Right now
The most recent data we hold from NOAA arrived 4 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 20 July 2026 at 20:45 UTC. It is kept here as a record.
No stronger detection stands among the 13 recorded within 20 km of this point since 14 April 2026 — one other scored the same. Another comparable one was recorded here earlier the same day. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 20 at 3:35PM CDT until July 20 at 3:45PM CDT by NWS La Crosse WI
Urban PEI: 68,621 within a heuristic 50 km radius; not unique people.
Nearby, since 14 April 2026
- June 11, 2026 · score 16 · 16.0 km
- September 4, 2026 · 19.6 km
- September 5, 2026 · 19.6 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 39 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) | 39 / 100 |
| Legacy data-support index | 0.81/1 |
| Coordinates | 42.7522, -92.9512 |
| Nearest City | Cedar Falls (48 km) |
| Urban exposure index (PEI) | 68.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-20T20:35:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.ac99fc128e359f65ac658c5560c4589d |
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: 2026-07-20T20:35:00.000Z.
First archived: 2026-07-20T20:40:29.034Z. 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 | Floyd, IA; Black Hawk, IA; Bremer, IA; Butler, IA; Franklin, IA; Grundy, IA; Butler, IA; Cerro Gordo, IA; Franklin, IA; Grundy, IA; Hamilton, IA; Hancock, IA; Hardin, IA; Wright, IA |
| Headline | Severe Thunderstorm Warning issued July 20 at 3:35PM CDT until July 20 at 3:45PM CDT by NWS La Crosse WI |
| Expires | 2026-07-20T15:45:00-05:00 |
| SenderName | NWS La Crosse WI |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.ac99fc128e359f65ac658c5560c4589d65be9d01.001.1","noaa_urn:oid:2.49.0.1.840.0.8883fb97b2ae637d7a75a2f7cefb745a73243d50.001.1","noaa_urn:oid:2.49.0.1.840.0.575fd340dfaf85d66dba6928d0abd7fdda02106b.001.1"] |
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.
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