Severe Thunderstorm Warning 234, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
244 PM EDT Wed Sep 28 2016

.SYNOPSIS...
A stationary front will remain over the Midlands of South Carolina
and the Sandhills of North Carolina through Thursday.
Meanwhile, an upper level low will drop south into the Ohio Valley
and linger there through the end of the week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 230 PM Wednesday: A healthy cumulus field has developed across
the area east of the Blue Ridge. Convective initiation is underway
as well, but better coverage was noted across the SC Midlands. Still
think the fcst will catch up over the wrn Piedmont during mid
afternoon. A prime location might be in the vicinity of the old
differential heating boundary running across the I-85 corridor from
w of Charlotte to the Piedmont Triad. The environment across the
Piedmont is mildly compelling, with sfc-based CAPE in the 2000 to
2500 J/kg range, dCAPE above 800 J/kg, and SR helicity on the order
of 100-150 m2/s2. Cannot rule out the development of a few
supercells over the Piedmont thru late afternoon and the Supercell
Composite Parameter on the SPC mesoanalysis agrees. Probably a good
idea the SLGT risk was backed up into the fcst area to account for
this. Still think the environment looks better to our northeast, but
will have to keep a close eye on storms forming and moving over the
CLT metro area and NW Piedmont.

No major surprises in the new model guidance, with the center of a
large upper low moving slowly down across the Midwest/OH Valley
tonight and then over the Cumberland Plateau on Thursday. The trof
axis remains to our west the entire time, with spokes of vorticity
moving around the circulation. This will have a difficult time
pushing the surface front off to the east. Think most of the
convection will die off in the mid/late evening. Dry air will
attempt to filter in from the SW in the dry slot, which should allow
for some cooler temps in northeast GA and the wrn Upstate. However,
there are indications that low level moisture will remain high
across the wrn Piedmont, which could lead to some dense fog around
daybreak. Confidence way too low for any advisories for now.

On Thursday, the upper low is close enough to the mtns such that
more than one fairly strong short wave will pass overhead, along
with some upper divergence. Meanwhile, colder air aloft should
provide some buoyancy. Expect some low-topped convection to develop
in the afternoon over the mtns, so a chance probability will be kept
there. Meanwhile, will also hold onto a chance east of I-77 where
the surface boundary will remain. What is interesting is the
lingering severe storm potential seen on the new Day 2 Outlook. The
drier air filtering in from the SW should keep the convection at bay
over northeast GA and most of Upstate SC. Will bump up high temps a
few degrees for Thursday afternoon on general principles.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 150 PM Wed: Deep upper low remains centered over Kentucky
Thursday night into Friday, then gradually wobbles northward
through Saturday. Heights aloft will have already bottomed out
over our area during this period; upper lapse rates become quite
poor by daytime Friday. Though small precip chances linger over
the northern portion of our CWFA thru Fri mrng, the whole area
is left dry thereafter, with light southerly return flow around
Atlantic high pressure. Mins are expected to be around normal,
with max temps a tad above normal due to plentiful sunshine.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 155 PM EDT Wednesday...At the starting point of 00Z Sunday,
the cut off upper low is forecast to be over NE corner of Indiana.
Other than some cloudiness mainly over the NC Mountains, no sensible
weather for our area. The low will begin to move NE for the rest of
the weekend and open up to the upper westerlies as the low fills.
Our region will be under the influence of a high amplitude upper
ridge and surface high pressure. 500MB trough will be crossing the
West Coast Sunday and the Rockies Monday and Tuesday as our ridge
gets pinched east.

According to the 06Z GFS, Tropical system Matthew will be a powerful
hurricane making landfall on the NC coast Wednesday evening. This
track varies a little from day to day as yesterday the GFS had it
just a little farther east. Over the last 2 to 3 days this model has
been consistent in stating their would be some East Coast impact
from this system. The new 12Z GFS now has the track just slightly
farther east and still close enough to the western wall of
circulation for some affects to Outer Banks.  Still the timing for
passage of NC coast still Wed evening. The GFS has the wind from the
east for our area beginning Tuesday around the north end of the
circulation of Matthew.  The ECMWF is much slower with Matthew just
reaching the Bahamas at the end of the week. The end result for us
at this time is we will stay dry except for perhaps a few showers
late Wednesday north of CLT.

Temps a couple categories above normal Sunday through Tuesday then
Max Temps down near normal Wednesday due to passing Matthew.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
At KCLT...cumulus field developing across the Piedmont with bases in
the 025-035 range. This could result in a temporary ceiling close to
the upper end of MVFR, but this will be left out of the TAF in favor
of keeping the TEMPO for thunderstorms. The latest CAM guidance has
thunderstorms developing nearby as early as 19Z and moving through
as late as 23Z, so this will be the time period covered by the
temporary restriction. Could have some lingering shower activity
into the early evening, then convective debris clouds overnight. The
actual cold front, as it were, does not appear to ever move across
the region, or at least there isn't much of a wind shift behind it.
In fact, the guidance has the winds coming back around to a more
southerly direction. The guidance hits the fog hard again in the
pre-dawn hours, with some guidance going down as low as VLIFR. Will
compromise and introduce another MVFR fog restriction starting at
11Z. This could develop earlier and could also be down in the LIFR
or worse range, but those details are left out for now. Any fog
should burn off quickly. New convection could blow up again across
metro CLT by midday Thursday, but this was left out for brevity.

Elsewhere...could be a few showers that develop near the other TAF
sites but coverage should be isolated, thus only a VCSH was
included. Drier air comes in this evening which should be enough to
keep clouds scattered. Over the mtns, looks like a good scenario for
valley fog in the pre-dawn hours, thus KAVL has a good chance to see
an IFR restriction, perhaps VLIFR by sunrise. KHKY has the next best
chance for seeing low stratus/fog based on its proximity to trapped
low level moisture near the front. Dry air is expected to wrap
around the mtns from the SW, so no fog is anticipated at the Upstate
TAF sites. Otherwise, VFR on Thursday after the fog burns off.
Showers are possible by early afternoon over the mtns, but this was
left out of KAVL for brevity.

Outlook: Dry high pressure will build in slowly behind the front
Thursday afternoon, which should bring VFR conditions in most places
through the end of the week, although some instability could lead to
showers over the NC part of the area on Thursday afternoon.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     High 100%     High  88%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High  94%     Med   78%     High  85%
KHKY       High  89%     High  89%     High  83%     High  83%
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...PM
SHORT TERM...Wimberley
LONG TERM...DEO
AVIATION...PM

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
945 AM EDT WED SEP 28 2016

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

0830 AM     FLOOD            6 S DYSON               34.07N 81.94W
09/28/2016                   GREENWOOD          SC   EMERGENCY MNGR

            GREENWOOD COUNTY EMERGENCY MANAGER REPORTED HALFWAY
            SWAMP CREEK STILL OUT OF ITS BANKS SEVERAL HOURS AFTER THE
            END OF HEAVY RAINFALL.  FOUR TO FIVE INCHES OF RAINFALL
            OCCURRED IN A 6-HOUR PERIOD LAST NIGHT.

&&

JMP

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
307 PM EDT WED SEP 28 2016

NCZ036-037-057-281930-
DAVIE NC-ROWAN NC-IREDELL NC-
307 PM EDT WED SEP 28 2016

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT
NORTHWESTERN ROWAN...EAST CENTRAL IREDELL AND SOUTHWESTERN DAVIE
COUNTIES UNTIL 330 PM EDT...

AT 306 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM WITH
INTENSE LIGHTNING 5 MILES EAST OF STATESVILLE...MOVING NORTHEAST AT
25 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
STATESVILLE...COOLEEMEE...COOL SPRINGS AND SHEFFIELD.

IN ADDITION TO INTENSE LIGHTNING...PEA SIZE HAIL AND WIND GUSTS UP TO
40 MPH 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.

&&

LAT...LON 3571 8079 3580 8089 3597 8070 3582 8054
TIME...MOT...LOC 1906Z 228DEG 23KT 3579 8080

CDG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
319 PM EDT WED SEP 28 2016

NCZ501-502-282015-
GREATER CALDWELL NC-CALDWELL MOUNTAINS NC-
319 PM EDT WED SEP 28 2016

...A STRONG THUNDERSTORM WILL IMPACT CALDWELL COUNTY UNTIL 415 PM
EDT...

AT 318 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 10
MILES WEST OF LENOIR...OR 7 MILES NORTHWEST OF GAMEWELL...MOVING
NORTHEAST AT 25 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
LENOIR...GAMEWELL...CEDAR ROCK...PATTERSON...EDGEMONT...GLOBE...
COLLETTSVILLE...KINGS CREEK AND UPTON.

HALF INCH HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE IN THESE
AREAS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT FOR
WESTERN NORTH CAROLINA.

LAT...LON 3610 8152 3610 8150 3609 8147 3609 8145
      3607 8144 3608 8143 3595 8134 3585 8164
      3588 8171 3592 8175 3593 8178 3595 8178
      3595 8180 3596 8181 3600 8178 3612 8160
      3612 8155
TIME...MOT...LOC 1918Z 239DEG 21KT 3593 8171

CDG