Right now
The most recent data we hold from NOAA arrived 6 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 18 May 2026 at 04:00 UTC. It is kept here as a record.
It is the 8th strongest of the 31 detections recorded within 20 km of this point since 15 March 2026. 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 17 at 10:47PM CDT until May 17 at 11:00PM CDT by NWS Omaha/Valley NE
Nearby, since 15 March 2026
- August 10, 2026 · score 22 · 18.7 km
- June 11, 2026 · score 16 · 20.4 km
- June 13, 2026 · score 22 · 25.6 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 22 out of 100, at 70 % 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) | 22 / 100 |
| Our confidence | 70% |
| Coordinates | 40.4877, -95.3011 |
| Nearest City | Bellevue (88 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-18T03:47:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.567613c0c80708d3477487b2cbe02749 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Fremont, IA; Page, IA; Atchison, MO; Holt, MO; Nodaway, MO |
| Headline | Severe Thunderstorm Warning issued May 17 at 10:47PM CDT until May 17 at 11:00PM CDT by NWS Omaha/Valley NE |
| Expires | 2026-05-17T23:00:00-05:00 |
| SenderName | NWS Omaha/Valley NE |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.567613c0c80708d3477487b2cbe02749f65e5e21.002.1","noaa_urn:oid:2.49.0.1.840.0.e804ce9784bb8cdeb4079dd51f3e3dc443b910d7.001.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 72 |
| Iem Unit | MPH |
| Iem City | 5 ESE Henderson |
| Iem County | Montgomery |
| Iem State | IA |
| Iem Wfo | OAX |
| Iem Remark | Personal Weather Station. |
| MergedSources | [{"id":"iem_G_40.180_-95.980_1779072900000","source":"iem","severity":"low","severityValue":25,"timestamp":1779072900000,"latitude":40.18,"longitude":-95.98},{"id":"iem_G_41.120_-95.350_1779070740000","source":"iem","severity":"low","severityValue":25,"timestamp":1779070740000,"latitude":41.12,"longitude":-95.35}] |
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 22/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.