This alert expired on 1 June 2026 at 14:30 UTC. It is kept here as a record.
It is the 7th strongest of the 44 detections recorded within 20 km of this point since 17 April 2026. The last comparable one was on 22 May 2026. 30 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued June 1 at 7:38AM CDT until June 1 at 9:30AM CDT by NWS St Louis MO
An estimated 173,218 people live within 50 km of this point.
Nearby, since 17 April 2026
- May 18, 2026 · score 43 · 1.5 km
- May 22, 2026 · score 43 · 13.0 km
- May 21, 2026 · score 48 · 15.9 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 85 % 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 | 85% |
| Coordinates | 39.1829, -90.7857 |
| Nearest City | Wentzville (42 km) |
| Population Exposed | 173.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-01T12:38:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.9ce4fad519d6dd67a3a3752a1ad049bb615db5a8.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Calhoun, IL; Greene, IL; Jersey, IL; Lincoln, MO; Pike, MO |
| Headline | Flash Flood Warning issued June 1 at 7:38AM CDT until June 1 at 9:30AM CDT by NWS St Louis MO |
| Expires | 2026-06-01T09:30:00-05:00 |
| SenderName | NWS St Louis MO |
| HasExactCoords | true |
| Iem TypeSummary | D |
| Iem City | 1 W Overland |
| Iem County | St. Louis |
| Iem State | MO |
| Iem Wfo | LSX |
| Iem Remark | Tree fell into a home on Maddox and Fowler. Time estimated from radar. |
| MergedSources | [{"id":"iem_D_38.700_-90.390_1780311780000","source":"iem","severity":"low","severityValue":25,"timestamp":1780311780000,"latitude":38.7,"longitude":-90.39}] |
Safety Information
During flooding: never walk, swim, or drive through floodwaters. Six inches of moving water can knock you down, and one foot of water can sweep away a vehicle. Move to higher ground if waters rise. After flooding, avoid contact with floodwater which may contain sewage, chemicals, or debris. Follow local emergency service guidance.
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.