Severe Thunderstorm Warning 14, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1045 AM EDT Sun May 1 2022

.SYNOPSIS...
An active weather pattern returns with a series of frontal systems
crossing the area from Sunday through much of the upcoming week.
Expect above normal temperatures and a chance of afternoon and
evening showers and thunderstorms most days.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1040 AM EDT Sunday: A few showers developed over the NC
mountains and NW Upstate this morning. Those have diminished. Low
clouds also formed over these areas and will scatter out and lift
but mostly cloudy skies will linger with pops of sun. Showers and
isolated storms will brush the TN border counties through the rest
of the morning ahead of a front extending from an occluding cyclone
over the upper Midwest. Although persistent mid-level moisture will
continue to produce partly to mostly cloud skies over our area
throughout the day, sufficient insolation is expected to allow temps
to warm into the 80s across much of the Piedmont, while dewpoints
remain in the lower 60s. Meanwhile, the forecast area finds itself
on the periphery of the elevated mixed layer, with mid-level lapse
rates expected to run around 7 C/km through the period, confirmed by
the 12Z RAOBs. The environment is therefore expected to destabilize
to the tune of ~2000 J/kg of sbCAPE across much of the area as the
front and associated short wave trough begin impacting the region.
Despite this, the atmosphere is not expected to be especially well-
forced, and a consensus of CAMs guidance suggests coverage will
remain somewhat scattered east of the mountains.

PoPs are generally advertised in the 60-80 range over the high
terrain, and 40-60% over the Piedmont. Deep layer shear will be
marginal for convective organization, but could be just enough to
support some weakly rotating cells capable of producing marginally
large hail and locally damaging wind gusts, especially over the SPC
has moved the Marginal category for severe storms south to include
all the CWFA and moved the Slight category south to cover the
northern zones where shear will be a bit higher. Convective coverage
will linger into the evening diminishing near midnight, but with
lapse rates remaining steep aloft and relatively high dewpoints
expected to persist, isolated activity could persist into the
overnight. Temps will continue to run roughly 5 degrees above climo
through the period.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 130 AM Sunday...A frontal zone pushes southeast early Mon
while upper heights rise and stg ridging builds atop the FA.
Westerly d/slope llvl flow develops as well, which will squelch any
sigfnt precip chances outside of isol mtn top convg across the srn
NC mtns during the afternoon. The weather becomes more active Mon
night into Tue with a warm front impinging upon the area and
crossing north. The guidance isn/t too keen a convec response
outside the mtns, where added mech lift will support deeper tstm
development and possibly hail production along with potentially stg
downbursts. All in all, Tue looks to remain dry across most locales.
Temps will remain well abv normal in this setup with maxes across
the non/mtns reaching the mid to even upper 80s and near 80 F across
the mtn valleys. Mins will also be held several degrees abv normal
each morning with a decent fog or low stratus probability.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 115 AM Sunday...A broad and wavy upper flow still looks to
persist thru the ext range, which will maintain unsettled and
convective activity each afternoon. A couple relatively weak sfc
fronts approach and stall over the FA thru the period as they run
into an Atl ridge. With good llvl moist adv and decent
destabilization each day, afternoon storms will be likely in a low
sheared enviroment. These storms will be mainly driven by afternoon
heating and weak sfc convg zones, thus expect generally pulse-type
storms, some of which could become strong enuf to produce large hail
and damaging outflows. By Fri, a more organized frontal system could
be in the works just west of the FA. The latest guidance has varying
ideas with the evolution of this system with the 00z GFS much faster
and stronger than the other op models. The ensembles point toward a
slower track as well, but in any case, it looks like an organized
tstm threat could be in the works Fri afternoon possibly lingering
into early Sat. With the llvl flow remaining generally sw/ly, expect
weak waa and good insol to allow for max/min temps well abv normal,
with cooler temps possible over the weekend behind a FROPA.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
At KCLT and Elsewhere: MVFR cigs did develop over the SC sites this
morning. Those clouds are starting to scatter out bur are making a
move NE as they do. Shouldn't be an MVFR cig at KCLT but FEW to SCT
MVFR are possible until around noon when they become low VFR.

At least scattered convection is expected to develop throughout the
afternoon, as an approaching cold front interacts with a moderately
unstable air mass. The convective mention is primarily limited to
VCTS, with Prob30s for TSRA after 21Z, although a tempo for TSRA is
included at KCLT from 21Z-01Z. Winds will become SW at around 10 kts
during late morning, with some gusts in the 15-20 kts range possible
in the Piedmont during the afternoon.

Convection will steadily diminish tonight, but lingering low level
moisture will create good potential for restrictions in fog and/or
stratus early Monday. At this point, there are questions as to how
widespread any restrictions will be, and will only advertise sub-VFR
category where it appears most likely, i.e., at KAVL and KCLT.

Outlook: Brief drying returns Monday before mainly diurnal
convection and associated brief restrictions return Tue-Thu.

&&

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

&&

SYNOPSIS...DEO
NEAR TERM...JDL/RWH
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...JDL/RWH

<!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
1242 PM EDT Sun May 1 2022

NCZ049-050-053-505-506-011730-
Buncombe NC-McDowell Mountains NC-Yancey NC-Eastern McDowell NC-
Mitchell NC-
1242 PM EDT Sun May 1 2022

...A strong thunderstorm will impact portions of southwestern
McDowell, south central Mitchell, northeastern Buncombe and
southeastern Yancey Counties through 130 PM EDT...

At 1241 PM EDT, the public reported a strong thunderstorm 15 miles
west of Marion, or 5 miles southwest of B.R. Parkway-Craggy To Little
Switzerland, moving northeast at 15 mph.

HAZARD...Pea size hail.

SOURCE...Public.

IMPACT...Minor damage to outdoor objects is possible.

Locations impacted include...
Marion, Black Mountain, Old Fort, Mount Mitchell State Park, B.R.
Parkway-Craggy To Little Switzerland, B.R. Parkway-East Asheville To
Craggy Gardens, Lake James, Montreat, Pleasant Gardens and Woodlawn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3558 8231 3570 8239 3592 8212 3567 8193
TIME...MOT...LOC 1641Z 240DEG 13KT 3568 8228

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...<30 MPH

JPT

<!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>