This alert expired on 12 August 2026 at 04:15 UTC. It is kept here as a record.
It is the 53rd strongest of the 88 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 August 11 at 10:20PM CDT until August 11 at 11:15PM CDT by NWS Bismarck ND
An estimated 96,474 people live within 50 km of this point.
Nearby, since 15 March 2026
- June 29, 2026 · score 63 · 19.4 km
- June 30, 2026 · score 45 · 22.0 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 39 out of 100, at 89 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 39 / 100 |
| Our confidence | 89% |
| Coordinates | 46.6602, -101.0390 |
| Nearest City | Mandan (22 km) |
| Population Exposed | 96.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-12T03:20:00.000Z |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Burleigh, ND; Emmons, ND; Morton, ND; Morton, ND |
| Headline | Severe Thunderstorm Warning issued August 11 at 10:20PM CDT until August 11 at 11:15PM CDT by NWS Bismarck ND |
| Expires | 2026-08-11T23:15:00-05:00 |
| SenderName | NWS Bismarck ND |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.e0d9e518d28ce981d98bc1e7f72f8efc4176ff76.001.1","noaa_urn:oid:2.49.0.1.840.0.2728eb80f4be29035c7fb44951dd03c533dcfb1c.001.1","noaa_urn:oid:2.49.0.1.840.0.ba1f260f08ef6c88b835f0005d5f9c7f12c7a44d.001.1"] |
| Iem TypeSummary | H |
| Iem Magnitude | 2 |
| Iem Unit | Inch |
| Iem City | 9 N Flasher |
| Iem County | Morton |
| Iem State | ND |
| Iem Wfo | BIS |
| Iem Remark | Photo relayed through broadcast media. |
| MergedSources | [{"id":"iem_G_46.770_-101.340_1786503840000","source":"iem","severity":"low","severityValue":25,"timestamp":1786503840000,"latitude":46.77,"longitude":-101.34},{"id":"iem_H_46.740_-100.760_1786504140000","source":"iem","severity":"low","severityValue":25,"timestamp":1786504140000,"latitude":46.74,"longitude":-100.76},{"id":"iem_H_46.110_-100.930_1786499940000","source":"iem","severity":"low","severityValue":25,"timestamp":1786499940000,"latitude":46.11,"longitude":-100.93},{"id":"iem_H_46.590_-101.220_1786495620000","source":"iem","severity":"low","severityValue":25,"timestamp":1786495620000,"latitude":46.59,"longitude":-101.22}] |
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.
Calamity.live data shows a weather event with CalamityScore 39/100, near Mandan (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.