Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
252 PM EDT Fri Jul 6 2018

.SYNOPSIS...
A cold front will cross the region this afternoon and evening
bringing widespread showers and thunderstorms with it. In its
wake, cooler and drier air will move over the area through the
weekend. Mostly dry conditions will persist into next week with
a warming trend expected.

&&

.NEAR TERM /THROUGH SATURDAY/...
Scattered to numerous convection that fired across the high terrain
continues to ooze slowly into the foothills this afternoon, with
more movement noted in activity associated with outflow-reinforced
frontal zone that has slipped into the area from the north. All of
this activity will continue to move steadily S/SE, pushed along by
the front and/or cold pools. Likely pops are carried across much of
the area into early evening.

SBCAPE currently ranges from 2500-3500 J/kg, while shear remains
weak. However, DCAPE values of 750 to 1000 J/kg and high Surface
Delta Theta-E values will support continued potential for
microbursts from pulse single cells. Also, shear over cold
pool-depth should be just enough to support continued cell
clustering, enhancing the downburst threat. In addition to the
severe potential, PWATs that are in the 90th percentile of
climatology (around 1.75" at KFFC at 12Z) along with deliberate cell
movement and some training potential will yield a locally excessive
rainfall threat.

A moist easterly flow developing north of the boundary tonight will
support continued chances for showers through much of the 1st
period, especially along the eastern escarpment of the Blue Ridge.
Min temps will settle close to climatology.

As expansive/anomalously high pressure expands from the Great Lakes
into the Northeast and northern Mid-Atlantic late tonight through
tomorrow, resultant ageostrophic adjustment/cold air damming will
become established east of the Appalachians, with a combination of
CAD and persistent low cloud cover expected to result in max temps
about 10 degrees below climo, which would be out coolest day around
here in about 4 weeks. The air mass will therefore be much more
stable on Saturday, except perhaps around the southern and western
periphery of the forecast area, where the highest pops will exist
during the afternoon. Otherwise, pops will gradually increase
through the day, as drier air gradually filters in from the NE.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 230 PM EDT Friday: The ridging aloft which earlier retrograded
back to the western half of the CONUS, gradually will be shifting to
the east once again. Meanwhile surface high pressure from the New
England state wedges down into part of our forecast area (FA).

As drier air seeps into the region Saturday night and Sunday, we
should see a reduction of shower and thunderstorm activity (from
north to south) as high pressure at the surface and aloft become
dominant. It may be a bit of a slower process since moisture and
some instability are maintained. Overall however the trend should be
for less coverage or ending.

The two areas by later Sunday which we will still be carrying some
low end POPS is in our southern lakelands area and and parts of our
southwest NC mountains. At these locations the full wedge type
configuration does not become established, and therefore those
places remain rather moist and unstable, even though they will be
north of the surface front.

We dialed up similar POPS on Monday in the NC mountains, otherwise
we have kept it dry for the remainder of the FA. Otherwise, we will
be watching the tropics closely the next few days for situational
awareness.

In the temperature department, as ridging aloft builds back into the
region we will note temperatures creeping upward each day. Once
again the model signals are nearly the same and we plan to follow.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 210 PM EDT Friday: The extended fcst picks up at 00z on Tues
with steep upper ridging in place over the Western CONUS and broad
upper trofing over Eastern Canada. As we move into Wed, the upper
trof amplifies over New England and pushes the upper ridge farther
to the west. By Thurs, the trof axis begins to move off the Atlantic
Coast as the ridge tries to spread eastward. At the sfc, broad and
weakening high pressure will be lingering over the region to start
the period. In addition, a sub-tropical coastal low is expected to
be just off the Southeast Coast and nearly stationary. The larger
scale synoptic pattern is not expected to change significantly thru
the period, with broad and fairly weak high pressure persisting
over the region. The latest guidance has the above mentioned sfc
low gradually lifting NE and farther offshore as the period wears
on. Thus, it should not have a substantial impact on our sensible
weather. As for the sensible fcst, I kept a mostly diurnal PoP trend
for showers and thunderstorms each afternoon/evening. Temperatures
are expected to remain above normal and warm thru the period. They
should level off by Day 7 on Friday.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: convection is becoming fairly widespread
across the mtns and NC foothills this afternoon, and activity will
continue to roll S and SE into the the Piedmont/Upstate SC
throughout the afternoon and into the evening. Tempos for TSRA are
warranted at all terminals during this time. VCTS/VCSH linger
through about mid-evening, but chances for showers/possible TSRA
will linger well into the overnight, as a cold front sags south
across the area. Winds will become light N/NW by evening in the wake
of this front, then gradually turning toward the NE overnight into
Sat morning and increasing to 10-15 kts at most locales by
mid-morning. Moist E/NE flow north of the front will likely result
in development and expansion of low clouds around sunrise, with
IFR/low MVFR cigs advertised at most terminals.

Outlook: Cigs restrictions and showers may persist into Saturday
afternoon as the frontal boundary settles south of the region.
Unsettled conditions could linger through early next week in the
vicinity of the stalled or dissipating front.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High 100%     High 100%     Med   78%     High  80%
KGSP       High 100%     High 100%     High  88%     High  98%
KAVL       High 100%     High 100%     High  87%     High  90%
KHKY       High 100%     High  98%     High  84%     High  93%
KGMU       High 100%     High 100%     High  89%     High  94%
KAND       High 100%     High 100%     High  94%     High  87%

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...JPT
NEAR TERM...JDL
SHORT TERM...TS
LONG TERM...JPT
AVIATION...JDL

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
540 AM EDT Fri Jul 6 2018

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-070945-
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-
540 AM EDT Fri Jul 6 2018

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

.DAY ONE...Today and Tonight.

Scattered thunderstorms today and tonight will produce cloud-to-
ground lightning and locally heavy rainfall. Stronger storms could
produce localized flooding and gusty winds.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

..Saturday...No hazardous weather is expected at this time.
..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.

.SPOTTER INFORMATION STATEMENT...

None.

SGL

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
247 PM EDT FRI JUL 6 2018

NCZ036-061915-
Iredell NC-
247 PM EDT FRI JUL 6 2018

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL IREDELL COUNTY
UNTIL 315 PM EDT...

At 247 PM EDT, Doppler radar was tracking a strong thunderstorm near
Statesville, moving south at 5 mph.

Locations to be impacted include...
Statesville and Troutman.

Wind gusts up to 45 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.

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 3576 8074 3571 8076 3571 8090 3587 8089
      3588 8079
TIME...MOT...LOC 1847Z 353DEG 5KT 3581 8082

08

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
254 PM EDT FRI JUL 6 2018

SCZ006-061930-
Greater Greenville SC-
254 PM EDT FRI JUL 6 2018

...STRONG THUNDERSTORMS WILL IMPACT EAST CENTRAL GREENVILLE COUNTY
UNTIL 330 PM EDT...

At 254 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 15 miles northeast of Easley to 3 miles west of
Downtown Greenville, and moving south at 5 mph.

Locations to be impacted include... Greenville, Taylors, Berea,
Welcome, Cherrydale Point, Piedmont, Paris Mountain State Park and
Donaldson Center.

Wind gusts up to 45 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.

These storms 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 3472 8247 3478 8245 3478 8246 3479 8246
      3481 8248 3488 8248 3499 8231 3484 8223
      3471 8246
TIME...MOT...LOC 1854Z 359DEG 6KT 3492 8235 3484 8246

08

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
320 PM EDT FRI JUL 6 2018

NCZ071-072-062000-
Mecklenburg NC-Cabarrus NC-
320 PM EDT FRI JUL 6 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN CABARRUS AND
SOUTHEASTERN MECKLENBURG COUNTIES UNTIL 400 PM EDT...

At 320 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles east of Uptown Charlotte, or near Reedy Creek Park, moving west
at 5 mph.

Locations to be impacted include... Concord, Northeast Charlotte,
Matthews, Mint Hill, Harrisburg, Reedy Creek Park, The Plaza and
Charlotte Motor Speedway.

Wind gusts up to 45 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour 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.

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

&&

LAT...LON 3541 8060 3524 8050 3509 8075 3537 8086
TIME...MOT...LOC 1920Z 067DEG 5KT 3527 8067

08

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
326 PM EDT FRI JUL 6 2018

NCZ033-036-056-057-068>072-501>506-508-062030-
Rowan NC-Caldwell Mountains NC-Iredell NC-Cleveland NC-Lincoln NC-
Greater Burke NC-Eastern McDowell NC-Avery NC-Greater Rutherford NC-
McDowell Mountains NC-Gaston NC-Burke Mountains NC-
Greater Caldwell NC-Mecklenburg NC-Cabarrus NC-Catawba NC-
326 PM EDT FRI JUL 6 2018

...A CLUSTER OF THUNDERSTORMS WITH INTENSE LIGHTNING WILL IMPACT
CATAWBA...NORTHEASTERN RUTHERFORD...LINCOLN...NORTHERN GASTON...
CABARRUS...EASTERN MCDOWELL...SOUTHERN IREDELL...SOUTHERN CALDWELL...
SOUTHEASTERN AVERY...NORTHWESTERN MECKLENBURG...ROWAN...NORTHWESTERN
CLEVELAND AND BURKE COUNTIES UNTIL 430 PM EDT...

At 325 PM EDT, Doppler radar indicated the leading edge of a cluster
of thunderstorms with intense lightning along a line extending from 7
miles west of Lexington to 4 miles south of Statesville to 6 miles
southeast of Lenoir to 4 miles south of Newland, and moving south at
25 mph.

Locations to be impacted include... Huntersville, Kannapolis,
Hickory, Concord, Salisbury, Morganton, Newton, Lincolnton, Marion
and Lenoir.

In addition to intense lightning, wind gusts up to 40 mph, pea size
hail and very heavy rainfall rates up to 2 inches per hour 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.

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

Frequent lightning is occurring with these storms. 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 storms approach.

These storms 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 3550 8030 3539 8037 3529 8088 3541 8147
      3565 8203 3606 8195 3585 8148 3582 8134
      3580 8133 3581 8126 3574 8088 3580 8056
      3578 8051 3578 8048 3573 8045 3571 8033
      3568 8033 3563 8027 3550 8025
TIME...MOT...LOC 1925Z 357DEG 22KT 3580 8040 3571 8088 3583 8148 3601
8193

08

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
328 PM EDT FRI JUL 6 2018

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

0235 PM     TSTM WND DMG     2 NNW LENOIR            35.93N 81.54W
07/06/2018                   CALDWELL           NC   AMATEUR RADIO

            TREE DOWN ON TELEPHONE CABLE ALONG CREEKWAY DRIVE AND OLD
            HWY 90

&&

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
421 PM EDT FRI JUL 6 2018

NCZ070-071-082-SCZ009-062100-
Gaston NC-Union NC-Mecklenburg NC-York SC-
421 PM EDT FRI JUL 6 2018

...STRONG THUNDERSTORMS WILL IMPACT MECKLENBURG...EASTERN GASTON...
SOUTHWESTERN UNION AND NORTHEASTERN YORK COUNTIES UNTIL 500 PM EDT...

At 420 PM EDT, Doppler radar indicated a cluster of strong
thunderstorms along a line extending from 10 miles southwest of
Huntersville to 6 miles north of Uptown Charlotte to 11 miles
northwest of Monroe, and moving south at 15 mph.

Locations to be impacted include... Charlotte, Huntersville,
Gastonia, and Rock Hill.

Wind gusts up to 45 mph, pea size hail and torrential rainfall rates
up to 3 inches per hour 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. Power outages may
result.

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

These storms 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 3482 8074 3482 8080 3494 8078 3508 8091
      3503 8090 3501 8091 3499 8089 3492 8086
      3488 8088 3494 8096 3510 8126 3541 8108
      3540 8096 3541 8096 3539 8081 3507 8066
TIME...MOT...LOC 2020Z 020DEG 14KT 3533 8100 3531 8083 3508 8072

08