Severe Thunderstorm Warning 237, NWS Greenville-Spartanburg, SC

894 
WWUS52 KGSP 212123
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
523 PM EDT SAT JUL 21 2018

NCC023-111-161-212145-
/O.CON.KGSP.SV.W.0237.000000T0000Z-180721T2145Z/
McDowell NC-Rutherford NC-Burke NC-
523 PM EDT SAT JUL 21 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EDT
FOR SOUTHEASTERN MCDOWELL...NORTHEASTERN RUTHERFORD AND SOUTHWESTERN
BURKE COUNTIES...

At 522 PM EDT, a severe thunderstorm was located 8 miles south of
Marion, moving east at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor hail damage to vehicles is expected. Expect wind 
         damage to trees and power lines.

Locations impacted include...
Sugar Hill, Thermal City, Glenwood, Sunshine, Fero, Dysartsville,
Union Mills and Shingle Hollow.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A few trees and power lines will be blown down in the warned area.
Hail can cause major property damage, especially to vehicles. Seek
shelter inside an interior room.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT...LON 3549 8214 3563 8212 3565 8176 3542 8177
TIME...MOT...LOC 2122Z 274DEG 23KT 3555 8199 

HAIL...1.00IN
WIND...60MPH
 
$$

08

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
240 PM EDT Sat Jul 21 2018

.SYNOPSIS...
A broad upper low will settle across the Deep South through early
next week. This low will remain nearly stationary through midweek
and support moist unsettled weather across the region.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 2 PM: Water vapor imagery and RAP heights placed the 500 mb
closed low center near the IL/IN/MI border this afternoon, with
drier mid-level air wrapping around the associated trough and across
the western Carolinas and northeast Georgia. Very good insolation
developed late this morning into this afternoon behind the departing
daybreak rain areas, and LAPS surface based CAPE values have
gradually returned to 1500 to 2500 J/kg across northeast GA and the
western Upstate. RAP and NAM profiles are very unstable this
afternoon, especially across our southern parts, where sbCAPE values
reach some 3000 to 4000 J/kg. The convection-allowing models have
not been terribly consistent on placement or timing, but the general
consensus is that enough triggering will take place as vorticity
lobes round the trough axis to generate scattered to numerous
thunderstorms later this afternoon and this evening. These
thunderstorms will grow in an enviroment with 7+ deg C/km mid-level
lapse rates and approximately 30 to 35 kt of sfc-6 km bulk shear.
This should be sufficient to warrant a Slight risk of severe
thunderstorms across our southern half, with a Marginal risk across
the northern part. Rotating updrafts will support mainly a damaging
wind and large hail threat. The consensus HRRR/NAMnest solution has
mountain trigging overcoming a weak cap circa 19Z, with activity
then developing and spreading quickly east of the mountains through
evening, moving east of the I-77 corridor by midnight. PoPs will
generally follow this trend.

Otherwise, the vertically stacked low pressure system will slowly
pivot southward toward the Ohio River Valley later tonight through
Sunday. Q-vector divergence will continue east of the deepening
trough axis mainly along the I-40 corridor. Reasonably steep 6 to
6.5 deg C/km lapse rates continue on Sunday east of the upper
trough. This will warrant at scattered south to numerous north
coverage again, with mainly a diurnal focus Sunday afternoon.
Temperatures should be at least a category below climo Sunday
afternoon.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 130 PM EDT Saturday: Active weather is likely to continue for
the period from Sunday night through Tuesday. The synoptic scale
feature of interest acrs the eastern CONUS will be the slowly
filling and southward sinking closed upper low.  With the mean
southerly flow atop the region deepening on Monday, expect an influx
of higher PWAT values leading to numerous if not widespread
diurnally enhanced deep convection with a heavy rain possibility
especially from the Blue Ridge to the piedmont. Widespread clouds
and showers should aid in max temperatures topping out around 5 deg
F below climo. It does not look like the sensible wx will change
very much through Tuesday, lingering rich PWAT values and a broad
SSEly flow feeding moisture into the Southern Appalachians. Expect
another day of deep convection becoming numerous to widespread with
the ongoing chance of locally excessive rainfall.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 115 PM Saturday: A weakening ulvl trof will linger over the
region thru the first half of the ext range before becoming sheared
out Fri into Sat. This synoptic scenario is well agreed upon by the
op models with the GFS holding onto a pocket of stronger vort energy
a little longer into Fri. At the sfc...broad low pressure will allow
for continued e/ly Atl moist flux early Wed before the deep layered
flow calms and becomes sw/ly in the lower levels Wed night thru the
period. This will lower any flooding potential as sustained mech lift
is reduced...however PWAT values will remain quite high allowing for
high rainfall rates associated with afternoon pulse convec. With
high cloud cover and decent coverage of precip...max temps will
remain a cat or so below normal with normal levels likely returning
Fri/Sat. Mins will remain a little abv normal each morning.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
At KCLT and Elsewhere: Convection is off to a very slow start this
afternoon as a weak cap remains in place in the profiles. Triggering
should force convection earliest over the mountains around 19Z, with
coverage growing eastward through the late afternoon and evening
hours. All locations will see TEMPO TSRA at some point in the 20Z to
22Z period, with gusts added given the potential for strong
updrafts/downdrafts. Considering the near surface moisture, heating
is producing some MVFR level clouds this afternoon in southwest
parts, but these should rise quickly to VFR levels with any
additional restrictions confined to thunderstorms. Expect mainly
southwest winds, with low end gusts at times, and a shift to NW flow
at KAVL late. Showers should return from KAVL to KHKY a bit earlier
on Sunday given the trough axis setting up to the west.

Outlook: An active/wet period is expected to continue from late
Sunday through the middle part of next week as a slow-moving storm
system impacts much of the East. Numerous showers and thunderstorms
are expected during this period. While there will likely be an
afternoon/evening peak in coverage on most days, higher-than-normal
chances will also exist during the overnight and morning hours.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     High 100%     High  95%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     Med   66%     High  90%
KHKY       High 100%     High 100%     High  97%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High  99%     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...SBK
NEAR TERM...HG
SHORT TERM...CSH
LONG TERM...SBK
AVIATION...HG

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
415 PM EDT Sat Jul 21 2018

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-222015-
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-
415 PM EDT Sat Jul 21 2018

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

.DAY ONE...Tonight.

Thunderstorms will continue to develop and expand in coverage across
the region into this evening. Some of these storms may become
severe. The most likely hazards will be damaging winds, large hail,
frequent lightning, and minor flooding from heavy rainfall. An
isolated tornado will also be possible, mainly east of the Blue
Ridge.

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

..Sunday...No hazardous weather is expected at this time.
..Monday...Heavy rain possible. A persistent moist southeasterly
flow will increase the risk for heavy rainfall across the area
starting late Monday and continuing through Wednesday.
..Tuesday...Heavy rain possible.
..Wednesday...Heavy rain possible.
..Thursday...No hazardous weather is expected at this time.
..Friday...No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
412 PM EDT SAT JUL 21 2018

NCZ065-509-510-SCZ003-212045-
Henderson NC-Polk Mountains NC-Eastern Polk NC-
Greenville Mountains SC-
412 PM EDT SAT JUL 21 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN HENDERSON...
SOUTHERN POLK AND NORTHEASTERN GREENVILLE COUNTIES UNTIL 445 PM
EDT...

At 412 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles west of Columbus, or over Saluda, moving east at 15 mph.

Locations to be impacted include...
Columbus, Tryon, Saluda, Dana, Mill Spring, Gowensville, North Saluda
Reservoir, Tuxedo, Glassy Mountain and East Flat Rock.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.

&&

LAT...LON 3530 8204 3519 8209 3519 8222 3508 8222
      3519 8246 3535 8238
TIME...MOT...LOC 2012Z 290DEG 13KT 3525 8234

RWH

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
429 PM EDT SAT JUL 21 2018

NCZ065-507>510-212100-
Greater Rutherford NC-Henderson NC-Polk Mountains NC-
Rutherford Mountains NC-Eastern Polk NC-
429 PM EDT SAT JUL 21 2018

...A CLUSTER OF THUNDERSTORMS WILL IMPACT CENTRAL RUTHERFORD...
NORTHEASTERN HENDERSON AND CENTRAL POLK COUNTIES UNTIL 500 PM EDT...

At 429 PM EDT, Doppler radar indicated a cluster of thunderstorms
along a line extending from 7 miles west of Rutherfordton to 6 miles
northeast of Hendersonville, and moving southeast at 15 mph.

Locations to be impacted include...
Rutherfordton, Columbus, Fletcher, Chimney Rock State Park, Bat Cave,
Mill Spring, Edneyville, Henrietta, Lake Adger and Dana.

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.

Dime to nickel size hail can cause considerable damage to vehicles.
Consider moving vehicles to a covered storage area before the storm
arrives.

&&

LAT...LON 3525 8178 3526 8236 3544 8253 3545 8247
      3546 8244 3547 8240 3546 8237 3548 8237
      3549 8230 3546 8225 3549 8223 3550 8221
TIME...MOT...LOC 2029Z 310DEG 15KT 3538 8210 3541 8241

08

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
455 PM EDT SAT JUL 21 2018

NCZ068-508-212130-
Greater Rutherford NC-Cleveland NC-
455 PM EDT SAT JUL 21 2018

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN RUTHERFORD AND
NORTHWESTERN CLEVELAND COUNTIES UNTIL 530 PM EDT...

At 455 PM EDT, Doppler radar was tracking a strong thunderstorm 6
miles north of Rutherfordton, moving east at 30 mph.

Locations to be impacted include...
Bostic, Polkville, Sunshine, Thermal City and Union Mills.

Wind gusts up to 45 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.

Dime to nickel size hail can cause considerable damage to vehicles.
Consider moving vehicles to a covered storage area before the storm
arrives.

&&

LAT...LON 3542 8204 3552 8202 3554 8164 3532 8167
TIME...MOT...LOC 2055Z 276DEG 27KT 3546 8194

08