Alert archive / Wyoming / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 33, NWS Riverton, WY

June 17, 2025Fremont County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jun 17, 2025, 1:33 PM MDT for Fremont County, Wyoming. It was in force for 27 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 17, 2025, 1:33 PM MDT (19:33 UTC)
Expired: Jun 17, 2025, 2:00 PM MDT
In force: 27 min
Issued by: NWS Riverton, WY
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Fremont County, WY

The radar

The Riverton/Lander radar (KRIW), 13 km from the middle of the area, began a volume at 19:33 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

Riverton, WY (KRIW), launched 12:00Z, 7.6 hours before the alert went out and 19 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1381 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

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 Riverton, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 16, 4:32 PM MDT, 21 hours 1 minute earlier.

Area forecast discussion, Jun 16, 4:32 PM MDT, 21 hours 1 minute before

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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 16, 7:06 PM MDT	Special Weather Statement	RIW	Natrona	39 min
Jun 16, 7:25 PM MDT	Special Weather Statement	RIW	Natrona	35 min
Jun 16, 7:32 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	43 min
Jun 16, 7:33 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	27 min
Jun 16, 7:41 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	34 min
Jun 16, 7:58 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	47 min
Jun 16, 8:07 PM MDT	Special Weather Statement	RIW	Natrona	23 min
Jun 16, 8:09 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	36 min
Jun 16, 8:22 PM MDT	Special Weather Statement	RIW	Natrona	38 min
Jun 16, 8:37 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	38 min
Jun 17, 1:24 PM MDT	Special Weather Statement	RIW	Fremont	36 min
Jun 17, 1:56 PM MDT	Special Weather Statement	RIW	Fremont	34 min
Jun 17, 2:00 PM MDT	Special Weather Statement	RIW	Natrona	30 min
Jun 17, 2:09 PM MDT	Special Weather Statement	RIW	Fremont	36 min
Jun 17, 2:19 PM MDT	Special Weather Statement	RIW		26 min
Jun 17, 2:33 PM MDT	Severe Thunderstorm Warning	RIW	Johnson, Natrona	27 min
Jun 17, 2:53 PM MDT	Severe Thunderstorm Warning	RIW	Johnson, Natrona	19 min
Jun 17, 2:54 PM MDT	Special Weather Statement	RIW	Natrona	36 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 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.