Reported by SPC today.
It is the 10th strongest of the 34 detections recorded within 20 km of this point since 17 May 2026. Another comparable one was recorded here earlier the same day.
What the source measured
SPC reported: Wind 60 kt near 10 SSE Alcester, Union, SD. Wind measured by anemometer. (FSD)
An estimated 82,821 people live within 50 km of this point.
Nearby, since 17 May 2026
- June 1, 2026 · score 46 · 16.5 km
How we know
Confirmed by 2 independent sources, including SPC.
Our own score for this event is 32 out of 100, at 86 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 32 / 100 |
| Our confidence | 86% |
| Coordinates | 42.8900, -96.5400 |
| Nearest City | Sioux City (45 km) |
| Population Exposed | 82.8K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-02T02:30:00.000Z |
| Source | https://www.spc.noaa.gov/climo/reports/today.html |
Score Breakdown
Technical Details
| ReportType | wind |
| Speed | 60 |
| Location | 10 SSE Alcester |
| County | Union |
| State | SD |
| Comments | Wind measured by anemometer. (FSD) |
| Iem TypeSummary | G |
| Iem Magnitude | 60 |
| Iem Unit | MPH |
| Iem City | 10 SSE Alcester |
| Iem County | Union |
| Iem State | SD |
| Iem Wfo | FSD |
| Iem Remark | Wind measured by anemometer. |
| MergedSources | [{"id":"iem_G_42.890_-96.540_1788316200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788316200000,"latitude":42.89,"longitude":-96.54}] |
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 10 February 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 32/100 (United States), based on data from spc. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.