Severe Thunderstorm Warning 31, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
251 PM EDT Thu May 10 2018

.SYNOPSIS...
Showers and thunderstorms continue through this evening as a cold
front crosses the area. Mainly mountain afternoon and evening
thunderstorms are expected Friday and Saturday. Temperatures will
increase to near record levels by Sunday then slowly cool through
next week. Precipitation chances gradually increase through next
week as a complex low pressure system impacts the area.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 225 PM: The latest convection-allow models have a band of
broken convection filling in rather quickly over the southern
Appalachians and adjacent foothills through 19Z. This is consistent
with the timing of a shortwave crossing the region aloft, and radar
trends are headed in that direction with stronger convection
starting to perk. Given model thermal profiles and morning raobs
exhibiting freezing levels in the 11.5 to 12.0 kft range across the
region, hail could become a factor with any 55+ dbZ cores touching
23 kft, or lower-level, higher reflectivity 60 to 65 dBZ cores in
the 17 to 20 kft range. We are still anticipating some wind
potential, with modest sfc to mid-level theta e lapses around 20K
this afternoon, but with a developing DCAPE pool near 1000 J/kg over
the southern tier and around the Charlotte area late day. The best
developing convective cold pool gusts should be across piedmont
areas around I-77 late this afternoon into the early evening, with a
secondary maximum over the southwest NC mountains this afternoon.

The main convection should exit east of the area by 00Z. Isolated
showers may continue to arrive in the northwest flow across the
southwest mountains through midnight before dissipating. Locations
receiving heavy rain this afternoon/evening, as well as the mountain
river valleys, could well see fog and low clouds toward daybreak
Friday. Mild mins should run 5 to 10 degrees above climo.

Flat mid-upper ridging will develop over the southeast on Friday,
but a very weak H5 trough embedded in the ridge could provide weak
afternoon forcing over the NC mountains. A weak lee trough should
develop just east of the Blue Ridge as well to toggle winds back
toward southwesterly. Anticipate max temps warming at least a couple
of degrees above Thursday values, with isolated to scattered diurnal
convection focused mainly along the eastern slopes of the
mountains.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 215 PM EDT Thursday: Weak upper shortwave will be passing
across the area, embedded in the flow atop the Gulf/Caribbean upper
ridge, at the beginning of the period. Any lingering convection from
Friday night should dissipate quickly on the back side of the wave.
For Saturday afternoon, continued mid-level warming with the upper
ridge in place and a weak surface trough in place should continue
the low-level WAA, resulting in afternoon highs a couple of degrees
warmer than what we'll see on Friday, with just about everywhere
across the Piedmont progged to reach the 90-degree mark. Without
upper support, convection will be limited to just the airmass
instability and mechanical lift from the mountains, so have dropped
most of the pops from the Piedmont. Thicknesses will increase
further still on Sunday as a broad upper trough remains in place
over E Canada and ridging amplifies over the center of the country.
The big story here will be the record-level highs; currently have a
record forecast for CLT, which will break a record that has been in
place for 137 years! Luckily dewpoints won't be ridiculous, so, so
far, no real concerns with heat indices. Very little change in low
temps through the period (actually, through the extended,
too...maybe fluctuating by 5 degrees through the end of next week).
Mid-level warming/subsidence will continue to increase, and this
will significantly limit convective potential even over the
mountains, with only some pockets of slight chance pops forecast at
this time.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 230 PM EDT Thursday: Still no major changes to the extended
from previous forecasts. With the subtropical ridge continuing in
place, Monday should be very similar to Sunday, maybe a degree or
two cooler, and with slightly more convection especially over the
mountains, but cannot rule out isolated activity over the Piedmont
as well.

Things start changing as we move into Tuesday and through the rest
of the period. A tropical weakness in the Gulf will strengthen just
slightly on Sunday, spinning near the FL Big Bend on Monday and
beginning to drift north into the Southeast Monday night and
Tuesday. Increasing cloud cover and precip chances will be expected,
and a corresponding decrease in afternoon highs (still above normal
though). From Tuesday through the end of the period, it looks fairly
wet...though QPF amounts aren't particularly impressive, low-level
moisture will remain high and thus higher pops are warranted, with
the best chances Wednesday afternoon where we have likely pops
painted across the area. Airmass instability will remain but lapse
rates in the tropical environment unimpressive, so some question as
to how much showery vs. thundery activity there will be. A shortwave
trough pushing toward the OH Valley at the end of the period will
slowly absorb the tropical low, but the tropical moisture feed from
the western Caribbean will continue so chance pops remain in the
forecast, with highs remaining 3-5 degrees above normal.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
At KCLT and Elsewhere: There is reasonably good consensus on the
foothills convection developing into a broken line across the NC
piedmont late this afternoon and impacting KCLT mainly from 21Z to
23Z. Reasonably good cold pool winds of 25 to 30 kt should be
expected from the WNW, and gusts could reach quite a bit higher if
the convective strength builds into the stronger piedmont DCAPE
area. Convection should be a bit spottier elsewhere, with KHKY to
KAVL seeing the next best chance, but more scattered activity across
the Upstate terminal area. Will handle with mainly a VCTS in
southern sections. Any restrictions through the evening hours will
be brief MVFR to possibly IFR under the heaviest downpours.

Any locations that receive rain late today will be a candidate for
fog/stratus development toward daybreak Friday. Chances appear best
at KCLT and also in the mountain river valleys. Will remain fairly
conservative for now given the reserved MOS forecasts, but will
definitely hint that way at KCLT with some morning SCT007 along with
MVFR fog. Convective coverage should be quite a bit less on Friday,
with no mention before 18Z throughout, and nothing after 18Z at
KCLT. Winds will toggle back to SW with lee troughing early Friday,
except mainly NW at KAVL.

Outlook: Isolated to scattered diurnal convection will likely return
mainly over the higher terrain on Friday afternoon and into the
weekend. Any restrictions should be confined to areas under
showers/thunderstorms or daybreak fog/stratus in the lower mountain
valleys.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High 100%     High 100%     Low   50%     High  82%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     Med   67%     High  91%
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

&&

.CLIMATE...

RECORDS FOR 05-11

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      89 1889     50 1960     64 1890     30 1966
   KCLT      95 1916     58 1924     70 1889     39 1977
                1896
                1889
   KGSP      96 1889     59 1924     69 1963     33 1906

RECORDS FOR 05-12

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      88 1980     44 1960     65 1918     36 1969
                1956
                1914
   KCLT      94 1889     56 1960     69 1896     39 1969
   KGSP      99 1916     56 1960     68 1979     38 1989
                                        1933
RECORDS FOR 05-13

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      90 1933     54 1917     67 1890     31 1895
   KCLT      93 1881     59 1891     73 1881     38 1960
   KGSP      95 1886     62 1972     71 1933     37 1917
                            1954
                            1938

&&

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

&&

SYNOPSIS...RWH
NEAR TERM...HG
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...HG
CLIMATE...

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
431 PM EDT Thu May 10 2018

GAZ010-017-018-NCZ033-048>053-058-059-062>065-501>506-SCZ001>006-
112045-
Rabun-Habersham-Stephens-Avery-Madison-Yancey-Mitchell-Swain-Haywood-
Buncombe-Graham-Northern Jackson-Macon-Southern Jackson-Transylvania-
Henderson-Caldwell Mountains-Greater Caldwell-Burke Mountains-
Greater Burke-McDowell Mountains-Eastern McDowell-Oconee Mountains-
Pickens Mountains-Greenville Mountains-Greater Oconee-
Greater Pickens-Greater Greenville-
431 PM EDT Thu May 10 2018

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

.DAY ONE...Tonight.

Scattered to numerous thunderstorms are developing ahead of a cold
front approaching from the west this afternoon. Some of the
thunderstorms could become severe over the foothills and especially
the piedmont through early this evening. Cloud-to-ground lighting,
briefly heavy rainfall, and gusty winds can be expected with any of
these storms. Some of the strongest thunderstorms will be capable of
producing quarter-sized hail and damaging wind gusts. The storms
should move away to the east by around sunset.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

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

.SPOTTER INFORMATION STATEMENT...

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

NCZ035>037-056-057-068>072-082-507>510-SCZ007>009-013-014-112045-
Alexander-Iredell-Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-
Mecklenburg-Cabarrus-Union-Rutherford Mountains-Greater Rutherford-
Polk Mountains-Eastern Polk-Spartanburg-Cherokee-York-Chester-
431 PM EDT Thu May 10 2018

...SEVERE THUNDERSTORM WATCH 80 IN EFFECT UNTIL 10 PM EDT THIS
EVENING...

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

   Severe Thunderstorm Watch.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

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

.SPOTTER INFORMATION STATEMENT...

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

GAZ026-028-029-SCZ010>012-019-112045-
Franklin-Hart-Elbert-Anderson-Abbeville-Laurens-Greenwood-
431 PM EDT Thu May 10 2018

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

.DAY ONE...Tonight.

Scattered thunderstorms are developing ahead of a cold front
approaching from the west. Cloud-to-ground lighting, briefly heavy
rainfall, and gusty winds can be expected with any of these storms.
One or two of the thunderstorms may become strong enough to produce
large hail and damaging wind gusts. The storms should move away to
the east by around sunset.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

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

.SPOTTER INFORMATION STATEMENT...

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

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
407 PM EDT THU MAY 10 2018

NCZ051-052-059-062>064-102045-
Transylvania NC-Haywood NC-Swain NC-Southern Jackson NC-
Northern Jackson NC-Macon NC-
407 PM EDT THU MAY 10 2018

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT
NORTHEASTERN MACON...SOUTHWESTERN TRANSYLVANIA...JACKSON...
SOUTHEASTERN SWAIN AND SOUTH CENTRAL HAYWOOD COUNTIES UNTIL 445 PM
EDT...

At 406 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning 5 miles southeast of Bryson City, moving east at 30
mph.

Locations to be impacted include...
Sylva, Bryson City, Cherokee, Cullowhee, Webster, Dillsboro,
Cashiers, Graveyard Fields, Smoky Mountains-Deep Creek and Lake
Glenville.

In addition to intense lightning, wind gusts up to 50 mph and dime
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.

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 3531 8355 3553 8345 3534 8283 3506 8301
TIME...MOT...LOC 2006Z 288DEG 27KT 3537 8338

Carroll

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
412 PM EDT THU MAY 10 2018

NCZ068-503-504-506-508-102045-
Greater Rutherford NC-Burke Mountains NC-Cleveland NC-
Greater Burke NC-Eastern McDowell NC-
412 PM EDT THU MAY 10 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN MCDOWELL...
NORTHEASTERN RUTHERFORD...NORTHWESTERN CLEVELAND AND SOUTHWESTERN
BURKE COUNTIES UNTIL 445 PM EDT...

At 412 PM EDT, Doppler radar was tracking a strong thunderstorm 9
miles southeast of Marion, or 7 miles south of Lake James State Park,
moving east at 25 mph.

Locations to be impacted include...
Morganton, Marion, Drexel, Glen Alpine, Lake James State Park, South
Mountains State Park, Lake James, Valdese, Lake Rhodhiss and Nebo.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3579 8157 3578 8156 3549 8164 3558 8204
      3575 8197 3577 8194 3579 8196 3583 8194
TIME...MOT...LOC 2012Z 282DEG 23KT 3563 8185

Carroll

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
418 PM EDT THU MAY 10 2018

NCZ035-036-102100-
Iredell NC-Alexander NC-
418 PM EDT THU MAY 10 2018

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT ALEXANDER
AND NORTHERN IREDELL COUNTIES UNTIL 500 PM EDT...

At 418 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning near Taylorsville, moving east at 20 mph.

Locations to be impacted include...
Statesville, Taylorsville, Stony Point, Harmony, Love Valley,
Hiddenite, Turnersburg, Olin, Millersville and Ellendale.

In addition to intense lightning, wind gusts up to 50 mph and dime
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.

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 3605 8071 3570 8080 3591 8134 3603 8126
      3604 8119 3603 8117 3604 8113 3603 8107
      3606 8098
TIME...MOT...LOC 2018Z 288DEG 17KT 3592 8115

Carroll

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
428 PM EDT THU MAY 10 2018

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

0408 PM     HAIL             4 NW COOKSVILLE         35.63N 81.52W
05/10/2018  E1.00 INCH       BURKE              NC   PUBLIC

            HAIL AT LEAST THE SIZE OF QUARTERS.

&&

OUTLAW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
429 PM EDT THU MAY 10 2018

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

0415 PM     HAIL             1 N COOKSVILLE          35.61N 81.48W
05/10/2018  E1.00 INCH       CATAWBA            NC   TRAINED SPOTTER

            SPOTTER REPORTED UP TO 1 INCH HAIL NORTH OF COOKSVILLE,
            NC.

&&

JPT

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
436 PM EDT THU MAY 10 2018

GAZ010-017-018-SCZ001-102115-
Rabun GA-Stephens GA-Habersham GA-Oconee Mountains SC-
436 PM EDT THU MAY 10 2018

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN STEPHENS...EAST CENTRAL
HABERSHAM...SOUTHEASTERN RABUN AND WESTERN OCONEE COUNTIES UNTIL 515
PM EDT...

At 436 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles north of Toccoa, or near Tallulah Gorge State Park, moving east
at 20 mph.

Locations to be impacted include...
Walhalla, Toccoa, Westminster, Tallulah Falls, Tallulah Gorge State
Park, Oconee State Park, Lakemont, Mountain Rest, Long Creek and
Turnerville.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3478 8342 3494 8310 3469 8305 3460 8317
      3459 8317 3461 8342
TIME...MOT...LOC 2036Z 271DEG 18KT 3470 8333

Carroll