Alert archive / Wyoming / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 22, NWS Riverton, WY

June 20, 2026Fremont County, Sweetwater County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jun 20, 2026, 7:43 PM MDT for Fremont County, Sweetwater County, Wyoming. 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: Jun 20, 2026, 7:43 PM MDT (01:43 UTC)
Expired: Jun 20, 2026, 8:30 PM MDT
In force: 47 min
Issued by: NWS Riverton, WY
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Fremont County, WY, Sweetwater County, WY

The radar

The Riverton/Lander radar (KRIW), 83 km from the middle of the area, began a volume at 01:42 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 20, 1:27 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

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 Riverton, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 20, 5:17 PM MDT, 2 hours 26 minutes earlier.

Area forecast discussion, Jun 20, 5:17 PM MDT, 2 hours 26 minutes before

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In the hours before

Local storm report, Jun 20, 4:41 PM MDT, 3 hours 2 minutes before

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Local storm report, Jun 20, 4:42 PM MDT, 3 hours 1 minute before

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<body>
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    <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.
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Local storm report, Jun 20, 5:20 PM MDT, 2 hours 23 minutes before

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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>
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Special weather statement, Jun 20, 5:23 PM MDT, 2 hours 20 minutes before

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<head>
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  <title>Service Notice</title>
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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>
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</body>
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Local storm report, Jun 20, 5:46 PM MDT, 1 hour 57 minutes before

<!doctype html>
<html lang="en">
<head>
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  <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, Jun 20, 5:59 PM MDT, 1 hour 44 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 Riverton, WY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 6:20 PM MDT	Severe Thunderstorm Warning	RIW	Lincoln	40 min
Jun 20, 6:37 PM MDT	Severe Thunderstorm Warning	RIW	Lincoln, Sublette, Sweetwater	38 min
Jun 20, 7:04 PM MDT	Severe Thunderstorm Warning	RIW	Fremont, Sublette, Sweetwater	41 min
Jun 20, 7:14 PM MDT	Special Weather Statement	RIW	Sweetwater	46 min
Jun 20, 8:21 PM MDT	Special Weather Statement	RIW		54 min
Jun 21, 3:00 PM MDT	Special Weather Statement	RIW	Fremont	45 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2026 Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.