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 5 km from here.
This alert expired on 1 June 2026 at 01:45 UTC. It is kept here as a record.
No stronger detection stands among the 73 recorded within 20 km of this point since 15 March 2026 — 13 others scored the same. Another comparable one was recorded here earlier the same day. 29 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued May 31 at 8:03PM CDT until May 31 at 8:45PM CDT by NWS Sioux Falls SD
An estimated 171,544 people live within 50 km of this point.
Nearby, since 15 March 2026
- September 12, 2026 · score 37 · 9.6 km
- September 8, 2026 · score 37 · 16.4 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 67 out of 100, at 90 % 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 | 90% |
| Coordinates | 43.4570, -97.0540 |
| Nearest City | Sioux Falls (28 km) |
| Population Exposed | 171.5K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-06-01T01:03:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Tornado Warning_noaa_urn:oid:2.49.0.1.840.0.64c079aae74b47a431879698c6f6ebae |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Minnehaha, SD; Turner, SD; McCook, SD; Minnehaha, SD |
| Headline | Tornado Warning issued May 31 at 8:03PM CDT until May 31 at 8:45PM CDT by NWS Sioux Falls SD |
| Expires | 2026-05-31T20:45:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.64c079aae74b47a431879698c6f6ebae63aee451.001.1","noaa_urn:oid:2.49.0.1.840.0.d82bec5e835f1330bda429c3988801070ee15e2d.001.1","noaa_urn:oid:2.49.0.1.840.0.d795a4aa4a9030021c03c1e7222fa05bde1b5dbf.001.1"] |
| 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) |
| Iem TypeSummary | H |
| Iem Magnitude | 1 |
| Iem Unit | Inch |
| Iem City | 2 WSW Humboldt |
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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