Alert archive / South Carolina / Flash Flood Warnings in 2017

Flash Flood Warning 1, NWS Charleston, SC

April 24, 2017Charleston County, South Carolina

NWS Charleston, SC issued this flash flood warning at Apr 24, 2017, 7:58 AM EDT for Charleston County, South Carolina. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 24, 2017, 7:58 AM EDT (11:58 UTC)
Expired: Apr 24, 2017, 10:00 AM EDT
In force: 2 hr
Issued by: NWS Charleston, SC
Area: Storm-based polygon
Flood severity: None

County Charleston County, SC

The radar

The Charleston,SC radar (KCLX), 103 km from the middle of the area, began a volume at 12:00 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 00:00Z, 12.0 hours before the alert went out and 18 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 487 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 921 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 112 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.5

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning 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 flash flood warning went out at Apr 24, 7:54 AM EDT, 4 minutes earlier.

Area forecast discussion, Apr 24, 7:54 AM EDT, 4 minutes before

<!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>

Hazardous weather outlook, Apr 24, 3:58 AM EDT, 4 hours before

<!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>

The office that day

Everything else NWS Charleston, SC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 24, 3:56 AM EDT	Coastal Flood Advisory	CHS		5 hr
Apr 24, 5:21 AM EDT	Areal Flood Advisory	CHS	Charleston	39 min
Apr 24, 6:01 AM EDT	Areal Flood Advisory	CHS	Charleston	119 min
Apr 24, 8:10 AM EDT	Areal Flood Advisory	CHS	Berkeley	65 min
Apr 24, 8:50 AM EDT	Special Marine Warning	CHS		115 min
Apr 24, 9:13 AM EDT	Areal Flood Advisory	CHS	Berkeley, Charleston	2 hr
Apr 24, 9:46 AM EDT	Flash Flood Warning	CHS	Charleston	89 min
Apr 24, 3:12 PM EDT	Coastal Flood Advisory	CHS		7 hr
Apr 24, 5:31 PM EDT	Areal Flood Advisory	CHS	Colleton, Dorchester	89 min
Apr 24, 6:55 PM EDT	Areal Flood Advisory	CHS	Colleton, Dorchester	95 min
Apr 23, 9:04 PM EDT	Areal Flood Advisory	CHS	Jenkins	86 min

Nearby

Flash Flood Warnings in South Carolina, 2017 Every flash flood warning 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.