Alert archive / Tennessee / Flash Flood Watches in 2020

Flash Flood Watch 3, NWS Nashville, TN

March 24, 202011 counties in Tennessee

NWS Nashville, TN issued this flash flood watch at Mar 24, 2020, 3:12 AM CDT for 11 counties in Tennessee. It took effect at Mar 24, 2020, 7:00 AM CDT. It was in force for 15 hr.

The area

The counties it named.

The facts

Issued
Mar 24, 2020, 3:12 AM CDT (08:12 UTC)
In effect from
Mar 24, 2020, 7:00 AM CDT
Expired
Mar 24, 2020, 10:28 PM CDT
In force
15 hr
Issued by
NWS Nashville, TN
Flood severity
None

Counties Bedford County, TN, Coffee County, TN, Giles County, TN, Grundy County, TN, Lawrence County, TN, Lewis County, TN, Marshall County, TN, Maury County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN

The radar

The Northeast Alabama radar (KHTX), 77 km from the middle of the area, began a volume at 08:13 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 8.2 hours before the alert went out and 304 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, Peachtre/Fal Fld, GA at 00:00Z on 2020-03-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 180 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, Peachtre/Fal Fld, GA at 00:00Z on 2020-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 280 square meters per square second.1939587897Sfc1 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
180 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
697 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
280 m²/s²
0-3 km storm-relative helicity
335 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.8

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 Nashville, TN wrote its last area forecast discussion before this flash flood watch went out at Mar 24, 1:12 AM CDT, 2 hours earlier.

Area forecast discussion, Mar 24, 1:12 AM CDT, 2 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>
Hazardous weather outlook, Mar 23, 5:00 AM CDT, 22 hours 12 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>

The office that day

Everything else NWS Nashville, TN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 24, 7:24 AM CDTRiver Flood AdvisoryOHXDecatur, Hardin, Perry, Wayne24 hr
Mar 24, 7:33 AM CDTRiver Flood AdvisoryOHXGiles65 hr
Mar 24, 8:37 AM CDTAreal Flood AdvisoryOHXGiles, Lawrence, Wayne3 hr
Mar 24, 9:14 AM CDTRiver Flood AdvisoryOHXPerry67 hr
Mar 24, 3:21 PM CDTRiver Flood AdvisoryOHXDavidson4 days
Mar 24, 3:26 PM CDTRiver Flood AdvisoryOHXHickman22 hr
Mar 24, 4:50 PM CDTSpecial Weather StatementOHXLewis, Wayne25 min
Mar 24, 4:57 PM CDTSevere Thunderstorm WarningOHXLawrence, Lewis, Wayne33 min
Mar 24, 5:27 PM CDTTornado WarningOHXGiles, Lawrence33 min
Mar 24, 5:39 PM CDTAreal Flood AdvisoryOHXClay, Jackson, Macon, Overton, Pickett, Smith and 3 more3 hr
Mar 24, 5:42 PM CDTAreal Flood AdvisoryOHXBedford, Giles, Lawrence, Lewis, Marshall, Maury and 1 more3 hr
Mar 24, 5:49 PM CDTAreal Flood AdvisoryOHXDavidson, Rutherford, Sumner, Williamson, Wilson3 hr
Mar 24, 5:52 PM CDTFlash Flood WarningOHXGiles, Lawrence, Marshall, Maury83 min
Mar 24, 6:00 PM CDTSevere Thunderstorm WarningOHXGiles, Marshall30 min
Mar 24, 6:14 PM CDTFlash Flood WarningOHXDavidson, Macon, Smith, Sumner, Trousdale, Wilson91 min

Nearby

Flash Flood Watches in Tennessee, 2020Every 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.