Right now
The most recent data we hold from NOAA arrived 5 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 1 June 2026 at 02:15 UTC. It is kept here as a record.
No stronger detection stands among the 95 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. 36 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued May 31 at 8:55PM CDT until May 31 at 9:15PM CDT by NWS Sioux Falls SD
Urban PEI: 171,544 within a heuristic 50 km radius; not unique people.
Nearby, since 15 March 2026
- September 12, 2026 · score 37 · 18.4 km
- June 1, 2026 · score 67 · 19.2 km
- May 25, 2026 · score 43 · 20.8 km
How we know
8 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 67 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
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 |
| Legacy data-support index | 0.89/1 |
| Coordinates | 43.3630, -96.8550 |
| Nearest City | Sioux Falls (22 km) |
| Urban exposure index (PEI) | 171.5K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-06-01T01:55:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Tornado Warning_noaa_urn:oid:2.49.0.1.840.0.749a4c468efb0b67930cde3c83bb83b6 |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-06-01T01:55:00.000Z.
First archived: 2026-06-01T01:57:48.634Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Lincoln, SD; Turner, SD; Minnehaha, SD |
| Headline | Tornado Warning issued May 31 at 8:55PM CDT until May 31 at 9:15PM CDT by NWS Sioux Falls SD |
| Expires | 2026-05-31T21:15:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.749a4c468efb0b67930cde3c83bb83b64bf2603e.001.1","noaa_urn:oid:2.49.0.1.840.0.9a74cf00938af3f4c339a692743eafdc9d3814c4.001.1"] |
| Iem TypeSummary | T |
| Iem City | 1 NW Bridgewater |
| Iem County | McCook |
| Iem State | SD |
| Iem Wfo | FSD |
| Iem Remark | Tornado is kicking up dust from the ground now. |
| MergedSources | [{"id":"iem_C_43.570_-97.500_1780268400000","source":"iem","severity":"low","severityValue":25,"timestamp":1780268400000,"latitude":43.57,"longitude":-97.5},{"id":"iem_H_43.630_-97.640_1780263300000","source":"iem","severity":"low","severityValue":25,"timestamp":1780263300000,"latitude":43.63,"longitude":-97.64},{"id":"iem_T_43.530_-97.030_1780276260000","source":"iem","severity":"low","severityValue":25,"timestamp":1780276260000,"latitude":43.53,"longitude":-97.03},{"id":"iem_H_43.630_-97.120_1780273560000","source":"iem","severity":"low","severityValue":25,"timestamp":1780273560000,"latitude":43.63,"longitude":-97.12},{"id":"iem_H_43.600_-97.630_1780266600000","source":"iem","severity":"low","severityValue":25,"timestamp":1780266600000,"latitude":43.6,"longitude":-97.63},{"id":"iem_R_43.600_-97.620_1780273380000","source":"iem","severity":"low","severityValue":25,"timestamp":1780273380000,"latitude":43.6,"longitude":-97.62},{"id":"iem_T_43.560_-97.520_1780268820000","source":"iem","severity":"low","severityValue":25,"timestamp":1780268820000,"latitude":43.56,"longitude":-97.52}] |
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.
Review the area, threshold and delivery channel in your account.
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