Severe Thunderstorm Warning 150, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
810 PM EDT Mon Jul 22 2019

.SYNOPSIS...
A cold front will approach the region from the northwest tonight
and move slowly across the forecast area on Tuesday. In the front's
wake, high pressure will spread cooler and drier air over the region.
Below normal temperatures and low precipitation chances are expected
from Wednesday through the end of the week.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 745 PM: The hydrologic threat is increasing along and north of
the Interstate 40 corridor in western North Carolina this evening.
Late day thunderstorms have produced some local 1 to 2 inch rainfall
amounts, and this heavier rain has fallen on many locations with 3-
hour flash flood guidance values in the 2 to 3 inch range.
Additionally, the 18Z runs of the numerical models as well as the
near-term mesoscale, convection-allowing models, are depicting
additional rounds of heavier rainfall focusing on western North
Carolina through the nighttime and Tuesday morning hours. It seemed
prudent to expand the Flash Flood Watch out along the I-40 corridor
into western NC through Tuesday morning.

Otherwise, the general setup persists, with an upper trough digging
from the Great Lakes this evening to the spine of the Appalachians
on Tuesday, with substantial height falls occurring across the
forecast area. As the trough deepens, an upper jetlet will
strengthen on the southeast side, producing strong upper divergence
over our forecast area during the 06Z to 18Z time frame Tuesday.
With this forcing, plenty of moisture will be available as PWATs
over 2" are expected in the unidirectional deep-layer SWLY flow
overnight. At the sfc, a cold front will sag slowly SEWD from the OH
and TN valleys, crossing the mountains late tonight/early Tuesday
morning, then pushing into the Piedmont by midday. All these
ingredients will set up the aforementioned heavy rain/flash flood
threat. Also, with the convection, there will a marginal damaging
wind threat, with any of the strongest storms. There may also be
some quasi-organization of convection this evening as the front gets
close to the TN border. Lows tonight will be mainly in the 60s
mountains and lower 70s piedmont.

Later on Tuesday, the front and forcing will gradually shift east of
the area, bringing the better rain rates with it. There could be
some spotty excessive rain across the I-85 corridor late morning
thru mid-aftn, but confidence is still not enough to warrant
expanding the Flash Flood Watch down into the Charlotte Metro Area.
There is some uncertainty on how much CAPE will be available to keep
the better rain rates going, and flash flood guidance are overall
higher farther south. But in the very least, categorical coverage of
precip looks like a good bet. Temps will be held below normal, given
the clouds and precip with the fropa.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 130 PM EDT Monday: The short term will be marked by a rare
July frontal passage early Wednesday morning, with most guidance
agreeing now that the wind shift and moisture gradient will pass
through most of the area by 12Z Wednesday. The daytime Wednesday
will be a rare treat for mid-summer in the south, with temperatures
5 or more degrees below average, dew points in the high 50s to near
60, and mostly clear skies as a cool and dry Canadian surface high
pressure system moves in. Thursday will look quite similar, with no
moisture return expected and only a modest rise in heights as the
upper trough axis lifts towards the NE, allowing max temps to warm a
degree of two.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 130 PM EDT Monday: The medium range continues as an extension
of the short term forecast, with drier and slightly cooler than
average conditions expected Friday and into the weekend.
Temperatures will moderate towards normal by Sunday/Monday as
heights rise aloft, but with our area wedged between two large upper
anticyclones and the westerlies streaming by to our north, little
moisture return is expected in our area until early next week.

This upper pattern will begin to break down by early next week,
allowing dew points to rise again with a gradual return of diurnal
convection (favoring the higher terrain) Monday and Tuesday.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: The very moist airmass in place over the
terminal forecast area in advance of an approaching upper trough and
unseasonably strong cold front will make the placement and timing of
precipitation quite difficult through the period. The general
approach will be to focus TEMPO thunder chances this evening with
the peak diurnal instability, and then PROB thunder chances on
Tuesday just ahead of the main cold frontal passage. Intervals in
between may be filled with mainly SHRA and occasional VCTS.
Anticipate cigs and vsby settling down into the MVFR range toward
daybreak from the west as the better moisture moves in. Cannot rule
out some IFR at times as well in the heaviest downpours, with KAVL
seeing the best IFR chance through the morning hours. Southwest
winds will toggle quickly northwest with fropa Tuesday afternoon and
then turn northeasterly through late day with low clouds and light
rainfall possibly persisting through sundown.

Outlook: An unseasonably strong cold front will push southeast of
the Tuesday night. This will bring unusually dry and quiet weather
for late July across the region for the rest of the week. VFR
conditions are expected to prevail within a dry Canadian airmass.

Confidence Table...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       High 100%     High 100%     Med   73%     Med   70%
KGSP       High 100%     High  99%     Med   73%     High  97%
KAVL       High 100%     Med   74%     Med   68%     High  99%
KHKY       High 100%     High  85%     Med   69%     High  86%
KGMU       High 100%     High  99%     Med   77%     High  97%
KAND       High 100%     High 100%     High  87%     High  94%

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...Flash Flood Watch through Tuesday morning for NCZ033-035>037-
     048>053-056-058-059-501>506.
SC...None.

&&

SYNOPSIS...JPT
NEAR TERM...ARK/HG
SHORT TERM...Carroll
LONG TERM...Carroll
AVIATION...ARK/HG

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
648 PM EDT Mon Jul 22 2019

GAZ010-017-018-026-028-029-NCZ057-062>065-068>072-082-507>510-
SCZ001>014-019-232300-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Rowan-Macon-
Southern Jackson-Transylvania-Henderson-Cleveland-Lincoln-Gaston-
Mecklenburg-Cabarrus-Union-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-
648 PM EDT Mon Jul 22 2019

This Hazardous Weather Outlook is for northeast Georgia, the southern
mountains, foothills, and Piedmont of western North Carolina, and
Upstate South Carolina.

.DAY ONE...Tonight.

Scattered to numerous showers and thunderstorms will continue to
develop and move east across the area through the night. A few of
the thunderstorms may become severe, primarily this evening, with
damaging wind gusts the main threat. Isolated flash flooding from
heavy rainfall will also be possible through the nighttime hours. Any
of these thunderstorms may contain frequent lightning as well.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Showers and thunderstorms will continue through Tuesday afternoon
as a cold front moves over the area. Isolated flooding will remain
a threat throughout the day.

.SPOTTER INFORMATION STATEMENT...

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

NCZ033-035>037-048>053-056-058-059-501>506-232300-
Avery-Alexander-Iredell-Davie-Madison-Yancey-Mitchell-Swain-Haywood-
Buncombe-Catawba-Graham-Northern Jackson-Caldwell Mountains-
Greater Caldwell-Burke Mountains-Greater Burke-McDowell Mountains-
Eastern McDowell-
648 PM EDT Mon Jul 22 2019

...FLASH FLOOD WATCH IN EFFECT THROUGH TUESDAY MORNING...

This Hazardous Weather Outlook is for much of the North Carolina
mountains, as well as foothill and northwest piedmont locations along
and north of the Interstate 40 corridor in western North Carolina.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

Numerous showers and thunderstorms will continue to develop and move
eastward across region. A few of the thunderstorms may become severe
with damaging wind gusts being the main threat. Any of the
thunderstorms that develop could produce heavy downpours and frequent
lightning.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

Showers and thunderstorms will continue through much of Tuesday as a
cold front moves east through the area. Flooding could remain a
threat into the afternoon.

.SPOTTER INFORMATION STATEMENT...

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

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
827 PM EDT Mon Jul 22 2019

SCZ007-230100-
Spartanburg SC-
827 PM EDT Mon Jul 22 2019

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN SPARTANBURG COUNTY
UNTIL 900 PM EDT...

At 827 PM EDT, Doppler radar was tracking a strong thunderstorm 13
miles south of Columbus, or near Inman, moving northeast at 25 mph.

Locations to be impacted include...
Inman, Lake Bowen, Campobello, Lyman, Greer and Fingerville.

Wind gusts up to 45 mph will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Lake Bowen 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 3491 8219 3501 8222 3504 8222 3519 8207
      3518 8187 3517 8187
TIME...MOT...LOC 0027Z 226DEG 21KT 3505 8215

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
831 PM EDT Mon Jul 22 2019

NCZ070-071-SCZ009-230100-
Gaston NC-Mecklenburg NC-York SC-
831 PM EDT Mon Jul 22 2019

...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL MECKLENBURG...
SOUTHEASTERN GASTON AND NORTH CENTRAL YORK COUNTIES UNTIL 900 PM
EDT...

At 830 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles south of Gastonia, or near Clover, moving northeast at 30 mph.

Locations to be impacted include...
Gastonia, Mt Holly, Belmont, South Gastonia, Clover, Cramerton,
Lowell, Mcadenville, Steele Creek, Lake Wylie and Charlotte Douglas
Airport.

Wind gusts up to 45 mph will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Lake Wylie 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 3507 8122 3516 8130 3533 8104 3517 8092
TIME...MOT...LOC 0030Z 234DEG 25KT 3515 8119

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
833 PM EDT Mon Jul 22 2019

SCZ014-230100-
Chester SC-
833 PM EDT Mon Jul 22 2019

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN CHESTER COUNTY
UNTIL 900 PM EDT...

At 832 PM EDT, Doppler radar was tracking a strong thunderstorm 12
miles southeast of Chester, or near Blackstock, moving northeast at
25 mph.

Locations to be impacted include...
Great Falls, Richburg, Blackstock, Fishing Creek Reservoir and
Cornwell.

Wind gusts up to 40 mph will be possible in these areas.

LAT...LON 3454 8094 3456 8121 3456 8122 3476 8108
      3467 8089 3465 8089 3463 8090 3462 8089
      3460 8089 3459 8088
TIME...MOT...LOC 0032Z 216DEG 20KT 3456 8109

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
908 PM EDT Mon Jul 22 2019

NCZ071-072-230145-
Cabarrus NC-Mecklenburg NC-
908 PM EDT Mon Jul 22 2019

...A STRONG THUNDERSTORM WILL IMPACT CABARRUS AND CENTRAL MECKLENBURG
COUNTIES UNTIL 945 PM EDT...

At 907 PM EDT, Doppler radar was tracking a strong thunderstorm 6
miles north of Uptown Charlotte, moving northeast at 35 mph.

Locations to be impacted include...
Kannapolis, Uptown Charlotte, Huntersville, Northeast Charlotte,
Northwest Charlotte, Concord, Harrisburg, University City and Reedy
Creek Park.

Wind gusts up to 45 mph will be possible in these areas.

LAT...LON 3521 8093 3534 8097 3536 8092 3537 8092
      3551 8066 3550 8046 3532 8045
TIME...MOT...LOC 0107Z 241DEG 29KT 3532 8084

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
910 PM EDT Mon Jul 22 2019

NCZ068-508-SCZ008-230200-
Greater Rutherford NC-Cleveland NC-Cherokee SC-
910 PM EDT Mon Jul 22 2019

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN RUTHERFORD...
SOUTHERN CLEVELAND AND NORTHWESTERN CHEROKEE COUNTIES UNTIL 1000 PM
EDT...

At 910 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles south of Forest City, or near Cowpens National Battlefield,
moving northeast at 35 mph.

Locations to be impacted include...
Shelby, Boiling Springs NC, Lawndale, Patterson Springs, Lattimore,
Mooresboro, Cowpens National Battlefield, Kingstown, Fallston and
Cliffside.

Wind gusts up to 45 mph will be possible in these areas.

LAT...LON 3545 8152 3526 8140 3511 8183 3512 8184
      3518 8187 3519 8191 3520 8190
TIME...MOT...LOC 0110Z 236DEG 29KT 3519 8182

LANE

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
935 PM EDT Mon Jul 22 2019

NCZ082-230200-
Union NC-
935 PM EDT Mon Jul 22 2019

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN UNION COUNTY UNTIL
1000 PM EDT...

At 935 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles northeast of Lancaster, or 4 miles north of Buford, moving
northeast at 25 mph.

Locations to be impacted include...
Monroe, Wingate, Sturdivants, Marshville, Unionville and Trinity.

Wind gusts up to 45 mph will be possible in these areas.

LAT...LON 3486 8032 3481 8040 3482 8071 3483 8072
      3509 8048 3492 8031
TIME...MOT...LOC 0135Z 231DEG 20KT 3483 8062

LANE