This alert expired on 17 May 2026 at 17:00 UTC. It is kept here as a record.
No stronger detection stands among the 40 recorded within 20 km of this point since 16 March 2026 — 2 others scored the same. 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: Tornado Warning issued May 17 at 11:16AM CDT until May 17 at 12:00PM CDT by NWS Milwaukee/Sullivan WI
An estimated 428,294 people live within 50 km of this point.
Nearby, since 16 March 2026
- June 18, 2026 · score 43 · 11.7 km
- June 24, 2026 · score 67 · 16.8 km
- June 10, 2026 · score 43 · 19.2 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 67 out of 100, at 81 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | critical |
| Calamity Score (ours) | 67 / 100 |
| Our confidence | 81% |
| Coordinates | 42.7800, -89.4950 |
| Nearest City | Fitchburg (20 km) |
| Population Exposed | 428.3K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-05-17T16:16:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Tornado Warning_noaa_urn:oid:2.49.0.1.840.0.937542335478255db2159856c49b6a9f |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Dane, WI; Green, WI |
| Headline | Tornado Warning issued May 17 at 11:16AM CDT until May 17 at 12:00PM CDT by NWS Milwaukee/Sullivan WI |
| Expires | 2026-05-17T12:00:00-05:00 |
| SenderName | NWS Milwaukee/Sullivan WI |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.937542335478255db2159856c49b6a9f2d0863ec.001.1","noaa_urn:oid:2.49.0.1.840.0.ad80f2f5317158f87bdff2320286f5959abf53a8.001.1"] |
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 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 near Fitchburg?
Calamity.live data shows a weather event with CalamityScore 67/100, near Fitchburg (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.