Special Weather Statement, NWS Charleston, SC

Area Forecast Discussion
National Weather Service Charleston SC
355 PM EDT Sun Jul 9 2017

.SYNOPSIS...
The area will remain situated between an inland trough and
Atlantic high pressure for the rest of the week before a cold
front approaches early next week.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
This Evening: The area will remain between high pressure over
the western Atlantic and a broad longwave trough over the East
Conus. At the sfc, a front has stalled over the Midlands while
becoming parallel to the flow aloft. Despite some high clouds
over the area for much of the day, sufficient heating and
moisture return has occurred southeast of the stationary front
to help produce a few showers and thunderstorms just upstream
of our area. Convective activity should increase over inland
parts of the area late afternoon into the evening where the
combination of weak forcing associated with the stationary
front, isentropic ascent and SBCAPES range around 2000-2500 J/kg.
Given weak shear, slower storm motion and PWATs near 2.0 inches,
brief heavy rainfall will be possible with pulse/multicell type
thunderstorms. A few thunderstorms could also produce strong
and/or damaging wind gusts into the evening, but the overall
threat is somewhat low given DCAPE values well below 1000 J/kg.

Tonight: Precip coverage and location becomes a bit more challenging
to forecast. However, there are signs that suggest chances or
showers and/or thunderstorms could continue through much of the
night, especially over parts of Southeast South Carolina where a
fair amount of instability will remain under increasing cloud cover.
Guidance suggests showers and/or thunderstorms should develop north
and northwest of the area along the stationary boundary this evening
and early tonight while favorable upper-lvl divergence persists in
the right-rear quadrant of a passing 250mb jet. Despite weak flow, a
few of these showers/thunderstorms could shift into the area overnight
where modest isentropic lift persists and sufficient instability as
well as PWATs near 2.0 inches support ongoing conditions. However,
shear and instability are not all the conducive for a strong and/or
severe thunderstorm. Overnight lows will remain mild, in the low/mid
70s inland to upper 70s closer to the coast.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
A broad upper trough pattern will linger across the area Monday
into Tuesday, maintaining greater than normal cloud cover and
higher chances for showers and tstms. PWATs in excess of 2" on
Monday will drop to around 1.8" Tuesday as the upper trough
begins to erode and a ridge starts to build. We show some likely
pops across inland areas on Tuesday with 40-50% on Tuesday.
Highs Monday and Tuesday will be in the upper 80s to lower 90s.

For Wednesday it appears convective coverage will be more
typical for mid-July given the building deep layered ridge.
Highs will be in the lower 90s most areas.

Isolated severe thunderstorms are possible each afternoon and
evening. There are currently no strong signals for a more
significant severe threat on any given day.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Atlantic high pressure will prevail through Friday before another
upper trough, cold front and pre-frontal trough return next weekend.
This pattern should lead to generally typical summertime weather
through Thursday with increasing rain chances late in the week
through the weekend. High temperatures should mostly be near to
slightly above normal in the mid 90s with heat indices close to 105
degrees while low temperatures remain above normal in the mid to
upper 70s.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR conditions are expected for the next couple hours at both
CHS and SAV terminals. Tempo MVFR cigs/vsbys are then possible
at either terminal, 22-24z at CHS and 21-24z at SAV, for showers
and thunderstorms that develop inland and slowly shift toward
the coast this evening. Showers could linger over the area
through a large part of the night, thus VCSH has been included
at both terminals into Monday morning. VFR conditions should
then prevail late Monday morning into early afternoon.

Extended Aviation Outlook: Flight restrictions at times through
the period, mainly from afternoon/evening showers and
thunderstorms.

&&

.MARINE...
This Evening and Tonight: High pressure will prevail over the
coastal waters while a stationary front remains well inland. The
pressure gradient across the marine zones will be weak through
tonight, supporting winds/seas that remain well below Small
Craft Advisory levels. In general, south-southwest winds should
be no higher than 10-15 kts. Seas will range between 2-4 feet,
highest in offshore Georgia waters. Shower and thunderstorm
coverage could increase overnight, especially over northern
South Carolina waters.

Monday through Saturday: The area will remain between inland
troughing and Atlantic high pressure. This will maintain a
moderate southerly flow through the period, enhanced at times
due to the afternoon sea breeze and nighttime surging.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

NEAR TERM...DPB
SHORT TERM...JRL
LONG TERM...RJB
AVIATION...DPB/JRL
MARINE...DPB/JRL

<!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>