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 16 May 2026 at 02:30 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 16 March 2026. The last comparable one was on 14 April 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 15 at 9:04PM CDT until May 15 at 9:30PM CDT by NWS La Crosse WI
An estimated 27,366 people live within 50 km of this point.
Nearby, since 16 March 2026
- August 7, 2026 · score 34 · 13.9 km
- July 2, 2026 · score 34 · 17.9 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 34 out of 100, at 90 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 34 / 100 |
| Our confidence | 90% |
| Coordinates | 43.0520, -92.6140 |
| Nearest City | Mason City (49 km) |
| Population Exposed | 27.4K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-16T02:04:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.3b3cdf0c90f107b81a8f587eec90095619cb0e30.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Chickasaw, IA; Floyd, IA |
| Headline | Severe Thunderstorm Warning issued May 15 at 9:04PM CDT until May 15 at 9:30PM CDT by NWS La Crosse WI |
| Expires | 2026-05-15T21:30:00-05:00 |
| SenderName | NWS La Crosse WI |
| HasExactCoords | true |
| Iem TypeSummary | H |
| Iem Magnitude | 1 |
| Iem Unit | Inch |
| Iem City | 2 WNW Meservey |
| Iem County | Hancock |
| Iem State | IA |
| Iem Wfo | DMX |
| MergedSources | [{"id":"iem_H_42.920_-93.500_1778893500000","source":"iem","severity":"low","severityValue":25,"timestamp":1778893500000,"latitude":42.92,"longitude":-93.5},{"id":"iem_H_43.140_-93.380_1778892420000","source":"iem","severity":"low","severityValue":25,"timestamp":1778892420000,"latitude":43.14,"longitude":-93.38},{"id":"iem_H_43.030_-93.340_1778893200000","source":"iem","severity":"low","severityValue":25,"timestamp":1778893200000,"latitude":43.03,"longitude":-93.34},{"id":"iem_H_42.920_-93.500_1778893380000","source":"iem","severity":"low","severityValue":25,"timestamp":1778893380000,"latitude":42.92,"longitude":-93.5}] |
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 in this area?
Calamity.live data shows a weather event with CalamityScore 34/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.