This alert expired on 3 September 2026 at 16:00 UTC. It is kept here as a record.
It is the 25th strongest of the 66 detections recorded within 20 km of this point since 31 March 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 3 at 11:07AM EDT until September 3 at 12:00PM EDT by NWS Detroit/Pontiac MI
An estimated 1,844,999 people live within 50 km of this point.
Nearby, since 31 March 2026
- May 18, 2026 · score 52 · 5.5 km
- June 16, 2026 · score 52 · 6.0 km
- May 9, 2026 · score 52 · 7.6 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 46 out of 100, at 87 % 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 | 87% |
| Coordinates | 42.7294, -83.4517 |
| Nearest City | Waterford (6 km) |
| Population Exposed | 1.8M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-03T15:07:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.c8bfc0d8d9db9269ae79754e63e5cea701e3acc1.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Oakland, MI |
| Headline | Severe Thunderstorm Warning issued September 3 at 11:07AM EDT until September 3 at 12:00PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-09-03T12:00:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.c8bfc0d8d9db9269ae79754e63e5cea701e3acc1.001.1","noaa_urn:oid:2.49.0.1.840.0.eed75b986c04c75ef450114cb7bbbd9d0f65ef29.002.1","noaa_urn:oid:2.49.0.1.840.0.7af4e0257e3cd36daf5001a2bc3adffc551bb02d.002.1"] |
| Iem TypeSummary | R |
| Iem Magnitude | 1.44 |
| Iem Unit | Inch |
| Iem City | 2 NE Birmingham |
| Iem County | Oakland |
| Iem State | MI |
| Iem Wfo | DTX |
| Iem Remark | Cocorahs station MI-OK-190 Troy 3.0 WSW. The period of the Rain event was 24 hours. |
| MergedSources | [{"id":"iem_R_42.540_-83.520_1788435720000","source":"iem","severity":"low","severityValue":25,"timestamp":1788435720000,"latitude":42.54,"longitude":-83.52},{"id":"iem_R_42.610_-83.530_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.61,"longitude":-83.53},{"id":"iem_R_42.580_-83.850_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.58,"longitude":-83.85},{"id":"iem_R_42.580_-83.140_1788432540000","source":"iem","severity":"low","severityValue":25,"timestamp":1788432540000,"latitude":42.58,"longitude":-83.14},{"id":"iem_R_42.570_-83.450_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.57,"longitude":-83.45},{"id":"iem_R_42.460_-83.400_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.46,"longitude":-83.4},{"id":"iem_R_42.450_-83.360_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.45,"longitude":-83.36},{"id":"iem_R_42.520_-83.220_1788436800000","source":"iem","severity":"low","severityValue":25,"timestamp":1788436800000,"latitude":42.52,"longitude":-83.22},{"id":"iem_R_42.420_-83.340_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.42,"longitude":-83.34},{"id":"iem_R_42.580_-83.250_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.58,"longitude":-83.25},{"id":"iem_R_42.690_-83.550_1788430500000","source":"iem","severity":"low","severityValue":25,"timestamp":1788430500000,"latitude":42.69,"longitude":-83.55},{"id":"iem_R_42.470_-83.370_1788435000000","source":"iem","severity":"low","severityValue":25,"timestamp":1788435000000,"latitude":42.47,"longitude":-83.37},{"id":"iem_R_42.530_-83.150_1788431700000","source":"iem","severity":"low","severityValue":25,"timestamp":1788431700000,"latitude":42.53,"longitude":-83.15},{"id":"iem_R_42.650_-83.400_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.65,"longitude":-83.4},{"id":"iem_R_42.430_-83.380_1788435900000","source":"iem","severity":"low","severityValue":25,"timestamp":1788435900000,"latitude":42.43,"longitude":-83.38},{"id":"iem_R_42.560_-83.200_1788433200000","source":"iem","severity":"low","severityValue":25,"timestamp":1788433200000,"latitude":42.56,"longitude":-83.2}] |
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 Waterford?
Calamity.live data shows a weather event with CalamityScore 46/100, near Waterford (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.