Alert archive / Wyoming / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 13, NWS Riverton, WY

June 20, 2026Johnson County, Natrona County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jun 20, 2026, 3:46 PM MDT for Johnson County, Natrona County, Wyoming. It was in force for 44 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, 3:46 PM MDT (21:46 UTC)
Expired: Jun 20, 2026, 4:30 PM MDT
In force: 44 min
Issued by: NWS Riverton, WY
Area: Storm-based polygon
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Johnson County, WY, Natrona County, WY

The radar

The Riverton/Lander radar (KRIW), 152 km from the middle of the area, began a volume at 21:50 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, 11:53 AM MDT, 3 hours 53 minutes earlier.

Area forecast discussion, Jun 20, 11:53 AM MDT, 3 hours 53 minutes before

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In the hours before

Special weather statement, Jun 20, 2:26 PM MDT, 1 hour 20 minutes before

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Special weather statement, Jun 20, 2:28 PM MDT, 1 hour 18 minutes before

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Special weather statement, Jun 20, 2:32 PM MDT, 1 hour 14 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, Jun 20, 2:48 PM MDT, 58 minutes before

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Local storm report, Jun 20, 3:21 PM MDT, 25 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.
      </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, 3:33 PM MDT, 13 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.
      </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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The office that day

Everything else NWS Riverton, WY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 1:06 PM MDT	Special Weather Statement	RIW	Fremont	39 min
Jun 20, 1:15 PM MDT	Special Weather Statement	RIW		45 min
Jun 20, 1:18 PM MDT	Severe Thunderstorm Warning	RIW	Fremont	42 min
Jun 20, 1:43 PM MDT	Special Weather Statement	RIW		17 min
Jun 20, 1:47 PM MDT	Special Weather Statement	RIW	Hot Springs	43 min
Jun 20, 2:00 PM MDT	Special Weather Statement	RIW	Fremont	60 min
Jun 20, 2:01 PM MDT	Special Weather Statement	RIW	Sublette	29 min
Jun 20, 2:05 PM MDT	Special Weather Statement	RIW		25 min
Jun 20, 2:15 PM MDT	Severe Thunderstorm Warning Considerable damage threat	RIW	Fremont, Hot Springs, Natrona	45 min
Jun 20, 2:26 PM MDT	Special Weather Statement	RIW	Natrona	34 min
Jun 20, 2:28 PM MDT	Special Weather Statement	RIW	Sublette	32 min
Jun 20, 2:32 PM MDT	Special Weather Statement	RIW	Hot Springs, Washakie	43 min
Jun 20, 2:48 PM MDT	Severe Thunderstorm Warning	RIW	Hot Springs, Washakie	42 min
Jun 20, 2:59 PM MDT	Severe Thunderstorm Warning	RIW	Fremont, Natrona	61 min
Jun 20, 3:29 PM MDT	Severe Thunderstorm Warning	RIW	Big Horn, Washakie	46 min
Jun 20, 3:56 PM MDT	Severe Thunderstorm Warning Considerable damage threat	RIW	Natrona	34 min
Jun 20, 4:14 PM MDT	Severe Thunderstorm Warning	RIW	Big Horn, Johnson, Washakie	46 min
Jun 20, 4:29 PM MDT	Severe Thunderstorm Warning Considerable damage threat	RIW	Johnson	46 min
Jun 20, 5:14 PM MDT	Severe Thunderstorm Warning Considerable damage threat	RIW	Johnson	61 min
Jun 20, 5:23 PM MDT	Special Weather Statement	RIW	Lincoln	67 min
Jun 20, 5:35 PM MDT	Severe Thunderstorm Warning	RIW	Lincoln, Sublette	25 min
Jun 20, 5:59 PM MDT	Special Weather Statement	RIW	Sublette	46 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.