Alert archive / South Dakota / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 187, NWS Aberdeen, SD

August 6, 2018Lyman County, South Dakota

NWS Aberdeen, SD issued this severe thunderstorm warning at Aug 6, 2018, 7:06 PM CDT for Lyman County, South Dakota. It was in force for 39 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: Aug 6, 2018, 7:06 PM CDT (00:06 UTC)
Expired: Aug 6, 2018, 7:45 PM CDT
In force: 39 min
Issued by: NWS Aberdeen, SD
Area: Storm-based polygon
Hail: 1.25 in
Wind: 70.0 mph

County Lyman County, SD

The radar

The Aberdeen radar (KABR), 207 km from the middle of the area, began a volume at 00:05 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, 0.1 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: 462 J/kg
Mixed-layer CIN: -81 J/kg
Mixed-layer LCL: 1801 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 53 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.6

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 Aug 6, 6:50 PM CDT, 16 minutes earlier.

Area forecast discussion, Aug 6, 6:50 PM CDT, 16 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, Aug 6, 9:34 AM CDT, 9 hours 32 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Aberdeen SD
934 AM CDT Mon Aug 6 2018

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-071445-
Traverse-Big Stone-Corson-Campbell-McPherson-Brown-Marshall-Roberts-
Walworth-Edmunds-Day-Dewey-Potter-Faulk-Spink-Clark-Codington-Grant-
Hamlin-Deuel-Stanley-Sully-Hughes-Hyde-Hand-Jones-Lyman-Buffalo-
934 AM CDT Mon Aug 6 2018 /834 AM MDT Mon Aug 6 2018/

This Hazardous Weather Outlook is for west central Minnesota,
central South Dakota, north central South Dakota and northeast
South Dakota.

.DAY ONE...Today and tonight.

Scattered showers and thunderstorms are expected across the region
this afternoon and tonight. The threat of severe weather is low.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

tdk

In the hours before

Special weather statement, Aug 6, 5:44 PM CDT, 1 hour 22 minutes before

Special Weather Statement
National Weather Service Aberdeen SD
544 PM CDT MON AUG 6 2018

SDZ045-062315-
Jones SD-
544 PM CDT MON AUG 6 2018

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL JONES COUNTY UNTIL 615 PM
CDT...

At 544 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 8 miles north of Draper to near Okaton.
Movement was east at 25 mph.

Dime size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Murdo, Draper, Okaton and Westover.

LAT...LON 4374 10075 4372 10079 4376 10081 4376 10084
      4379 10086 4378 10088 4380 10088 4379 10090
      4383 10093 4381 10095 4385 10099 4384 10103
      4386 10103 4385 10106 4388 10106 4410 10055
      4400 10036 4390 10037 4371 10074
TIME...MOT...LOC 2244Z 284DEG 22KT 4404 10051 4384 10096

KF

Special weather statement, Aug 6, 6:08 PM CDT, 58 minutes before

Special Weather Statement
National Weather Service Aberdeen SD
608 PM CDT MON AUG 6 2018

SDZ045-048-062345-
Lyman SD-Jones SD-
608 PM CDT MON AUG 6 2018

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL JONES AND
NORTHWESTERN LYMAN COUNTIES UNTIL 645 PM CDT...

At 607 PM CDT, Doppler radar was tracking a strong thunderstorm 8
miles north of Vivian, or 16 miles northwest of Presho, moving east
at 15 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

This storm will remain over mainly rural areas of east central Jones
and northwestern Lyman Counties.

LAT...LON 4406 10046 4414 10032 4409 10008 4392 10034
TIME...MOT...LOC 2307Z 282DEG 15KT 4405 10033

KF

Special weather statement, Aug 6, 6:21 PM CDT, 45 minutes before

Special Weather Statement
National Weather Service Aberdeen SD
621 PM CDT MON AUG 6 2018

SDZ048-070000-
Lyman SD-
621 PM CDT MON AUG 6 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN LYMAN COUNTY UNTIL
700 PM CDT...

At 621 PM CDT, Doppler radar was tracking a strong thunderstorm near
Vivian, or 12 miles northwest of Presho, moving east at 15 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
5 Mile Corner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4397 10037 4407 10036 4408 9998 4389 10018
TIME...MOT...LOC 2321Z 281DEG 15KT 4402 10025

KF

Special weather statement, Aug 6, 6:35 PM CDT, 31 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>

Special weather statement, Aug 6, 6:51 PM CDT, 15 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>

Local storm report, Aug 6, 6:57 PM CDT, 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>

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 7:12 PM CDT	Special Weather Statement	ABR	Lyman	18 min
Aug 6, 9:07 PM CDT	Special Weather Statement	ABR	Codington	38 min
Aug 6, 10:28 PM CDT	Special Weather Statement	ABR	Codington	32 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2018 Every severe thunderstorm warning in 2018

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.