This alert expired on 3 September 2026 at 04:00 UTC. It is kept here as a record.
It is the 23rd strongest of the 39 detections recorded within 20 km of this point since 13 March 2026. The last comparable one was on 2 September 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 2 at 10:47PM EDT until September 3 at 12:00AM EDT by NWS Detroit/Pontiac MI
An estimated 3,226,485 people live within 50 km of this point.
Nearby, since 13 March 2026
- July 3, 2026 · score 52 · 5.2 km
- June 11, 2026 · score 46 · 6.0 km
- April 4, 2026 · score 52 · 8.9 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 46 out of 100, at 86 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 46 / 100 |
| Our confidence | 86% |
| Coordinates | 42.4290, -83.4552 |
| Nearest City | Novi (6 km) |
| Population Exposed | 3.2M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-03T02:47:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.80321a7d8f44f394ae80b7122b51eb393006f425.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Washtenaw, MI; Wayne, MI; Livingston, MI; Oakland, MI |
| Headline | Severe Thunderstorm Warning issued September 2 at 10:47PM EDT until September 3 at 12:00AM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-09-03T00:00:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.80321a7d8f44f394ae80b7122b51eb393006f425.001.1","noaa_urn:oid:2.49.0.1.840.0.eb1104a496506cbb683103101049a9722cbc4a07.001.1"] |
| Iem TypeSummary | H |
| Iem Magnitude | 1 |
| Iem Unit | Inch |
| Iem City | Williamston |
| Iem County | Ingham |
| Iem State | MI |
| Iem Wfo | GRR |
| Iem Remark | Relayed through Ingham Co Emergency Management. |
| MergedSources | [{"id":"iem_H_42.690_-84.280_1788402720000","source":"iem","severity":"low","severityValue":25,"timestamp":1788402720000,"latitude":42.69,"longitude":-84.28}] |
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 near Novi?
Calamity.live data shows a weather event with CalamityScore 46/100, near Novi (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.