Right now
The most recent data we hold from NOAA arrived 40 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 31 May 2026 at 23:45 UTC. It is kept here as a record.
No stronger detection stands among the 40 recorded within 20 km of this point since 25 May 2026 — one other scored the same. Another comparable one was recorded here earlier the same day. 7 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued May 31 at 6:07PM CDT until May 31 at 6:45PM CDT by NWS Sioux Falls SD
An estimated 15,669 people live within 50 km of this point.
Nearby, since 25 May 2026
- May 31, 2026 · score 58 · 2.1 km
- May 31, 2026 · score 43 · 13.1 km
- June 1, 2026 · score 40 · 14.5 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 58 out of 100, at 79 % 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 | Critical |
| Calamity Score (ours) | 58 / 100 |
| Our confidence | 79% |
| Coordinates | 43.5900, -97.4500 |
| Nearest City | Mitchell (49 km) |
| Population Exposed | 15.7K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-31T23:07:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.cafbbf5d74d2cd0c75fff33ccd503cf904e8677f.001.1 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | McCook, SD |
| Headline | Tornado Warning issued May 31 at 6:07PM CDT until May 31 at 6:45PM CDT by NWS Sioux Falls SD |
| Expires | 2026-05-31T18:45:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
Safety Information
If a tornado warning is issued: go to a basement or an interior room on the lowest floor, away from windows. A vehicle and a mobile home are not shelter. Cover your head and neck. Wait for the official all-clear before going outside, and watch for downed power lines and gas leaks afterwards.
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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