This alert expired on 18 May 2026 at 05:16 UTC. It is kept here as a record.
No stronger detection stands among the 21 recorded within 20 km of this point since 15 March 2026 — 6 others scored the same. 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 Warning issued May 18 at 12:06AM CDT until May 18 at 12:15AM CDT by NWS La Crosse WI
An estimated 148,338 people live within 50 km of this point.
Nearby, since 15 March 2026
- July 2, 2026 · score 22 · 12.4 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 out of 100, at 80 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 43 / 100 |
| Our confidence | 80% |
| Coordinates | 43.6490, -91.7732 |
| Nearest City | Winona (46 km) |
| Population Exposed | 148.3K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T05:06:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.edf2a7893903a84b57f2216c7993cb0b |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Fillmore, MN; Winona, MN; Winneshiek, IA |
| Headline | Severe Thunderstorm Warning issued May 18 at 12:06AM CDT until May 18 at 12:15AM CDT by NWS La Crosse WI |
| Expires | 2026-05-18T00:16:00-05:00 |
| SenderName | NWS La Crosse WI |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.edf2a7893903a84b57f2216c7993cb0b3c0b5baf.001.1","noaa_urn:oid:2.49.0.1.840.0.fbed2d6b6a44b3b2df2f0cd15235d68ffa89a502.001.1"] |
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.
Want to know when something happens in this area?
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 185 scientific monitoring sources.