Right now
The most recent data we hold from NOAA arrived 69 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 17 May 2026 at 21:45 UTC. It is kept here as a record.
It is the 19th strongest of the 67 detections recorded within 20 km of this point since 17 May 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 17 at 3:59PM CDT until May 17 at 4:45PM CDT by NWS Sioux Falls SD
An estimated 171,544 people live within 50 km of this point.
Nearby, since 17 May 2026
- June 1, 2026 · score 67 · 17.6 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 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 | Medium |
| Calamity Score (ours) | 43 / 100 |
| Our confidence | 79% |
| Coordinates | 43.1815, -97.0436 |
| Nearest City | Sioux Falls (47 km) |
| Population Exposed | 171.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-17T20:59:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.94aba1914d4614b920675d780456258f |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Lincoln, SD; Turner, SD; Bon Homme, SD; Clay, SD; Hutchinson, SD; Turner, SD; Yankton, SD |
| Headline | Severe Thunderstorm Warning issued May 17 at 3:59PM CDT until May 17 at 4:45PM CDT by NWS Sioux Falls SD |
| Expires | 2026-05-17T16:45:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.94aba1914d4614b920675d780456258fcd017857.001.1","noaa_urn:oid:2.49.0.1.840.0.3628ce42a0e60dd6a598ed96acd7d7e92ab54ec7.001.1"] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
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.