Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
545 PM EDT Sat May 19 2018

.SYNOPSIS...
A slow moving low pressure system will move away from our
forecast area Sunday, however the atmosphere will remain very moist
for the next few days and keep a rather high chance of showers and
storms each afternoon and evening.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 545 PM EDT: Minor adjustments made to current temperatures to
coincide with latest trends as the rest of the near term forecast
remains on track. A Flash Flood Watch remains in effect for portions
of the area through midnight.

The heavy rain threat continues to become more of a localized issue
as latest radar depicts scattered showers and isolated thunderstorms
moving across the area with rainfall rates that continue to slowly
decrease from what we've seen the past few days. Elsewhere, plenty
of cloud cover will continue to linger across the FA through this
evening, where a few intermittent peaks of sunshine earlier did
allow for temperatures to warm into the lower 80s this afternoon
along and south of the I-85 corridor, cooler elsewhere. With the
gradual downward trend, anticipate overnight lows to dip into the
60s.

Otherwise, an upper trough will continue to lift north and deamplify
as its axis crosses the CWFA this evening. This is a result of the
large subtropical ridge over the North Atlantic ridging westward
into the Southeast U.S. for Sunday. The low-level and mid-level flow
will briefly turn out of the NW in the wake of the trough, then
become very light. Not expecting much change in air mass, but
guidance generally agrees on slightly drier air and less convective
coverage than last couple days. Very weak shear and SBCAPE of 1500-
2000 J/kg should support pulse convection with a non-zero severe
threat. Highs will climb into the 70s mountains and mid 80s piedmont
on Sunday under partly to mostly cloudy skies.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 215 PM EDT Saturday: Subtropical anticyclone remains remains
anchored off the southeast coast through the period, but it does
weaken slightly and slowly drift southward. A weak upper low starts
the period along the Florida panhandle then opens and slowly drifts
northward into the southern Appalachians through the period. This
keeps a south to southwest low level flow across the area. The
guidance shows instability each day, but weak overall as some low to
mid level warming keeps CAPE values on the low side. The guidance
has also trended away from the drying mid levels keeping surface
delta theta-e and DCAPE values in check. The pattern still looks to
be mainly diurnal in nature, but severe chances have diminished.
Heavy rainfall is possible with any thunderstorm and FFG values will
be low so the flood threat will continue, but hopefully not as
widespread as in previous days. Highs a few degrees above normal
Monday fall to near normal for Tuesday. Lows around 10 degrees above
normal drop a couple of degrees.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 235 PM EDT Saturday: Upper ridging builds in from the west
through the period and merges with the subtropical anticyclone off
the southeastern coast. At the surface, high pressure remains over
the area but does become suppressed as a front drops toward the area
and stalls. This keeps a warm and moist airmass over the area
through the period. However, with the upper ridging in place,
instability is relatively weak due to warm mid level temps. Still,
expect mainly diurnal convection through the period. Severe chances
look to be on the low side with the weak instability, shear, and
little in the way of DCAPE. PW values are relatively high, so
isolated heavy rainfall is possible. The wet antecedent conditions
will keep a flood threat in place through the period. Lows remain
nearly steady around 10 degrees above normal while highs remain
nearly steady around 5 to 10 degrees above normal.

The wild card for this period is the potential tropical or sub-
tropical system that develops over or near the SE CONUS by the end
of the period. Guidance has been insistent that something will form
and be near the SE CONUS or our area by Saturday. Of course, it is
way too early to know if this will directly impact our CWFA.
However, given the rainfall our area has recently received, this
type of system could cause significant problems if it directly
impacted our weather. For now, worry more about the near and short
term convective threats, but keep an eye on the forecast for next
weekend.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Very moist air mass still in place is
resulting in low cloud bases in the 1500 to 3500 ft range and
scattered showers developing. As we continue to destabilize, a few
tstms are expected, which warrant tempos and/or vcts mentions. Flow
turns more out of the west tonight, but still expect stratus to
develop again by daybreak with LIFR/IFR cigs possible. On Sunday the
overall flow briefly turns out of the NW and should result in a
little less coverage of convection than last few days. Winds will
persist out of the SW 5-10 kts thru the period, except variable
around outflows of tstms.

Outlook: An unsettled weather pattern will continue thru early next
week with isolated to scattered SHRA and TSRA each day with
restrictions expected.

Confidence Table...

            21-03z        03-09Z        09-15Z        15-18Z
KCLT       High 100%     High  92%     High  85%     Med   77%
KGSP       High 100%     High  90%     Low   47%     High  93%
KAVL       High 100%     Med   68%     Med   76%     High  96%
KHKY       High 100%     High  96%     Low   55%     High  87%
KGMU       High  87%     High 100%     Med   78%     High  93%
KAND       High 100%     High  98%     Med   60%     High  93%

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 until midnight EDT tonight for NCZ033-049-
     050-053-064-065-501>510.
SC...Flash Flood Watch until midnight EDT tonight for SCZ002-003.

&&

SYNOPSIS...SBK
NEAR TERM...ARK/SGL
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
830 AM EDT Sat May 19 2018

GAZ010-017-018-026-028-029-NCZ035>037-048-051-052-056>059-062-063-
068>072-082-SCZ001-004>014-019-201230-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-
Davie-Madison-Swain-Haywood-Catawba-Rowan-Graham-Northern Jackson-
Macon-Southern Jackson-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-
Union-Oconee Mountains-Greater Oconee-Greater Pickens-
Greater Greenville-Spartanburg-Cherokee-York-Anderson-Abbeville-
Laurens-Chester-Greenwood-
830 AM EDT Sat May 19 2018

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

.DAY ONE...Today and Tonight.

Thunderstorms are possible this afternoon that are not expected to
be severe, but brief heavy rain, small hail, and lightning will be
possible. Gusty winds from thunderstorms could blow down a few trees
due to saturated soils.

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

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

.SPOTTER INFORMATION STATEMENT...

None.

NCZ033-049-050-053-064-065-501>510-SCZ002-003-201230-
Avery-Yancey-Mitchell-Buncombe-Transylvania-Henderson-
Caldwell Mountains-Greater Caldwell-Burke Mountains-Greater Burke-
McDowell Mountains-Eastern McDowell-Rutherford Mountains-
Greater Rutherford-Polk Mountains-Eastern Polk-Pickens Mountains-
Greenville Mountains-
830 AM EDT Sat May 19 2018

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

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

.DAY ONE...Today and 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.

Thunderstorms are possible this afternoon that are not expected to be
severe, but brief heavy rain, small hail, and lightning will be
possible. Gusty winds from thunderstorms could blow down a few trees
due to saturated soils.

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

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

.SPOTTER INFORMATION STATEMENT...

None.

ARK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
230 PM EDT SAT MAY 19 2018

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

0100 AM     FLASH FLOOD      GLENWOOD                35.61N 81.98W
05/19/2018                   MCDOWELL           NC   EMERGENCY MNGR

            EMERGENCY MANAGER REPORTS FLOODING CONDITIONS ALONG THE
            SECOND BROAD RIVER SOUTH OF GLENWOOD WHERE THREE
            CAMPGROUNDS WERE EVACUATED OVERNIGHT. SEVERAL DRIVEWAYS
            HAVE BEEN REPORTED WASHED AWAY BY HIGH WATER AROUND
            GLENWOOD.

&&

SKRENTZ

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
337 PM EDT SAT MAY 19 2018

GAZ010-017-018-SCZ001-004-192015-
Rabun GA-Stephens GA-Habersham GA-Greater Oconee SC-
Oconee Mountains SC-
337 PM EDT SAT MAY 19 2018

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN STEPHENS...NORTHEASTERN
HABERSHAM...SOUTH CENTRAL RABUN AND OCONEE COUNTIES UNTIL 415 PM
EDT...

At 334 PM EDT, Doppler radar was tracking a series of heavy rain
producing showers and embedded thunderstorms moving repeatedly over
the area from Turnerville to Walhalla. These showers were producing
rainfall at rates of one-half to one inch per hour and additional
heavy rainfall is likely through 415 PM.

Locations to be impacted include...
Seneca, Walhalla, Toccoa, Westminster, Tallulah Falls, Salem,
Tallulah Gorge State Park, Oconee State Park, Lake Keowee and Long
Creek.

Deep ponding of water will develop in low-lying and poor drainage
areas. Streams may rise to near bankfull.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3474 8343 3494 8297 3476 8289 3474 8290
      3474 8288 3467 8285 3458 8320 3458 8341
TIME...MOT...LOC 1934Z 246DEG 14KT 3471 8321

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
351 PM EDT SAT MAY 19 2018

NCZ048-192015-
Madison NC-
351 PM EDT SAT MAY 19 2018

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN MADISON COUNTY
UNTIL 415 PM EDT...

At 351 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles northeast of Marshall, or 5 miles north of Mars Hill, moving
east at 15 mph.

Locations to be impacted include...
Mars Hill, Wolf Ridge and Faust.

Wind gusts up to 35 mph, half inch hail, and very heavy rainfall
rates up to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

&&

LAT...LON 3597 8261 3595 8257 3598 8251 3596 8250
      3595 8248 3593 8250 3591 8249 3591 8248
      3589 8245 3586 8242 3582 8241 3581 8246
      3580 8247 3580 8267 3598 8266 3599 8261
TIME...MOT...LOC 1951Z 261DEG 13KT 3591 8256

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
411 PM EDT SAT MAY 19 2018

NCZ048-049-192045-
Yancey NC-Madison NC-
411 PM EDT SAT MAY 19 2018

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN MADISON AND WESTERN
YANCEY COUNTIES UNTIL 445 PM EDT...

At 411 PM EDT, Doppler radar was tracking a strong thunderstorm 9
miles northeast of Marshall, or 4 miles north of Mars Hill, moving
east at 10 mph.

Locations to be impacted include...
Mars Hill, Faust, Swiss, Wolf Ridge and Ramseytown.

Wind gusts up to 35 mph, half inch hail and very heavy rainfall
rates of 1 to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

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 3605 8238 3578 8233 3578 8234 3580 8234
      3581 8235 3582 8238 3581 8244 3581 8246
      3580 8247 3580 8252 3579 8255 3579 8263
      3597 8267 3599 8260 3597 8261 3595 8256
      3601 8246 3603 8244
TIME...MOT...LOC 2011Z 260DEG 8KT 3589 8256

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
435 PM EDT SAT MAY 19 2018

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

0434 PM     FLOOD            4 NW MARS HILL          35.86N 82.60W
05/19/2018                   MADISON            NC   COUNTY OFFICIAL

            DEEP STANDING WATER REPORTED ON BEE TREE ROAD.

&&

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
621 PM EDT SAT MAY 19 2018

GAZ017-018-026-192245-
Franklin GA-Stephens GA-Habersham GA-
621 PM EDT SAT MAY 19 2018

...SHOWERS AND THUNDERSTORMS WITH TORRENTIAL RAINFALL WILL IMPACT
NORTHERN FRANKLIN...STEPHENS AND SOUTHERN HABERSHAM COUNTIES UNTIL
645 PM EDT...

At 619 PM EDT, Doppler radar was tracking a series of heavy rain
producing showers and thunderstorms impacting the area from Cornelia
to Eastanolee in northeast Georgia. These showers were producing
rainfall rates of 1 to 1.5 inches per hour and additional rainfall
is likely through 645 PM.

Locations to be impacted include...
Toccoa, Cornelia, Baldwin, Demorest, Mount Airy, Alto, Martin,
Avalon, Gumlog and Raoul.

Torrential rainfall may produce flooding of low-lying and poor
drainage areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3454 8362 3458 8364 3460 8364 3457 8314
      3456 8314 3456 8313 3447 8311 3439 8329
      3440 8338 3443 8338 3446 8340 3448 8347
      3449 8354 3443 8362 3451 8367
TIME...MOT...LOC 2219Z 278DEG 11KT 3452 8350

HG