Alert archive / South Dakota / Flash Flood Warnings in 2020

Flash Flood Warning 3, NWS Aberdeen, SD

July 24, 2020Brown County, McPherson County, South Dakota

NWS Aberdeen, SD issued this flash flood warning at Jul 24, 2020, 11:45 PM CDT for Brown County, McPherson County, South Dakota. It was in force for 6 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: Jul 24, 2020, 11:45 PM CDT (04:45 UTC)
Expired: Jul 25, 2020, 5:45 AM CDT
In force: 6 hr
Issued by: NWS Aberdeen, SD
Area: Storm-based polygon
Flood severity: None

Counties Brown County, SD, McPherson County, SD

The radar

The Aberdeen radar (KABR), 38 km from the middle of the area, began a volume at 04:46 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

Aberdeen, SD (KABR), launched 00:00Z, 4.8 hours before the alert went out and 92 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: 2265 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 1499 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

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.

In the hours before

Local storm report, Jul 24, 8:04 PM CDT, 3 hours 41 minutes before

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Local storm report, Jul 24, 8:10 PM CDT, 3 hours 35 minutes before

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Local storm report, Jul 24, 10:26 PM CDT, 1 hour 19 minutes before

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Local storm report, Jul 24, 10:37 PM CDT, 1 hour 8 minutes before

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      <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.
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      <p id="message2">
        Please try again in a few minutes.
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Local storm report, Jul 24, 11:10 PM CDT, 35 minutes before

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<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.
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        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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Local storm report, Jul 24, 11:12 PM CDT, 33 minutes before

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<head>
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</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>
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The office that day

Everything else NWS Aberdeen, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 24, 10:04 PM CDT	Severe Thunderstorm Warning	ABR	Brown, McPherson	41 min
Jul 24, 10:58 PM CDT	Areal Flood Warning	ABR	Brown, McPherson	36 hr
Jul 25, 7:08 AM CDT	River Flood Warning	ABR	Brown	4 days
Jul 25, 1:24 PM CDT	River Flood Warning	ABR	Brown	4 days
Jul 25, 5:07 PM CDT	Severe Thunderstorm Warning	ABR	Corson	38 min
Jul 25, 5:45 PM CDT	Severe Thunderstorm Warning	ABR	Corson	60 min
Jul 25, 6:57 PM CDT	Severe Thunderstorm Warning	ABR	Campbell, Corson	48 min

Nearby

Flash Flood Warnings in South Dakota, 2020 Every flash flood warning 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.