This alert expired on 4 September 2026 at 00:31 UTC. It is kept here as a record.
It is the 3rd strongest of the 65 detections recorded within 20 km of this point since 15 March 2026. The last comparable one was on 29 August 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 3 at 7:21PM CDT until September 3 at 7:30PM CDT by NWS Grand Forks ND
An estimated 194,125 people live within 50 km of this point.
Nearby, since 15 March 2026
- June 30, 2026 · score 67 · 5.9 km
- June 19, 2026 · score 43 · 12.4 km
- June 29, 2026 · score 43 · 14.0 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 49 out of 100, at 91 % 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 | High |
| Calamity Score (ours) | 49 / 100 |
| Our confidence | 91% |
| Coordinates | 46.8649, -96.3760 |
| Nearest City | Moorhead (30 km) |
| Population Exposed | 194.1K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-09-04T00:21:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.fb0651f8d1256ea12f3744ad232ae2db1b4cc1f2.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Otter Tail, MN; Wilkin, MN; Marshall, MN; Pennington, MN; Polk, MN; Red Lake, MN |
| Headline | Severe Thunderstorm Warning issued September 3 at 7:21PM CDT until September 3 at 7:30PM CDT by NWS Grand Forks ND |
| Expires | 2026-09-03T19:31:00-05:00 |
| SenderName | NWS Grand Forks ND |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.fb0651f8d1256ea12f3744ad232ae2db1b4cc1f2.001.1","noaa_urn:oid:2.49.0.1.840.0.758646c7a6f515ea0536cf79a8c0f0b0533e8145.001.1","noaa_urn:oid:2.49.0.1.840.0.f164a9a5f8852aae9e71d79c1fb855f4bdd633da.001.1"] |
| Spc ReportType | hail |
| Spc Speed | 230 |
| Spc Location | 6 S Naytahwaush |
| Spc County | Mahnomen |
| Spc State | MN |
| Spc Comments | Broadcast media shared photo of hail stone estimated to be 2 to 2.5 inches in diameter near Tulaby Lake MN. Time estimated from radar. (FGF) |
| Iem TypeSummary | G |
| Iem Magnitude | 59 |
| Iem Unit | MPH |
| Iem City | 4 WSW Felton |
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 near Moorhead?
Calamity.live data shows a weather event with CalamityScore 49/100, near Moorhead (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.