Right now
The most recent data we hold from NOAA arrived 2 hours ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
2 other detections within 20 km in the last 24 hours, the nearest 14 km from here.
This alert expired on 1 June 2026 at 01:30 UTC. It is kept here as a record.
No stronger detection stands among the 43 recorded within 20 km of this point since 15 March 2026 — 3 others scored the same. Another comparable one was recorded here earlier the same day. 16 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued May 31 at 7:42PM CDT until May 31 at 8:30PM CDT by NWS Sioux Falls SD
An estimated 171,544 people live within 50 km of this point.
Nearby, since 15 March 2026
- May 31, 2026 · score 43 · 16.1 km
- September 12, 2026 · score 37 · 17.0 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 67 out of 100, at 84 % 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) | 67 / 100 |
| Our confidence | 84% |
| Coordinates | 43.6200, -97.1060 |
| Nearest City | Sioux Falls (32 km) |
| Population Exposed | 171.5K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-06-01T00:42:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.d795a4aa4a9030021c03c1e7222fa05bde1b5dbf.001.1 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | McCook, SD; Minnehaha, SD |
| Headline | Tornado Warning issued May 31 at 7:42PM CDT until May 31 at 8:30PM CDT by NWS Sioux Falls SD |
| Expires | 2026-05-31T20:30:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| Spc ReportType | hail |
| Spc Speed | 100 |
| Spc Location | 2 WSW Humboldt |
| Spc County | Minnehaha |
| Spc State | SD |
| Spc Comments | In addition to hail up to the size of quarters... heavy rainfall was reported. (FSD) |
| MergedSources | [{"id":"spc_hail_43.63_-97.12_41","source":"spc","severity":"high","severityValue":65,"timestamp":1780273560000,"latitude":43.63,"longitude":-97.12}] |
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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