Right now
The most recent data we hold from NOAA arrived 3 minutes 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 21 July 2026 at 02:00 UTC. It is kept here as a record.
It is the 3rd strongest of the 27 detections recorded within 20 km of this point since 10 March 2026. The last comparable one was on 13 June 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 20 at 8:21PM CDT until July 20 at 9:00PM CDT by NWS Des Moines IA
Urban PEI: 24,624 within a heuristic 50 km radius; not unique people.
Nearby, since 10 March 2026
- July 21, 2026 · score 28 · 0.8 km
- March 11, 2026 · score 40 · 7.9 km
- March 10, 2026 · score 40 · 10.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 28 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) | 28 / 100 |
| Legacy data-support index | 0.80/1 |
| Coordinates | 40.9435, -92.4129 |
| Nearest City | Ottumwa (9 km) |
| Urban exposure index (PEI) | 24.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-21T01:21:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.76dac2bf11e0af701b3c572b18982e62 |
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: 2026-07-21T01:21:00.000Z.
First archived: 2026-07-21T01:24:41.736Z. 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 | Lucas, IA; Mahaska, IA; Marion, IA; Monroe, IA; Hancock, IL; McDonough, IL; Lee, IA; Marion, IA |
| Headline | Severe Thunderstorm Warning issued July 20 at 8:21PM CDT until July 20 at 9:00PM CDT by NWS Des Moines IA |
| Expires | 2026-07-20T21:00:00-05:00 |
| SenderName | NWS Des Moines IA |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.76dac2bf11e0af701b3c572b18982e626a5dbf8e.001.1","noaa_urn:oid:2.49.0.1.840.0.0b08eb7fa919937c924a6b66e658419982b61bea.001.1","noaa_urn:oid:2.49.0.1.840.0.7813c65167abe9802cde105b23ee4f7adf02fc27.002.1"] |
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 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.
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