This alert expired on 13 May 2026 at 21:45 UTC. It is kept here as a record.
Another comparable one was recorded here earlier the same day. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 13 at 3:17PM MDT until May 13 at 3:45PM MDT by NWS Salt Lake City UT
An estimated 229,613 people live within 50 km of this point.
How we know
Confirmed by 4 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 90 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 43 / 100 |
| Our confidence | 90% |
| Coordinates | 41.4577, -112.4091 |
| Nearest City | Brigham City (33 km) |
| Population Exposed | 229.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-13T21:17:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.e1881046c880438e614cbcc87415e36c |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Box Elder, UT; Bannock, ID; Bingham, ID; Blaine, ID; Bonneville, ID; Butte, ID; Caribou, ID; Cassia, ID; Jefferson, ID; Minidoka, ID; Oneida, ID; Power, ID; Davis, UT; Salt Lake, UT; Tooele, UT; Utah, UT and 4 more areas |
| Headline | Severe Thunderstorm Warning issued May 13 at 3:17PM MDT until May 13 at 3:45PM MDT by NWS Salt Lake City UT |
| Expires | 2026-05-13T15:45:00-06:00 |
| SenderName | NWS Salt Lake City UT |
| HasExactCoords | true |
| MergedCount | 7 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.e1881046c880438e614cbcc87415e36c78eebc66.001.1","noaa_urn:oid:2.49.0.1.840.0.4492894b0954e5e16352cc176c8357e96fa31e24.001.1","noaa_urn:oid:2.49.0.1.840.0.473e7e93b75114d50a1703ba33edfc1e174e5516.001.1","noaa_urn:oid:2.49.0.1.840.0.7ecb4027ebb6c26cac9ded7b7e960bba0c8ac935.001.1","noaa_urn:oid:2.49.0.1.840.0.5256e5173911f1e764e2e3b64dc75f3a9394a8ae.001.1","noaa_urn:oid:2.49.0.1.840.0.166c50798517375f01fdebd46ec9556d4d31c7d7.001.1","noaa_urn:oid:2.49.0.1.840.0.a7686c3538365a279d49ed20327d6d8bce9550b1.001.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 58 |
| Iem Unit | MPH |
| Iem City | 9 N Lakeside |
| Iem County | Box Elder |
| Iem State | UT |
| Iem Wfo | SLC |
| Iem Remark | Mesonet station GNI Gunnison Island. |
| MergedSources | [{"id":"iem_G_41.050_-113.070_1778702760000","source":"iem","severity":"low","severityValue":25,"timestamp":1778702760000,"latitude":41.05,"longitude":-113.07},{"id":"iem_G_41.070_-112.590_1778704800000","source":"iem","severity":"low","severityValue":25,"timestamp":1778704800000,"latitude":41.07,"longitude":-112.59},{"id":"iem_G_41.330_-112.850_1778704500000","source":"iem","severity":"low","severityValue":25,"timestamp":1778704500000,"latitude":41.33,"longitude":-112.85}] |
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 10 February 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.
Calamity.live data shows a weather event with CalamityScore 43/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.