This alert expired on 18 May 2026 at 13:00 UTC. It is kept here as a record.
It is the 7th strongest of the 42 detections recorded within 20 km of this point since 18 May 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 18 at 7:21AM CDT until May 18 at 8:00AM CDT by NWS St Louis MO
An estimated 173,218 people live within 50 km of this point.
Nearby, since 18 May 2026
- June 1, 2026 · score 43 · 1.5 km
- May 22, 2026 · score 43 · 14.5 km
- June 8, 2026 · score 16 · 16.0 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 | 39.1967, -90.7850 |
| Nearest City | Wentzville (43 km) |
| Population Exposed | 173.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T12:21:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.a9ceb6a64faf074da866360ef15ded096768f8fe.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Calhoun, IL; Greene, IL; Jersey, IL; Lincoln, MO; Pike, MO |
| Headline | Severe Thunderstorm Warning issued May 18 at 7:21AM CDT until May 18 at 8:00AM CDT by NWS St Louis MO |
| Expires | 2026-05-18T08:00:00-05:00 |
| SenderName | NWS St Louis MO |
| HasExactCoords | true |
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.