Right now
The most recent data we hold from NOAA arrived 73 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 7 September 2026 at 01:15 UTC. It is kept here as a record.
No stronger detection stands among the 17 recorded within 20 km of this point since 14 May 2026 — 4 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Tornado Warning issued September 6 at 8:06PM CDT until September 6 at 8:15PM CDT by NWS Bismarck ND
How we know
3 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 46 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
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 |
| Legacy data-support index | 0.70/1 |
| Coordinates | 47.6100, -102.9660 |
| Nearest City | Williston (77 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-09-07T01:06:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.d33a768bb60b6ca417c6a29c0fd900b3941179d3.001.1 |
Physical priority index · v4 (historical). Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-09-07T01:06:00.000Z.
First archived: 2026-09-07T01:12:19.685Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Dunn, ND; McKenzie, ND |
| Headline | Tornado Warning issued September 6 at 8:06PM CDT until September 6 at 8:15PM CDT by NWS Bismarck ND |
| Expires | 2026-09-06T20:15:00-05:00 |
| SenderName | NWS Bismarck ND |
| HasExactCoords | true |
| Spc ReportType | hail |
| Spc Speed | 175 |
| Spc Location | 5 S Watford City |
| Spc County | McKenzie |
| Spc State | ND |
| Spc Comments | Report from mPING: Golf Ball (1.75 in.). (BIS) |
| Iem TypeSummary | T |
| Iem City | 8 SSW Arnegard |
| Iem County | McKenzie |
| Iem State | ND |
| Iem Wfo | BIS |
| Iem Remark | Storm chaser reported brief touchdown. Radar estimated location. |
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.
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