Alert archive / North Carolina / Flash Flood Watches in 2020

Flash Flood Watch 8, NWS Greenville-Spartanburg, SC

May 27, 202010 counties in North Carolina; York County, South Carolina

NWS Greenville-Spartanburg, SC issued this flash flood watch at May 27, 2020, 3:37 AM EDT for 10 counties in North Carolina; York County, South Carolina. It took effect at May 27, 2020, 12:00 PM EDT. It was in force for 14 hr.

The area

The counties it named.

The facts

Issued: May 27, 2020, 3:37 AM EDT (07:37 UTC)
In effect from: May 27, 2020, 12:00 PM EDT
Expired: May 28, 2020, 2:00 AM EDT
In force: 14 hr
Issued by: NWS Greenville-Spartanburg, SC
Flood severity: None

Counties Alexander County, NC, Cabarrus County, NC, Catawba County, NC, Davie County, NC, Gaston County, NC, Iredell County, NC, Lincoln County, NC, Mecklenburg County, NC, Rowan County, NC, Union County, NC, York County, SC

The radar

The Greer radar (KGSP), 138 km from the middle of the area, began a volume at 07:40 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 7.6 hours before the alert went out and 111 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1209 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: -8 m²/s²
0-3 km storm-relative helicity: 23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before this flash flood watch went out at May 27, 3:12 AM EDT, 25 minutes earlier.

Area forecast discussion, May 27, 3:12 AM EDT, 25 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, May 27, 3:28 AM EDT, 9 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>

In the hours before

Local storm report, May 26, 11:37 PM 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 Greenville-Spartanburg, SC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 27, 5:56 PM EDT	Areal Flood Advisory	GSP	Mecklenburg, Union	9 hr
May 27, 6:12 PM EDT	Flash Flood Warning	GSP	Mecklenburg	3 hr
May 27, 6:43 PM EDT	Areal Flood Advisory	GSP	Cabarrus, Rowan	9 hr
May 27, 7:15 PM EDT	Flash Flood Warning	GSP	Mecklenburg	3 hr

Nearby

Flash Flood Watches in North Carolina, 2020 Flash Flood Watches in South Carolina, 2020 Every flash flood watch in 2020

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.