Flash Flood Warning 21, NWS Greenville-Spartanburg, SC

574 
WGUS72 KGSP 270614
FFSGSP

Flash Flood Statement
National Weather Service Greenville-Spartanburg SC
214 AM EDT SUN MAY 27 2018

NCC113-270623-
/O.CAN.KGSP.FF.W.0021.000000T0000Z-180527T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Macon NC-
214 AM EDT SUN MAY 27 2018

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN MACON COUNTY IS
CANCELLED...

The heavy rain has moved out of the warned area and flooding is no 
longer expected to pose a threat. Please continue to heed any 
remaining road closures.

LAT...LON 3514 8351 3515 8321 3513 8319 3511 8318
      3510 8315 3508 8315 3507 8317 3506 8317
      3506 8316 3500 8316 3499 8342 3499 8348
      3500 8351 3500 8352 3502 8352 3503 8353

$$

SGL

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1037 PM EDT Sat May 26 2018

.SYNOPSIS...
Very moist conditions will persist over the region through
the holiday weekend as Alberto develops across the Gulf of
Mexico. Tropical moisture will likely affect our area through the
middle of next week, bringing the potential for continued heavy
rainfall and associated flooding to the region. A pattern change
might be in store for late next week.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 1035 PM: Coverage and intensity of convection has waned with
loss of heating. However, showers and isolated thunderstorms are
still ongoing along the southern Blue Ridge escarpment. This is the
result of lingering instability, a moist low level SSW flow, and mid
level flow that's parallel to the escarpment. This is resulting in
additional periods of heavy rainfall from training cells across that
area. Additional flooding is possible into the overnight as long as
this flow persists. The flow is forecast to abate overnight, but
until it does, the threat remains. Elsewhere, only isolated
convection expected which should diminish shortly after midnight. No
significant problems expected from this convection.

Another round of low stratus and patchy fog is likely early Sunday.
Min temps will again be 5-10 degrees above climo.

It's looking increasingly likely that tomorrow will be rather
inactive convectively (at least in comparison with recent days), as
weak/deep layer ridging will be in place. In fact, short term
guidance is in rather good agreement in wrapping more stable/lower
PWAT air into the forecast area (at least across the southeast half
or so) before the deeper moisture associated with Alberto begins
pushing into the area Sunday evening/night. As such, most of the
guidance has little to no qpf response east of the Blue Ridge
tomorrow afternoon. Pops have therefore been trended down ever so
slightly: ranging from 30-40 across much of the Piedmont/foothills,
to 50-60 across the high terrain. Max temps will be very close to
climo.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 230 PM EDT Saturday: At the start of the period the western
Atlantic high pressure system is locked in across our forecast area
(FA). However, conditions will be changing as Alberto makes a move
north/northwest in the Gulf of Mexico. This pushes the western
Atlantic high to the east and south of the CONUS. More importantly
this allows the flow of deep tropical moisture to make a move toward
our region.

There should be an initial band of precipitation, on the outer
fringes of Alberto, making a run toward our FA late Sunday night or
early Monday morning. The timing is critical, with the GFS on the
fast side, and the new European ( just arriving ) now a little
faster. Meanwhile the NAM and Canadian models not bringing the first
slug of rain until around Monday morning or so. No doubt there
should be heavy rain with PW's running in the 1.5 to 2.0 inch range.

We plan to begin ramping up POPS from south to north late Sunday
night into Monday. Moisture will be plentiful with a diffluent
pattern aloft, therefore clusters of showers and thunderstorms will
continue through a good part of Monday. We have noticed a
bifurcation, or fork, developing in the precipitation swath, with
one area shifting to the east by Monday evening, and the start of an
upslope set-up for our western FA:  including the northeast Georgia,
western upstate of SC and the western mountains of NC.

This appears then to be a focus for late Monday night into at least
Tuesday. Very complicated during this period, as transitory issues
begin to work their way into the equation. Precipitable water values
remain elevated right into Tuesday and perhaps beyond. Overall we
may have multiple areas with water issues, shifting around our area.

As far as a potential issuance of a Flash Flood Watch, we have done
extensive coordination with our surrounding offices: CAE, RAH, FFC,
and our National Center (WPC) for details and support. At this point
we would be looking at a late 3rd period / or 4th period / watch...
then going forward in time. We feel we have time for another model
cycle to provide additional details, so timing and placement could
be realized.

Once again this soupy airmass will not allow for a large diurnal
swing in temperatures during this part of the forecast cycle.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 235 PM EDT Saturday: Wetness continues thru the middle of
the week, but relief might be on the way. Our attention will
drawn to the passage of the remnant low of Alberto on Tuesday
night and Wednesday. The 12Z operational runs of the GFS and ECMWF
are in very good agreement with the track of the remnant low, and
maybe about 6 hrs faster than WPC, but on the same course. This
trend suggests an increase in confidence in the overall scenario,
but the details will remain murky as the track so far to the west
might just keep the bands of heavier rain to the west as well. As
the remnant low passes to the west on its northward track Tuesday
night, we should see the low level flow gradually veer around to
a direction more west of south. As a result, the focus for heavier
rain potential will shift from the Blue Ridge Escarpment toward the
Nantahala and Great Smoky Mtns heading into Wednesday. The location
of a deep moisture plume is uncertain and will affect who has the
higher potential for significant rain, while other locations will
have a diminished threat if a dry slot wraps around and into the
region from the SW. For the time being, the entire fcst area will
be kept in the likely category for rainfall, but eventually parts
of the region will probably need a categorical probability, with
the best potential being over the SW part of the fcst area. We
remain in the cyclonic flow aloft around the remnant low as it
lifts N/NE across the OH Valley/Midwest/Gt Lakes thru Thursday,
with an abundance of low level moisture, which suggests keeping
the precip prob in the likely range. An axis of vorticity is shown
moving across the region late Thursday which should be the beginning
of the end for our recent unpleasantness. After this feature moves
through, followed by the main upper trof axis Thursday night, we
should finally, at long last, get a change of air mass to which
we have been looking forward. The late part of the week should see
the development of a NW flow aloft in a relatively high amplitude
upper pattern, between the old upper trof moving off the east
coast and an upper ridge over the Plains. Friday may still be
fairly active over the mtns because of residual moisture in the
TN/OH valley moving in from the NW, but the developing downslope
east of the mtns should keep the precip chances in check east of
the mtns, with a return to a stronger modulation by the diurnal
cycle. On Saturday... gasp...we may even start to dry out as the
model guidance shows the development of an omega block with an
upper low forming over the nrn Mid-Atlantic, keeping us in the
cooler and drier part of that pattern.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Convective coverage is waning with the loss
of heating. KAVL and KHKY are the only sites where convection will
create restriction potential overnight. The bigger concern is the
continued moist southerly low level flow leading to lowering cig
restrictions with MVFR then IFR before daybreak. LIFR looks likely
for the western sites and possible at KCLT. Fog should drop into the
MVFR range but IFR is possible especially at the normally more foggy
locations. Guidance agrees on drier air moving in during the day
Sunday, so restrictions may lift more rapidly than the past couple
of days. However, still keep MVFR cigs in through about 18Z as the
guidance can be too optimistic. May be less convective coverage
Sunday afternoon with ridging building overhead and drier air moving
in. However, guidance is not in agreement. Will keep persistence and
go PROB30 for now. Winds will generally be SE to SW through the
period but variable near storms and outflow boundaries.

Outlook: Tropical moisture will increase into Memorial Day,
increasing the frequency and intensity of SHRA and associated
restrictions through much of next week. Morning stratus/fog are
possible each day, especially following any heavy rainfall the
previous day.

Confidence Table...

            02-08Z        08-14Z        14-20Z        20-00Z
KCLT       High 100%     Med   61%     Med   71%     High 100%
KGSP       High 100%     Low   54%     Med   68%     High 100%
KAVL       High  93%     Med   74%     High  97%     High 100%
KHKY       High 100%     Med   75%     Med   72%     High 100%
KGMU       High 100%     Med   61%     Med   61%     High 100%
KAND       High 100%     Med   64%     Med   78%     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...PM
NEAR TERM...JDL/RWH
SHORT TERM...TS
LONG TERM...PM
AVIATION...RWH

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
448 PM EDT Sat May 26 2018

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-271200-
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-
448 PM EDT Sat May 26 2018

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

.DAY ONE...Tonight.

Showers and thunderstorms will roam the countryside this evening,
before fading after sunset. The primary weather threats include
locally heavy rain and cloud to ground lightning.

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

..Sunday...Heavy rain possible.
..Monday...Heavy rain with flooding possible.
..Tuesday...Heavy rain with flooding possible.
..Wednesday...Heavy rain with flooding possible.
..Thursday...Heavy rain with flooding possible.
..Friday...No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

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

ACS

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
653 PM EDT SAT MAY 26 2018

NCZ068>070-262330-
Gaston NC-Cleveland NC-Lincoln NC-
653 PM EDT SAT MAY 26 2018

...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT CENTRAL
LINCOLN...EAST CENTRAL CLEVELAND AND NORTHWESTERN GASTON COUNTIES
UNTIL 730 PM EDT...

At 653 PM EDT, Doppler radar was tracking a thunderstorm with
torrential rainfall 8 miles west of Lincolnton, or 4 miles north of
Cherryville, moving east at 15 mph.

Locations to be impacted include...
Lincolnton, Cherryville, Dallas, High Shoals, Waco, Boger City, Iron
Station, Crouse and Vale.

Very heavy rainfall rates up to 2 inches per hour will be possible in
these 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 3555 8114 3531 8115 3536 8148 3554 8147
      3556 8130
TIME...MOT...LOC 2253Z 271DEG 11KT 3545 8139

ARK

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
713 PM EDT SAT MAY 26 2018

NCZ037-057-262345-
Rowan NC-Davie NC-
713 PM EDT SAT MAY 26 2018

...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT SOUTHEASTERN
DAVIE AND NORTH CENTRAL ROWAN COUNTIES UNTIL 745 PM EDT...

At 712 PM EDT, Doppler radar was tracking a thunderstorm with
torrential rainfall 8 miles southeast of Mocksville, or 5 miles east
of Cooleemee, moving northeast at 25 mph.

Locations to be impacted include...
Salisbury, Cooleemee, Spencer, Fork Church and Advance.

Wind gusts up to 35 mph will be possible in these 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 3589 8040 3588 8042 3587 8039 3585 8039
      3585 8042 3583 8043 3583 8046 3584 8047
      3583 8049 3581 8047 3579 8048 3577 8045
      3574 8046 3572 8038 3568 8048 3583 8060
      3597 8040 3596 8038 3589 8037
TIME...MOT...LOC 2312Z 236DEG 23KT 3580 8047

ARK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
826 PM EDT SAT MAY 26 2018

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

0825 PM     FLASH FLOOD      BRYSON CITY             35.43N 83.45W
05/26/2018                   SWAIN              NC   911 CALL CENTER

            NUMEROUS ROADS CLOSED AND ROADWAYS FLOODED IN BRYSON CITY
            AND JUST TO THE NORTH OF THE CITY.

&&

LEC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1210 AM EDT SUN MAY 27 2018

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

0825 PM     FLASH FLOOD      BRYSON CITY             35.43N 83.45W
05/26/2018                   SWAIN              NC   EMERGENCY MNGR

            ONE HOME WITH INTERNAL FLOOD DAMAGE. ONE STATE ROAD
            DAMAGED. SEVERAL CITY STREETS WITH MINOR DAMAGE.

&&

RWH