This alert expired on 2 September 2026 at 01:30 UTC. It is kept here as a record.
No stronger detection stands among the 98 recorded within 20 km of this point since 25 May 2026 — 75 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 1 at 8:06PM CDT until September 1 at 8:30PM CDT by NWS Omaha/Valley NE
Nearby, since 25 May 2026
- June 29, 2026 · score 16 · 3.3 km
- May 25, 2026 · score 22 · 23.2 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 28 out of 100, at 71 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | high |
| Calamity Score (ours) | 28 / 100 |
| Our confidence | 71% |
| Coordinates | 42.5933, -98.0042 |
| Nearest City | Norfolk (79 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-02T01:06:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.d4b7dce7c78605d0acf0d4491419671beae1ed94.002.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Knox, NE; Holt, NE; Antelope, NE and 2 more areas |
| Headline | Severe Thunderstorm Warning issued September 1 at 8:06PM CDT until September 1 at 8:30PM CDT by NWS Omaha/Valley NE |
| Expires | 2026-09-01T20:30:00-05:00 |
| SenderName | NWS Omaha/Valley NE |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.d4b7dce7c78605d0acf0d4491419671beae1ed94.002.1","noaa_urn:oid:2.49.0.1.840.0.0e5c295cf968c6457fdb928e3a1efeed79bb414d.001.1","noaa_urn:oid:2.49.0.1.840.0.0a5247de867a96380969ccb61905a44cf6b0767c.001.1","noaa_urn:oid:2.49.0.1.840.0.c50156559e2ea7f1299b4edcc9a86557b3705264.001.1","noaa_urn:oid:2.49.0.1.840.0.ddd98b8533adeaf5eb08b0b5723c625ed3d3de71.001.1"] |
| Spc ReportType | hail |
| Spc Speed | 125 |
| Spc Location | Niobrara |
| Spc County | Knox |
| Spc State | NE |
| Spc Comments | Report of quarters with half dollars at the corner of Walnut Street and Spruce Avenue. (OAX) |
| Iem TypeSummary | G |
| Iem Magnitude | 60 |
| Iem Unit | MPH |
| Iem City | 2 S Monowi |
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 10 February 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 28/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.