This alert expired on 4 September 2026 at 01:33 UTC. It is kept here as a record.
No stronger detection stands among the 48 recorded within 20 km of this point since 15 March 2026 — 3 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Tornado Warning issued September 3 at 8:23PM CDT until September 3 at 8:30PM CDT by NWS Grand Forks ND
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 46 out of 100, at 71 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Critical |
| Calamity Score (ours) | 46 / 100 |
| Our confidence | 71% |
| Coordinates | 46.1450, -95.8337 |
| Nearest City | Moorhead (108 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-04T01:23:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.2720bbf89cd657ceba2e37c2595b5cd58ef4b03e.001.1 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Grant, MN; Otter Tail, MN |
| Headline | Tornado Warning issued September 3 at 8:23PM CDT until September 3 at 8:30PM CDT by NWS Grand Forks ND |
| Expires | 2026-09-03T20:33:00-05:00 |
| SenderName | NWS Grand Forks ND |
| HasExactCoords | true |
| Spc ReportType | hail |
| Spc Speed | 100 |
| Spc Location | Fergus Falls |
| Spc County | Otter Tail |
| Spc State | MN |
| Spc Comments | (FGF) |
| Iem TypeSummary | H |
| Iem Magnitude | 1 |
| Iem Unit | Inch |
| Iem City | Fergus Falls |
| Iem County | Otter Tail |
| Iem State | MN |
Safety Information
If a tornado warning is issued: go to a basement or an interior room on the lowest floor, away from windows. A vehicle and a mobile home are not shelter. Cover your head and neck. Wait for the official all-clear before going outside, and watch for downed power lines and gas leaks afterwards.
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 46/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.