Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
617 PM EDT Fri Aug 4 2017

.SYNOPSIS...
A cold front will cross our area tonight and become stationary from
central Georgia to eastern North Carolina Saturday night. This front
moves north as a warm front Sunday and Sunday night as low pressure
passes from Texas to across the Ohio Valley.  The front will become
stationary again across our region for much of the week with deep
moisture and periods of heavy rain.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 615 pm: Recent runs of the HRRR depict convective coverage
filling in across the NC foothills early this evening and surviving
across the NC piedmont through midnight as the surface cold front
finally arrives in the mountains. PoPs have been adjusted up through
04Z in these areas. The meso analysis and recent mesoscale model
runs are now depicting about 30+ kt of sfc to 6 km shear over the
mountains, with lesser amounts over the foothills, but the
instability remains the limiting factor for severe convection with
most areas around 1000 J/kg of sbCAPE. Any severe tstms should be
rather isolated in nature. We will also need to keep an eye on the
expanding area of showers from the GA piedmont for a possible PoP
increase across the southern tier through late evening and early
overnight as well. PoPs should dwindle from the northwest overnight
and mins will be near to just above climo.

The consensus in model guidance is that the front will generally
settle south of our area (or perhaps over our southern zones)
through the day on Saturday, with drier air filtering through much
of the area on NW flow. However, the moisture gradient across the
boundary will be sufficiently broad such that positive buoyancy is
progged to develop from roughly the NC/SC border south. Diurnal
frontal convection should primarily be focused south of our area,
but a slight chance is nevertheless warranted east of I-85.
Meanwhile, instability should be sufficient to fire some isolated
cells across the southern Blue Ridge, and slight chances will be
carried across the southern mtns as well as the southern NC and SC
foothills. Max temps should again fall just shy of climo.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 215 PM Friday: An upper wave will cross the Central Plains and
into the Mid-MS Valley Saturday night thru Sunday, possibly being
enhanced by an MCS. This wave will then shear out within confluent
quasi-zonal flow over the OH Valley to the Mid-Atlantic Sunday night
thru Monday. At the sfc, a stalled front will lift back north as a
warm front, but will be fairly weak. Guidance has slowed down the
return of moisture atop the front thru the day on Sunday, so PoPs
were tweaked downward, especially across the northern half of the
CWFA. As for severe threat, guidance shows limited overlap of CAPE
and bulk shear. So threat should be low. A wavy front roughly
parallel to the upper level flow will set up across the Mid-South to
the OH Valley. Persistent SWLY flow atop the CWFA on the south side
of this boundary will provide plenty of moisture for convection on
Monday. So will have PoPs ramp up to high-end CHC to likely along
the west-facing slopes. Max temps will be near to slightly below
normal and mins near normal both days.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 155 PM Fri: Beginning Monday evening, the cold front drifts
south into our area from Tennessee then becomes nearly stationary
roughly from west to east across the deep south to the Carolinas.
The front remains this way through the remainder of the forecast.
Precipitable water values will be around 2 inches and at times above
that, especially from Wednesday through Friday. This prolonged
period of high Pwats with a stationary front to focus convection
will result in concerns for potential flooding which will increase
as the ground becomes saturated. A broad 500mb trough remains over
the East with shortwaves rotating SE from the upper Plains states to
our region then NE off the New England coast. This will periodically
enhance rainfall as surface low pressures move along the front over
our area. As a result of the thick cloud cover and periods of rain,
max temperatures are trending downward. Looks like Wednesday may be
the coolest as forecast highs from northeast Georgia to Charlotte
are in the lower 80s and this may be too high given the saturation
of the atmosphere. Overall max temperatures several degrees below
normal and Min temperatures near normal or even slightly above given
the thick clouds. There may also be periods of late night and early
morning fog to deal with as dew points and temperatures match
yielding 100% RH.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: An organized area of convection ahead of a
cold front across East TN will move across the mountains of western
NC through late afternoon, while additional development occurs east
over the foothills. The best chances for convection will be at the
western NC sites, where tempos are warranted beginning as early as
20Z at KAVL, and as late as 23Z at KCLT. These sites may actually
see a couple of distinct periods of convection, and tempos may need
adjustment to account for that at some point. Coverage is expected
to be less across Upstate SC. However, developing activity on the
south side of ATL metro moving northeast could impact these sites by
late afternoon (activity could also roll off the Blue Ridge near
KGMU/KGSP by this time). This warrants inclusion of a VCTS at the
Upstate terminals from late afternoon through early evening.

Convection should gradually diminish this evening, but with the cold
front moving into the area late, cannot completely rule out a few
showers through Saturday morning. Low levels will remain moist
overnight, while mid/upper levels dry out. This will create the
potential for fog and/or low stratus, although much may depend upon
what sites receive rainfall later today. Opted to limit early
Saturday restrictions to KAVL/KHKY for the time being.

Outlook: The cold front is expected to settle south of the terminals
on Saturday, with coverage of diurnal convection expected to be
isolated at best. Moisture returning over the front may permit
convection to return through the late weekend, with conditions
becoming unsettled through the middle of next week. Restrictions
will be possible with any showers or thunderstorms and fog and low
clouds will be possible each morning around daybreak, mainly in the
mtn valleys, but also in areas that receive heavy rainfall the day
before.

Confidence Table...

            22-04Z        04-10Z        10-16Z        16-18Z
KCLT       High 100%     High 100%     High  94%     High 100%
KGSP       High 100%     High 100%     High  86%     High 100%
KAVL       High 100%     High  91%     High  83%     High 100%
KHKY       High  97%     High 100%     Med   75%     High 100%
KGMU       High 100%     High 100%     High  97%     High 100%
KAND       High 100%     High 100%     High  83%     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...HG/JDL
SHORT TERM...ARK
LONG TERM...DEO
AVIATION...HG/JDL

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
429 PM EDT Fri Aug 4 2017

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-052030-
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-
429 PM EDT Fri Aug 4 2017

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

.DAY ONE...Tonight.

Scattered thunderstorms are expected to develop across the area
through this evening. Any of these thunderstorms may produce cloud-
to-ground lightning and heavy rainfall. A few isolated thunderstorms
may become severe, producing damaging wind gusts and hail up to
around one inch in diameter.

.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...

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

ARK

<!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>

<!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>

<!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>

<!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>

<!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>

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
732 PM EDT FRI AUG 4 2017

NCZ035-050015-
Alexander NC-
732 PM EDT FRI AUG 4 2017

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN ALEXANDER COUNTY UNTIL
815 PM EDT...

At 731 PM EDT, Doppler radar was tracking a strong thunderstorm 4
miles south of Boomer, moving east at 20 mph.

Locations to be impacted include...
Taylorsville, Vashti, Ellendale and Hiddenite.

Wind gusts up to 40 mph and pea size hail 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 3599 8100 3596 8100 3591 8102 3593 8134
      3599 8133 3601 8131 3601 8129 3603 8127
      3604 8119 3603 8117 3604 8113 3603 8107
      3605 8103
TIME...MOT...LOC 2331Z 266DEG 16KT 3601 8126

CDG