This alert expired on 16 May 2026 at 07:00 UTC. It is kept here as a record.
It is the 3rd strongest of the 33 detections recorded within 20 km of this point since 3 April 2026. The last comparable one was on 18 April 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 16 at 1:06AM CDT until May 16 at 2:00AM CDT by NWS Milwaukee/Sullivan WI
An estimated 484,478 people live within 50 km of this point.
Nearby, since 3 April 2026
- June 10, 2026 · score 43 · 11.0 km
- July 2, 2026 · score 43 · 12.8 km
- June 10, 2026 · score 43 · 16.7 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 81 % 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) | 43 / 100 |
| Our confidence | 81% |
| Coordinates | 42.8729, -89.0739 |
| Nearest City | Janesville (22 km) |
| Population Exposed | 484.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-16T06:06:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.c42aff1eede7da7619cbaa8dc53a5858 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Jefferson, WI; Rock, WI; Walworth, WI; Dane, WI; Green, WI; Rock, WI |
| Headline | Severe Thunderstorm Warning issued May 16 at 1:06AM CDT until May 16 at 2:00AM CDT by NWS Milwaukee/Sullivan WI |
| Expires | 2026-05-16T02:00:00-05:00 |
| SenderName | NWS Milwaukee/Sullivan WI |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.c42aff1eede7da7619cbaa8dc53a58584036d052.001.1","noaa_urn:oid:2.49.0.1.840.0.7710d31eadb682a6402ff99df4a96ffaad496e8d.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 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 Janesville?
Calamity.live data shows a weather event with CalamityScore 43/100, near Janesville (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.