Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
807 PM EDT Sun Aug 12 2018

.SYNOPSIS...
A low level boundary will remain stalled across the Piedmont and aide
in developing afternoon showers and thunderstorms which will
linger into the evening. An upper-level disturbance will track
northeast the region late Monday leading to drier weather Tuesday
and Wednesday. Moisture levels increase Thursday through the end of
the week ahead of an approaching cold front.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 600 PM...Tstm chances through mid-evening will be confined
mainly to locales east of the Blue Ridge and NE of I-26 and there
also remains the likelihood of isolated strong storms producing stout
wind gusts and/or torrential rainfall. Later tonight, as an upper
low wobbles around the OH/PA border, vort energy remains progged to
pivot downstream of the cwfa. This should carry any lingering
convection east of the FA by late evening. Some mid and high clouds
will linger under the circulation of the upper low, but mountain
valleys will likely fog up overnight. Low temps will be about a
category above normal.

Monday, the upper low will wobble eastward bringing NVA and deep-
layer Q-vector divergence atop the FA. Dry air will also wrap in
from the west, with dewpts dipping into 60s for most of the area.
This all adds up to much less sbCAPE and a break from the active
convective pattern we've been in. Guidance does try to fire at least
a few isolated showers in the high terrain, and cannot rule out a
few showers or storm in the far eastern zones, depending on how fast
we dry out before peak heating. Temps will be near normal under
partly cloudy skies.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 2pm EDT Sunday: Fairly quiet short term forecast as region
will be between systems.  A few lingering showers are possible
Monday night over the mountains as upper wave exits, but these will
be on the decline as frontal boundary pushes moisture further
southeast.  Tuesday will see gradual height rises on the dry side of
upper system with convectively stable and capped air mass in place
by Tuesday evening.  Ridge builds over the area on Wednesday and
begins to move east by late Wednesday when some clouds and possibly
a few showers out west ahead of next system may be entering the
region. Conditions Tuesday and Wednesday will generally be clear and
seasonally normal with fairly light winds with a slight
northwesterly bias when not variable.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 300 PM EDT Sunday: Thursday PoPs are generally unchanged from
yesterday and overnight with a slower progression of the previously
advertised shortwave.  The slower forecast can be attributed to
additional retrogression of the large subtropical ridge into the
SE US and NE GoMex.

Diurnal PoPs on Friday have increased slightly over the mountains
closer to the approaching "cold" front and mid-level support
via the dampening shortwave, but guidance is also significantly
decreasing coverage over the Piedmont compared to yesterday, which
may be premature given height falls across the entire region in
advance of the shortwave trough and the lingering presence of
a lee trough. However, timing may be an issue over the Piedmont
as the better forcing may not arrive until after peak heating.
Let's see if a trend develops first before removing low-end chance
PoPs over the Piedmont.

Convective chances still are expected to increase over the Piedmont
on Saturday as the aforementioned weak cold front sags into the
area underneath a reinforced shortwave trough, although this too
appears to be about 6-12 hours slower than yesterday's forecast.
This too is a blend of a faster GFS solution and slower ECMWF
and Canadian guidance.  Given the proximity of upper support and
the presence of the weak surface convergence high-end chance PoPs
are maintained over the mountains while chance PoPs are maintained
further east through the weekend.  Throughout the extended, moisture
transport from the GoMex remains anemic as the source remains on
the western edge of the ridge axis and flow is weak.  The GFS is
suggesting lower total water content compared to yesterday but
plenty of in-situ moisture remains and it would not take much
flux to introduce PWs near 2" east of the mountains at any point.
Therefore, a localized heavy rain threat will persist at a minimum.

Temperatures will remain at or perhaps 1-3 degrees below normal
through the extended. Dewpoints will remain in the upper 60s
to lower 70s east of the mountains keeping humidity values high
through the period.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Isolated showers and tstms acrs the FA will
dissipate through 02z.  A period of localize,d variable flight
restrictions, a mix of fog and low clouds is likely to develop
during the pre-dawn hours and linger through mid-morning Monday.
Winds will be light through Monday morning then assume a westerly
direction Monday afternoon and increase to 6-8 kts. Developing
showers or thunderstorms should be of much less coverage than the
past few days and no mention of such will be carried in the tafs.

Outlook: Drier weather is expected for Tuesday and Wednesday, but
will be followed by a return of diurnal convection on Thursday and
Friday.

Confidence Table...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       High 100%     High  82%     High  83%     High 100%
KGSP       High 100%     High  99%     High 100%     High 100%
KAVL       High 100%     Med   78%     High  94%     High 100%
KHKY       High  96%     High  93%     High  94%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High  97%     High  97%     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...SBK
NEAR TERM...ARK/CSH
SHORT TERM...WJM
LONG TERM...JMP
AVIATION...ARK/CSH

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
604 PM EDT Sun Aug 12 2018

NCZ035>037-056-057-064-065-068>072-082-501>510-SCZ002-003-005>009-
012>014-132215-
Alexander-Iredell-Davie-Catawba-Rowan-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-Pickens Mountains-
Greenville Mountains-Greater Pickens-Greater Greenville-Spartanburg-
Cherokee-York-Laurens-Chester-
604 PM EDT Sun Aug 12 2018

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

.DAY ONE...Tonight.

There is the ongoing threat of thunderstorm development this evening.
A few of these storms could still become severe with damaging wind
gusts. Isolated flooding will also be possible. Any storm will be
capable of producing strong wind gusts, heavy rainfall, and cloud to
ground lightning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to forward any reports of large hail,
damaging winds, tornadoes, or flash flooding to our office.

GAZ010-017-018-026-028-029-NCZ033-048>053-058-059-062-063-SCZ001-004-
010-011-019-132215-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Avery-Madison-Yancey-
Mitchell-Swain-Haywood-Buncombe-Graham-Northern Jackson-Macon-
Southern Jackson-Oconee Mountains-Greater Oconee-Anderson-Abbeville-
Greenwood-
604 PM EDT Sun Aug 12 2018

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

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
625 PM EDT SUN AUG 12 2018

NCZ057-122245-
Rowan NC-
625 PM EDT SUN AUG 12 2018

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL ROWAN COUNTY UNTIL
645 PM EDT...

At 624 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles east of Salisbury, or over High Rock Lake, moving northeast at
15 mph.

Locations to be impacted include...
High Rock Lake.

Wind gusts up to 50 mph and half inch hail will be possible in these
areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.

High Rock Lake is in the path of this storm. Cloud to ground
lightning and gusty winds will create dangerous boating conditions.
Move to shore immediately.

&&

LAT...LON 3561 8036 3567 8039 3572 8033 3571 8032
      3570 8033 3568 8033 3567 8031 3563 8029
      3563 8027 3561 8024
TIME...MOT...LOC 2224Z 242DEG 12KT 3566 8030

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
730 PM EDT SUN AUG 12 2018

SCZ014-122345-
Chester SC-
730 PM EDT SUN AUG 12 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN CHESTER COUNTY
UNTIL 745 PM EDT...

At 730 PM EDT, Doppler radar was tracking a strong thunderstorm 12
miles southwest of Lancaster, or near Great Falls, moving east at 10
mph.

Locations to be impacted include...
Great Falls and Fishing Creek Reservoir.

Wind gusts up to 50 mph and pea size hail will be possible in these
areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.

&&

LAT...LON 3454 8088 3455 8104 3456 8104 3465 8100
      3468 8088 3467 8089 3465 8089 3464 8090
      3462 8089 3460 8089 3456 8087
TIME...MOT...LOC 2330Z 277DEG 9KT 3460 8095

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
750 PM EDT SUN AUG 12 2018

NCZ068-130015-
Cleveland NC-
750 PM EDT SUN AUG 12 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN CLEVELAND COUNTY
UNTIL 815 PM EDT...

At 750 PM EDT, Doppler radar was tracking a strong thunderstorm near
Shelby, moving east at 20 mph.

Locations to be impacted include...
Shelby, Patterson Springs and Boiling Springs NC.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3521 8164 3528 8166 3533 8142 3522 8138
TIME...MOT...LOC 2350Z 254DEG 17KT 3526 8157

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
807 PM EDT SUN AUG 12 2018

NCZ082-130030-
Union NC-
807 PM EDT SUN AUG 12 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN UNION COUNTY UNTIL
830 PM EDT...

At 807 PM EDT, Doppler radar was tracking a strong thunderstorm 15
miles southeast of Monroe, or 4 miles south of Sturdivants, moving
east at 20 mph.

Locations to be impacted include...
Sturdivants.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3488 8031 3481 8032 3481 8041 3487 8042
      3493 8031
TIME...MOT...LOC 0007Z 252DEG 16KT 3484 8035

LANE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
811 PM EDT SUN AUG 12 2018

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

0644 PM     TSTM WND DMG     NW ROCKWELL             35.55N 80.41W
08/12/2018                   ROWAN              NC   PUBLIC

            AT LEAST 2 TREES DOWN AND SEVERAL LARGE BRANCHES IN AND
            NEAR ROCKWELL.

&&

OUTLAW

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
821 PM EDT SUN AUG 12 2018

NCZ082-130045-
Union NC-
821 PM EDT SUN AUG 12 2018

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN UNION COUNTY UNTIL
845 PM EDT...

At 821 PM EDT, Doppler radar was tracking a strong thunderstorm 15
miles northeast of Monroe, or 10 miles north of Marshville, moving
east at 15 mph.

Locations to be impacted include...
New Salem.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3506 8029 3507 8041 3517 8043 3517 8042
      3516 8041 3518 8037 3517 8036 3518 8033
      3517 8032 3519 8030 3519 8029 3520 8028
TIME...MOT...LOC 0021Z 252DEG 15KT 3513 8033

LANE