Right now
The most recent data we hold from NOAA arrived 52 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 21 June 2026 at 03:00 UTC. It is kept here as a record.
It is the 2nd strongest of the 21 detections recorded within 20 km of this point since 13 May 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Watch issued June 20 at 5:36PM MDT until June 20 at 9:00PM MDT by NWS Riverton WY
Nearby, since 13 May 2026
- July 3, 2026 · score 22 · 0.0 km
- June 28, 2026 · score 22 · 0.0 km
- June 8, 2026 · score 16 · 0.0 km
How we know
10 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 22 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 22 / 100 |
| Legacy data-support index | 0.70/1 |
| Coordinates | 43.1000, -107.6000 |
| Nearest City | Casper (108 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-06-20T23:36:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.ad6227d3f793a957400e75a7463d5cba59a123d8.002.1 |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-06-20T23:36:00.000Z.
First archived: 2026-06-21T02:38:42.145Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Watch |
| Urgency | Future |
| Certainty | Possible |
| AreaDesc | Fremont, WY; Johnson, WY; Natrona, WY; Sweetwater, WY |
| Headline | Severe Thunderstorm Watch issued June 20 at 5:36PM MDT until June 20 at 9:00PM MDT by NWS Riverton WY |
| Expires | 2026-06-20T21:00:00-06:00 |
| SenderName | NWS Riverton WY |
| HasExactCoords | false |
| Iem TypeSummary | G |
| Iem Magnitude | 55 |
| Iem Unit | MPH |
| Iem City | 13 NNE Shoshoni |
| Iem County | Fremont |
| Iem State | WY |
| Iem Wfo | RIW |
| Iem Remark | Mesonet station PC455 Copper Mtn Rd (PC). |
| MergedSources | [{"id":"iem_G_42.490_-107.840_1781985600000","source":"iem","severity":"low","severityValue":25,"timestamp":1781985600000,"latitude":42.49,"longitude":-107.84},{"id":"iem_G_43.070_-108.470_1781986440000","source":"iem","severity":"low","severityValue":25,"timestamp":1781986440000,"latitude":43.07,"longitude":-108.47},{"id":"iem_G_43.090_-108.520_1781986200000","source":"iem","severity":"low","severityValue":25,"timestamp":1781986200000,"latitude":43.09,"longitude":-108.52},{"id":"iem_G_42.910_-108.030_1781988600000","source":"iem","severity":"low","severityValue":25,"timestamp":1781988600000,"latitude":42.91,"longitude":-108.03},{"id":"iem_G_43.030_-106.800_1781990520000","source":"iem","severity":"low","severityValue":25,"timestamp":1781990520000,"latitude":43.03,"longitude":-106.8},{"id":"iem_G_43.470_-108.260_1781986800000","source":"iem","severity":"low","severityValue":25,"timestamp":1781986800000,"latitude":43.47,"longitude":-108.26},{"id":"iem_G_43.030_-106.800_1781989920000","source":"iem","severity":"low","severityValue":25,"timestamp":1781989920000,"latitude":43.03,"longitude":-106.8},{"id":"iem_G_43.470_-108.230_1781987700000","source":"iem","severity":"low","severityValue":25,"timestamp":1781987700000,"latitude":43.47,"longitude":-108.23},{"id":"iem_G_43.420_-108.030_1781988000000","source":"iem","severity":"low","severityValue":25,"timestamp":1781988000000,"latitude":43.42,"longitude":-108.03}] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 8 March 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
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