 8230 3530 8234 3531 8233 3531 8231
      3536 8228 3540 8219 3541 8216
TIME...MOT...LOC 1931Z 250DEG 14KT 3527 8224

WJM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
336 PM EDT SAT JUL 8 2017

NCZ064-065-SCZ003-082000-
Transylvania NC-Henderson NC-Greenville Mountains SC-
336 PM EDT SAT JUL 8 2017

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN TRANSYLVANIA...
SOUTHWESTERN HENDERSON AND NORTHWESTERN GREENVILLE COUNTIES UNTIL 400
PM EDT...

At 335 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles southwest of Brevard, or near Rosman, moving east at 15 mph.

Locations to be impacted include...
Brevard, Etowah, Rosman, Jones Gap State Park, Dupont State Forest,
Caesars Head State Park, Laurel Park, Mills River, Looking Glass and
Flat Rock.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

LAT...LON 3539 8253 3514 8242 3507 8278 3508 8278
      3509 8279 3507 8283 3507 8284 3523 8291
TIME...MOT...LOC 1935Z 250DEG 14KT 3518 8279

WJM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
351 PM EDT SAT JUL 8 2017

NCZ064-065-SCZ002-003-082015-
Transylvania NC-Henderson NC-Pickens Mountains SC-
Greenville Mountains SC-
351 PM EDT SAT JUL 8 2017

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT
SOUTHEASTERN TRANSYLVANIA...SOUTHWESTERN HENDERSON...NORTHWESTERN
GREENVILLE AND NORTHERN PICKENS COUNTIES UNTIL 415 PM EDT...

At 351 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning 13 miles northwest of Pickens, or 6 miles south of
Rosman, moving east at 15 mph.

Locations to be impacted include...
Rosman, Jocassee Gorges, Jones Gap State Park, Table Rock State Park,
Caesars Head State Park, Slater-Marietta, Dupont State Forest, Keowee
Toxaway State Park, Gorges State Park and Lake Jocassee.

In addition to intense lightning, wind gusts up to 40 mph will be
possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. Do not take a shower or bath. Try to unplug unnecessary
appliances before the storm approaches.

&&

LAT...LON 3512 8293 3522 8253 3499 8249 3497 8256
      3495 8260 3494 8289 3504 8291 3505 8290
      3505 8292
TIME...MOT...LOC 1951Z 261DEG 13KT 3505 8283

WJM

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
406 PM EDT SAT JUL 8 2017

NCZ056-068-069-504-508-082030-
Greater Rutherford NC-Cleveland NC-Lincoln NC-Greater Burke NC-
Catawba NC-
406 PM EDT SAT JUL 8 2017

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN CATAWBA...
NORTHEASTERN RUTHERFORD...NORTHWESTERN LINCOLN...NORTH CENTRAL
CLEVELAND AND SOUTHEASTERN BURKE COUNTIES UNTIL 430 PM EDT...

At 406 PM EDT, Doppler radar was tracking a strong thunderstorm 6
miles south of Morganton, or 4 miles northwest of South Mountains
State Park, moving east at 15 mph.

Locations to be impacted include...
Morganton, Hickory, Longview, Valdese, Icard, Hildebran, Connelly
Springs, Rutherford College, Glen Alpine and Hickory Regional
Airport.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

LAT...LON 3576 8140 3576 8138 3577 8137 3577 8136
      3551 8136 3554 8180 3573 8180 3577 8142
TIME...MOT...LOC 2006Z 270DEG 15KT 3565 8172

WJM