This alert expired on 18 May 2026 at 21:15 UTC. It is kept here as a record.
No stronger detection stands among the 23 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. 5 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 18 at 4:40PM EDT until May 18 at 5:15PM EDT by NWS Detroit/Pontiac MI
An estimated 1,335,704 people live within 50 km of this point.
How we know
Confirmed by 6 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 89 % 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) | 52 / 100 |
| Our confidence | 89% |
| Coordinates | 42.2837, -83.6714 |
| Nearest City | Ann Arbor (6 km) |
| Population Exposed | 1.3M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T20:40:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.90f0b274cd18b4b7ac39eaed223c85fc |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Tuscola, MI; Washtenaw, MI; Livingston, MI and 7 more areas |
| Headline | Severe Thunderstorm Warning issued May 18 at 4:40PM EDT until May 18 at 5:15PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-05-18T17:15:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| MergedCount | 10 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.90f0b274cd18b4b7ac39eaed223c85fc28f82537.001.1","noaa_urn:oid:2.49.0.1.840.0.bb37b469d4e8376236e2e1fd0a00f0cc705e46e6.001.1","noaa_urn:oid:2.49.0.1.840.0.b87ade078e0907622c98b46b088ef4cbced654ea.001.1","noaa_urn:oid:2.49.0.1.840.0.e5f00ad9cb800b231a0dba49a2bb9237fac78436.001.1","noaa_urn:oid:2.49.0.1.840.0.24639ea2e53c9ffab7b3a03a64bb5d5e941bdb02.001.1","noaa_urn:oid:2.49.0.1.840.0.dede36097957833f88d16daaa336532f07c18f58.001.1","noaa_urn:oid:2.49.0.1.840.0.5f4d4f06aebdd09c46d818307e6968851f070515.001.1","noaa_urn:oid:2.49.0.1.840.0.10de0c1a013f30bb49b91a42b73f0c72c5cd6d17.001.1","noaa_urn:oid:2.49.0.1.840.0.b31e30af91ca74566c18b6adf99648f350d15666.001.1","noaa_urn:oid:2.49.0.1.840.0.92eb96f86063a3bea059f59dfc303939f65bcd0c.001.1"] |
| Google News RssFeed | weather |
| Google News SourceName | ClickOnDetroit | WDIV Local 4 |
| MergedSources | [{"id":"gnews_weather_494202_148","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779130324000,"latitude":42.33,"longitude":-83.05},{"id":"gnews_weather_494203_153","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779131397000,"latitude":42.33,"longitude":-83.05},{"id":"gnews_weather_494203_158","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779133500000,"latitude":42.33,"longitude":-83.05},{"id":"gnews_weather_494201_166","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779124382000,"latitude":42.33,"longitude":-83.05},{"id":"gnews_weather_494201_169","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779124179000,"latitude":42.33,"longitude":-83.05}] |
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.
Calamity.live data shows a weather event with CalamityScore 52/100, near Ann Arbor (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.