Alert archive / South Dakota / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 1, NWS Aberdeen, SD

April 27, 2025Lyman County, South Dakota

NWS Aberdeen, SD issued this severe thunderstorm warning at Apr 27, 2025, 11:58 PM CDT for Lyman County, South Dakota. It was in force for 47 min. 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 27, 2025, 11:58 PM CDT (04:58 UTC)
Expired: Apr 28, 2025, 12:45 AM CDT
In force: 47 min
Issued by: NWS Aberdeen, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Lyman County, SD

The radar

The Aberdeen radar (KABR), 207 km from the middle of the area, began a volume at 05:00 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

Aberdeen, SD (KABR), launched 00:00Z, 5.0 hours before the alert went out and 160 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: 770 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 116 m²/s²
0-3 km storm-relative helicity: 124 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Aberdeen, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 27, 6:40 PM CDT, 5 hours 18 minutes earlier.

Area forecast discussion, Apr 27, 6:40 PM CDT, 5 hours 18 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 27, 3:09 AM CDT, 20 hours 49 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

Special weather statement, Apr 27, 10:49 PM CDT, 1 hour 9 minutes before

Special Weather Statement
National Weather Service Aberdeen SD
1049 PM CDT Sun Apr 27 2025

SDZ033-035-280415-
Hughes SD-Stanley SD-
1049 PM CDT Sun Apr 27 2025

...A STRONG THUNDERSTORM WILL IMPACT SOUTH CENTRAL STANLEY AND
NORTHWESTERN HUGHES COUNTIES THROUGH 1115 PM CDT...

At 1049 PM CDT, Doppler radar was tracking a strong thunderstorm over
Fort Pierre, moving northeast at 35 mph.

HAZARD...Wind gusts up to 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Grey Goose, Overlook Rec Area, Fort Pierre, and Pierre.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4434 10055 4455 10032 4455 10018 4445 10000
      4421 10037
TIME...MOT...LOC 0349Z 222DEG 32KT 4434 10039

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

13

Local storm report, Apr 27, 11:13 PM CDT, 45 minutes before

Preliminary Local Storm Report
National Weather Service Aberdeen SD
1113 PM CDT Sun Apr 27 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1055 PM     Hail             Pierre Regional Airport 44.38N 100.30W
04/27/2025  M1.25 Inch       Hughes             SD   Trained Spotter

            Most hail stones between nickel and quarter
            size.

&&

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 27, 10:49 PM CDT	Special Weather Statement	ABR	Hughes	26 min
Apr 28, 2:30 AM CDT	Wind Advisory	ABR	Brown, Campbell, Corson, Day, Dewey, Edmunds and 4 more	22 hr
Apr 28, 2:37 AM CDT	Special Weather Statement	ABR	Buffalo	23 min
Apr 28, 3:35 AM CDT	Special Weather Statement	ABR	Clark, Spink	40 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2025 Every severe thunderstorm warning in 2025

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.