Alert archive / Georgia / Special Weather Statements in 2017

Special Weather Statement, NWS Charleston, SC

August 9, 2017Candler County, Georgia

NWS Charleston, SC issued this special weather statement at Aug 9, 2017, 1:22 PM EDT for Candler County, Georgia. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 9, 2017, 1:22 PM EDT (17:22 UTC)
Expired
Aug 9, 2017, 2:00 PM EDT
In force
38 min
Issued by
NWS Charleston, SC

County Candler County, GA

The radar

The Charleston,SC radar (KCLX), 94 km from the middle of the area, began a volume at 17:25 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 5.4 hours before the alert went out and 195 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Charleston AFB, SC at 12:00Z on 2017-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 662 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Charleston AFB, SC at 12:00Z on 2017-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
662 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
627 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

<!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>

What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Charleston, SC wrote its last area forecast discussion before this special weather statement went out at Aug 8, 3:59 PM EDT, 21 hours 23 minutes earlier.

Area forecast discussion, Aug 8, 3:59 PM EDT, 21 hours 23 minutes before
Area Forecast Discussion
National Weather Service Charleston SC
359 PM EDT Tue Aug 8 2017

.SYNOPSIS...
A front will linger nearby through Thursday before lifting back
north. High pressure will rebuild Friday through early next
week. A cold front could approach the area next Monday or
Tuesday.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Remainder of the afternoon: The combination of weak upper forcing,
deep moisture and a web of mesoscale boundary interactions will
keep numerous showers and tstms going over our SC zones. Rain will
be heavy at times with localized flooding expected will training
convection and in association with strongest storms. The latest
HRRR model runs suggest the brunt of the heavier rains will slide
offshore between around 22Z or 23Z at the latest. Much of this rain
was falling during the low tide cycle along the coast, but rainfall
rates were still impressive and will need to be monitored.

Tonight: High resolution models continue to show scattered convection
over southeast GA early this evening, likely decreasing after 01Z
with the loss of diurnal heating. Across SC, showers and storms are
expected to be mostly offshore at dusk to the north of the Savannah
River, leaving areas of lighter rains with a few pockets of convective
rains still possible.

A weak cold front should drift over the forecast area tonight while
deep moisture remains intact. A late night short wave in the
mid levels may keep some scattered rains/showers around late in
the night. We maintained chance POPs many areas after midnight
which maintained good persistence with the previous forecast.
Low temps will be in the lower to mid 70s and with the frontal
zone in the vicinity, there could be patches of low clouds and
patchy fog over inland areas, mainly north of I-16.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
A relatively wet pattern is expected. A weak mid-level trough will
remain over our region while several shortwaves traverse the trough.
The shortwaves on Wednesday and Thursday might be stronger and more
noticeable to our weather. At the surface, a stationary front will
linger nearby through Thursday, then transition into a warm front
and rapidly move northward Thursday night into Friday. Deep moisture
is in place with PWATs above 2.0", perhaps getting up to 2.3" at
times. Lift should be decent due to the vicinity of the front,
enhanced by cold pool boundaries. Numerous showers are expected,
with the greatest potential being in the afternoon and evening.
Instability is moderate for this time of year and models show it
increasing into Friday, especially during peak heating. The overall
risk of severe weather is low. Heavy rain appears to be the main
threat, especially due to weak steering flow. Local flooding is not
out of the question, especially in storms that train. Cloud cover
and shower coverage should keep highs several degrees below normal.
Lows will be in the lower to mid 70s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Weak upper ridging over the weekend will result in a slight increase
in temperatures and a more typical summertime convection pattern
favoring afternoon and evening hours.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
Through sunset, the coastal corridor will see showers and storms
scattered to numerous at times, especially north of the Savannah
River. Thunderstorms will produce heavy rains at times, lowering
vsbys briefly below 2 miles at times. This evening, models
differ on convective patterns but we carried prevailing showers
at KCHS and vicinity showers at KSAV in the TAFs. Thunder is
certainly still possible into the evening hours.

We will also need to watch for MVFR/IFR cigs as a light surface
wind shift to north is possible. While some of the numerical
guidance hints at lower cigs, since most of the forecast soundings
did not show tighter low level inversions we opted to wait on
any introductions for now.

Extended Aviation Outlook: Showers and tstms may occasionally affect
the terminals, with temporary visibility restrictions the primary
concern.

&&

.MARINE...
Tonight: Synoptic winds have decreased today and mainly light
winds are expected tonight, becoming variable late as a weak
front drops in. The main hazards tonight will be scattered to
numerous showers and storms producing frequent cloud to water
lightning strikes and heavy rains with low visibilities.

Wednesday through Sunday: A front will linger nearby through
Thursday before lifting back north. Atlantic high pressure will
become the more dominant feature Friday through the weekend. A weak
pressure gradient will result in winds at or below 10 kt with weak
afternoon sea breezes close to the coast. Conditions may be
favorable for waterspouts Wednesday morning with light and
variable winds and deep moist vertical profiles.

Atlantic high pressure will remain the dominant marine feature
Wednesday through Sunday, resulting in south to southwest winds
at or below 10 kt and weak afternoon sea breezes along the
coast.

&&

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

&&

NEAR TERM...
SHORT TERM...MS
LONG TERM...MS
AVIATION...MS
MARINE...MS
Hazardous weather outlook, Aug 8, 4:06 PM EDT, 21 hours 16 minutes before
Hazardous Weather Outlook
National Weather Service Charleston SC
406 PM EDT Tue Aug 8 2017

GAZ087-088-099>101-116>119-SCZ040-042>045-047>052-092015-
Jenkins-Screven-Candler-Bulloch-Effingham-Inland Bryan-Coastal Bryan-
Inland Chatham-Coastal Chatham-Allendale-Hampton-Inland Colleton-
Dorchester-Inland Berkeley-Inland Jasper-Beaufort-Coastal Colleton-
Charleston-Coastal Jasper-Tidal Berkeley-
406 PM EDT Tue Aug 8 2017

This Hazardous Weather Outlook is for southeast Georgia and
southeast South Carolina.

.DAY ONE...Tonight.

Heavy Rainfall: A front will move into the area this afternoon and
numerous to widespread showers and thunderstorms are expected to
continue through the early evening hours. Locally heavy rain will be
possible and could cause minor flooding of low lying and poor
drainage areas across southeast South Carolina and southeast Georgia.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter assistance is not anticipated at this time.

AMZ330-350-352-354-374-GAZ114-115-137>141-092015-
Charleston Harbor-
Waters from South Santee River to Edisto Beach SC out 20 nm-
Waters from Edisto Beach SC to Savannah GA out 20 nm-
Waters from Savannah GA to Altamaha Sound GA out 20 nm...including
Grays Reef National Marine Sanctuary-
Waters from Savannah GA to Altamaha Sound GA extending from 20 to
60 nm-Tattnall-Evans-Long-Inland Liberty-Coastal Liberty-
Inland McIntosh-Coastal McIntosh-
406 PM EDT Tue Aug 8 2017

This Hazardous Weather Outlook is for Atlantic coastal waters and
southeast Georgia.

.DAY ONE...Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter assistance is not anticipated at this time.

Nearby

Special Weather Statements in Georgia, 2017Every special weather statement in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.