Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
603 PM EDT FRI JUL 15 2016

.SYNOPSIS...
A weak front will drop toward the Southern Appalachians today
and then stall across the area through the weekend, enhancing rain
and thunderstorm chances. Another weak front will approach the
region by the middle of next week, keeping the area in an
active summertime pattern of afternoon showers and thunderstorms.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 6 PM: Recent satellite loop indicated a expanding and
developing CU field across the eastern foothills and Piedmont.
Latest radar loop indicated numerous showers and thunderstorms
within the CU field, tracking ENE. I will update the forecast to
indicate likely PoPs east of the the mtns. Several areas have temps
fall during downpours, I will update with the latest sfc analysis to
highlight some of the cool spots.

At 230 PM Friday: A low amplitude upper trough will slowly progress
across the southern Appalachians through Saturday, with a weak
shortwave moving over the mountains overnight. A surface trough will
remain east of the mountains during the same time frame. Deep Gulf
moisture streaming northeast along this trough, combined with modest
instability, will support precipitation production, especially
during daylight hours when instability will be best. Relatively weak
shear will not be especially conducive to organized convection, but
modest steering flow may yield copious rainfall totals, especially
if cells can train across the same areas. Temperatures will run near
normal under the upper trough.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 145 pm EDT Friday:  Upper forcing will linger over the
forecast area through Saturday night as the axis of a broad eastern
CONUS trough lifts through the region. The surface cold front in the
vicinity will gradually wash out as the thermal contrast is lost,
but lingering PoPs will continue, especially in SE sections,
overnight. 500 mb heights will then steadily build from the west on
Sunday with the surface Bermuda high becoming slowly resurgent.
Despite some deeper layer drying, the boundary layer should remain
moist enough for scattered ridgetop convection on Sunday which could
migrate into the foothills on outflows along with daytime heating. A
weak lee trough will persist in the piedmont as well.

595 dm 500 mb heights will ridge over the southern Appalachians by
Monday. Isolated to scattered diurnally driven convection is likely
again on Monday with the greatest coverage in and near the
mountains. Better insolation will return as well, with slightly
hotter temperatures and possibly more robust late day SBCAPE values.
With the upper flow pattern amplifying between the central CONUS
ridge and the East Coast trough by late Monday, we'll have to be
cognizant of midwestern convection that could make a run toward the
southern Appalachians near the end of the period.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 200 PM Friday...The medium range picks up at 00Z Tuesday with
a sprawling upper ridge building over the central plains. During the
day on Tuesday, an upper trough will dig southward into the eastern
side of the ridge. This will allow our area to come under broad
cyclonic flow, with a shortwave approaching and surface boundary
being ushered into the southern Appalachians by northwesterly flow
Tuesday afternoon. The previously mentioned forcings appear to
collide favorably with the peak in diurnal heating, so Tuesday
afternoon/evening looks like the most likely time frame in the
extended period for showers and thunderstorms. Some remnants of the
frontal boundary will stall over our area on Wednesday, and with
another shortwave pivoting around the base of the upper trough on
the east coast, diurnal shower and thunderstorm activity may be
slightly enhanced above climo on Wednesday as well. Guidance
disagrees on exactly how/when the upper ridge will break down, so
went with an ECMWF-heavy eastward expansion of the ridge and drying
influence for our CWA on Thursday and Friday. Given the variability
guidance has shown in max and min temps for the extended period over
the past few days, temps were kept near climo as a compromise.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
At KCLT...Low VFR cigs are supported by model data as clouds increase
this afternoon. Convection will be most likely late this afternoon
and early this evening with the best instability. A guidance blend
supports MVFR vsby around daybreak Saturday, but no cig restrictions.
Another round of convection is expected on Saturday, with the best
support after this TAF issuance. Winds will veer from SE to NW this
afternoon, the northeast this evening, the southeast overnight, and
the southwest Saturday morning, as weak surface system moves across
the area.

Elsewhere...Low VFR cigs are expected to form as cloud cover
increases this afternoon. Convection is possible at all sites this
afternoon with increasing instability, persisting into the evening.
IFR or lower cigs are expected in mountain valleys around dawn,
including at KAVL, while low VFR persists to the east. Daybreak
vsbys are expected to be MVFR at foothill sites, and IFR at KAVL.
Another round of convection is expected on Saturday, but the best
support will be after this TAF package. Winds will veer from SW to
NW this afternoon, then become light and variable overnight. On
Friday winds favor the NW, perhaps veering SW late in the forecast.

Outlook...Fairly typical midsummer weather with PM showers and
thunderstorms expected to continue. A frontal boundary pushing in
this weekend will enhance the daily coverage thereof. Each day, AM
fog and low stratus will be possible in the mountain river valleys
and also in locations that receive heavy rainfall in the preceding
PM.

Confidence Table...

            22-04Z        04-10Z        10-16Z        16-18Z
KCLT       High 100%     High 100%     Med   72%     High 100%
KGSP       High 100%     High 100%     High  83%     High 100%
KAVL       High 100%     High  91%     Med   72%     High 100%
KHKY       High 100%     High 100%     High  83%     High 100%
KGMU       High 100%     High 100%     Med   66%     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...LEV
NEAR TERM...NED
SHORT TERM...HG
LONG TERM...LEV
AVIATION...JAT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
313 PM EDT FRI JUL 15 2016

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-161915-
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-
313 PM EDT FRI JUL 15 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT
NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED TO NUMEROUS THUNDERSTORMS WILL CONTINUE TO DEVELOP
ACROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA LATE THIS
AFTERNOON THROUGH THIS EVENING BEFORE GRADUALLY DISSIPATING
OVERNIGHT. SOME OF THESE THUNDERSTORMS MAY BECOME SEVERE...WITH
DAMAGING WIND GUSTS BEING THE PRIMARY THREAT. ANY HAIL PRODUCED
WILL BE MAINLY LESS THAN QUARTER SIZE. ANY OF THE THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING FREQUENT CLOUD TO GROUND LIGHTNING
AND LOCALLY HEAVY RAINFALL.

.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...OR FLASH FLOODING TO OUR OFFICE.

GERAPETRITIS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
617 PM EDT FRI JUL 15 2016

SCZ014-152245-
CHESTER SC-
617 PM EDT FRI JUL 15 2016

...A CLUSTER OF THUNDERSTORMS WILL IMPACT NORTHWESTERN CHESTER COUNTY
UNTIL 645 PM EDT...

AT 617 PM EDT...DOPPLER RADAR INDICATED THE LEADING EDGE OF A CLUSTER
OF THUNDERSTORMS ALONG A LINE EXTENDING FROM 4 MILES NORTHWEST OF
CHESTER TO 16 MILES EAST OF UNION...AND MOVING EAST AT 15 MPH.

LOCATIONS TO BE IMPACTED INCLUDE...
CHESTER...CHESTER STATE PARK...LOWRYS AND LEEDS.

PEA SIZE HAIL AND WIND GUSTS UP TO 45 MPH WILL BE POSSIBLE IN THESE
AREAS.

LAT...LON 3482 8109 3462 8123 3464 8141 3479 8133
TIME...MOT...LOC 2217Z 253DEG 15KT 3476 8126 3465 8135

LANE

<!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>