Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
248 PM EDT Fri Jun 1 2018

.SYNOPSIS...
A moist airmass will persist through the weekend keeping a chance of
showers and thunderstorms in the forecast. A drier and seasonable
air mass will arrive behind a passing cold front early next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 230 pm: The diurnal convective cycle remains slow to get
started this afternoon, probably due to residual thermo and dynamic
effects of the MCS that dissipated across the southern Appalachians
early today (a reservoir of slightly lower dewpoints developed
across the heart of the CWA earlier this afternoon, but it's showing
signs of giving way). In fact, even the cu field is looking very
uninspired in visible satellite imagery early this afternoon.
Nevertheless, CAM guidance continues  to initiate some cells within
weak lee trough across the NC foothills and far western Piedmont
within the next couple of hours. Meanwhile, convection continues to
expand along remnant outflow boundary and just north of robust CAPE
axis across NW Georgia and northern AL. This activity should
continue to push steadily east, and probably reach the Upper
Savannah River Valley during late afternoon. Would expect the high
terrain to eventually get in on the act as well, but CAMs remain
quite stingy with any ridge top development, so the highest pops (50
percent) will be reserved for the SC/GA border areas and the NC
Piedmont.

Deep layer shear will begin increasing from the west this evening,
but for the most part, severe convective mode should be limited to
pulse cells, or perhaps some small-scale multicell clustering. In
terms of any lingering hydro threat, it's looking more and more as
if the better coverage will remain east and south of the areas with
the most dire antecedent conditions, which is certainly good news,
but still cannot completely rule out a risk of localized flash
flooding.

Convection will diminish this evening in typical fashion, although a
low level NW flow developing in the wake of a mid-level short wave
trough could allow for the occasional shower along the Tennessee
border. Min temps will continue to run a few degrees above normal.
With weak subsidence developing downstream of a TN/OH Valley short
wave ridge, along with weak downslope flow, deep convection may
initially have a tough go of it on Saturday. However, forecast
soundings indicate more than ample instability, with little
inhibition. As such, scattered convection should eventually fire
along across the ridge tops and move southeast, warranting 30-50
pops across the mountains, and 20-30 across the Piedmont. max temps
will be similar to today's readings.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 2:35 PM Friday: The first part of this forecast cycle should
feature an end to lingering showers and thunderstorms Saturday
evening. This is a result of the diurnal cycle ending and the first
upper level trough shifting off to the east.

We may have a short period of upper level ridging late Saturday
night into Sunday morning. But that will be short lived as a second
trough digs rapidly (northwesterly flow aloft )into our forecast
area (FA), roughly late Sunday morning into Sunday evening. This
upper level trough will be accompanied by a secondary cold front.

The combination of frontal convergence and a decent lobe of energy
with the system, should tap residual moisture allowing for updrafts
and scattered showers and thunderstorms to develop. CAPES remain
very respectable, between 1000-2000 J/KG, and 0-6km bulk shear is up
at around 30 kts. However, there is a fair amount of inhibition, and
potential warm layer persisting. We have edged the POPS Sunday up
slightly and will watch for later changes in the convective
parameters.

The showers and thunderstorms should wane Sunday evening, with dry
conditions by Monday morning.

We should remain generally under a northwest flow aloft Monday with
dry conditions. The exception might be in our northern NC mountains
with a cool pool, and a combination of lingering moisture. As a
result we will carry a few showers Monday afternoon.

Final note on the shower and thunderstorm potential in this period:
it appears showers and thunderstorms will be moving along, based on
sounding information. However we will monitor any slowing of the
showers and storms which might cause a local flash flood threat.

In the temperature department, the thermal profiles are showing a
nice warm-up Sunday, before the frontal passage. Following into
Monday we should shave at least a few degrees (at least) in
comparison to Sunday.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 200 PM Friday: Much drier air continues to filter across the
region Monday night and Tuesday on both the GFS and ECMWF. The GFS
has surface high pressure centered over the SE States late Tuesday.
A backdoor cool front drops down mid week but timing is different
from GFS and EC. The EC keeps us dry through the late week although
low pressure over north Florida to offshore SC brings some moisture
near piedmont at the end of the week. The GFS now has increasing
moisture late in the week with the backdoor front stalling over our
area Thursday with a shortwave dropping down from NW on Friday with
good coverage of convection to start the weekend. Since this is the
first run with this increased moisture, will hold off and only
increase POPs just a tad. Temps near normal.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: The convective cycle has been slow to get
going across the area this afternoon, and based upon the appearance
of the cumulus field, we're probably still a couple of hours or so
away from seeing any appreciable coverage of showers and storms. I
still think we'll see scattered coverage develop across the
foothills/far western Piedmont by mid-afternoon, which will then
move east to impact locations near KCLT by late afternoon/early
evening. This is the only site that receives a tempo for TSRA. With
less certainty elsewhere, the convective mention is limited to VCTS
from 20Z/21Z into the evening hours. Convection will diminish by
late evening. Occurrence of fog and/or low stratus late tonight/
early Saturday will hinge largely on which, if any sites receive
significant rainfall later today. Since that's not at all clear, no
overnight restrictions are carried attm. SW winds at around 10 kts
are expected through the evening at most sites, becoming light
overnight before shifting to the W/NW tomorrow morning.

Outlook: Scattered afternoon/evening showers and thunderstorms,
along with possible morning fog at a few locations and/or low cigs
are possible each day through Sunday night. Drier high pressure will
build in from the NW Monday, resulting in even less chances for
convection and restrictions thru the middle of next week.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High  96%     High  99%
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

&&

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

&&

SYNOPSIS...DEO
NEAR TERM...JDL
SHORT TERM...TS
LONG TERM...DEO
AVIATION...JDL

Hazardous Weather Outlook...CORRECTED
National Weather Service Greenville-Spartanburg SC
514 AM EDT Fri Jun 1 2018

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-020900-
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-
514 AM EDT Fri Jun 1 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 to numerous thunderstorms are expected across the area this
afternoon and evening. In addition to the continued threat of
localized flash flooding, a few of the storms will be capable of
producing severe weather in the form of damaging downburst winds
and large hail. Frequent cloud to ground lightning will be
possible with any storm.

.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.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
321 PM EDT FRI JUN 1 2018

NCZ502-504-011945-
Greater Burke NC-Greater Caldwell NC-
321 PM EDT FRI JUN 1 2018

...A STRONG THUNDERSTORM WILL IMPACT SOUTHERN CALDWELL AND EAST
CENTRAL BURKE COUNTIES UNTIL 345 PM EDT...

At 320 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles southwest of Lenoir, or near Gamewell, moving east at 25 mph.

Other thunderstorms will develop across the foothills of North
Carolina through the afternoon hours, some of which will probably
become severe.

Locations to be impacted include...
Lenoir, Morganton, Sawmills, Granite Falls, Valdese, Gamewell,
Hudson, Cajah's Mountain, Drexel and Connelly Springs.

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...

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

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 3601 8133 3575 8138 3573 8139 3574 8168
      3590 8172 3594 8166 3601 8151 3602 8134
TIME...MOT...LOC 1920Z 259DEG 24KT 3585 8161

MOORE