Right now
The most recent data we hold from NOAA arrived 7 hours ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 9 August 2026 at 21:00 UTC. It is kept here as a record.
No stronger detection stands among the 26 recorded within 20 km of this point since 4 April 2026 — 8 others scored the same. Another comparable one was recorded here earlier the same day. 8 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 9 at 4:36PM EDT until August 9 at 5:00PM EDT by NWS Grand Rapids MI
Urban PEI: 154,683 within a heuristic 50 km radius; not unique people.
Nearby, since 4 April 2026
- August 10, 2026 · score 43 · 1.7 km
- August 9, 2026 · score 43 · 15.3 km
- July 3, 2026 · score 43 · 18.8 km
How we know
4 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 43 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 43 / 100 |
| Legacy data-support index | 0.90/1 |
| Coordinates | 42.1663, -86.1487 |
| Nearest City | Granger (46 km) |
| Urban exposure index (PEI) | 154.7K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-09T20:36:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.bb7e4ca76f71678907dd5fd0a5bad776 |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-08-09T20:36:00.000Z.
First archived: 2026-08-09T20:41:41.189Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Barry, MI; Kent, MI; Kalamazoo, MI; Allegan, MI and 3 more areas |
| Headline | Severe Thunderstorm Warning issued August 9 at 4:36PM EDT until August 9 at 5:00PM EDT by NWS Grand Rapids MI |
| Expires | 2026-08-09T17:00:00-04:00 |
| SenderName | NWS Grand Rapids MI |
| HasExactCoords | true |
| MergedCount | 6 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.bb7e4ca76f71678907dd5fd0a5bad776ef97e27b.001.1","noaa_urn:oid:2.49.0.1.840.0.7e3318125e31f525a712373aa61cbc2edbfcef50.001.1","noaa_urn:oid:2.49.0.1.840.0.0fcee232a2561f94e8f74db1124217f1e7d3af81.001.1","noaa_urn:oid:2.49.0.1.840.0.a42698f929261cc8c32165921eb7e7162a96f3b4.001.1","noaa_urn:oid:2.49.0.1.840.0.816a19719e98ee8be204c0b8e604902719212284.001.1","noaa_urn:oid:2.49.0.1.840.0.afee4faae08e0e9a9c1193fa3191514b05e6c587.001.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 31 |
| Iem Unit | MPH |
| Iem City | Macatawa |
| Iem County | Ottawa |
| Iem State | MI |
| Iem Wfo | GRR |
| Iem Remark | Buoy station HLNM4 Holland Harbor. |
| MergedSources | [{"id":"iem_D_42.660_-86.190_1786303200000","source":"iem","severity":"low","severityValue":25,"timestamp":1786303200000,"latitude":42.66,"longitude":-86.19},{"id":"iem_M_42.680_-86.220_1786303080000","source":"iem","severity":"low","severityValue":25,"timestamp":1786303080000,"latitude":42.68,"longitude":-86.22},{"id":"iem_G_42.770_-86.200_1786303440000","source":"iem","severity":"low","severityValue":25,"timestamp":1786303440000,"latitude":42.77,"longitude":-86.2}] |
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.
Review the area, threshold and delivery channel in your account.
Want to know when something happens in this area?