Right now
The most recent data we hold from NOAA arrived 9 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 13 May 2026 at 21:30 UTC. It is kept here as a record.
It is the 3rd strongest of the 6 detections recorded within 20 km of this point since 13 May 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 13 at 3:06PM MDT until May 13 at 3:30PM MDT by NWS Great Falls MT
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 22 out of 100, at 70 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 22 / 100 |
| Our confidence | 70% |
| Coordinates | 46.9011, -111.2606 |
| Nearest City | Great Falls (67 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-13T21:06:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.90101766f236461d215e9618823dd8a0 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Chouteau, MT; Fergus, MT; Judith Basin, MT; Cascade, MT; Chouteau, MT; Teton, MT; Broadwater, MT; Jefferson, MT |
| Headline | Severe Thunderstorm Warning issued May 13 at 3:06PM MDT until May 13 at 3:30PM MDT by NWS Great Falls MT |
| Expires | 2026-05-13T15:30:00-06:00 |
| SenderName | NWS Great Falls MT |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.90101766f236461d215e9618823dd8a06868896e.002.1","noaa_urn:oid:2.49.0.1.840.0.7b95f41cdc49cf2dfdc53a50e722f7827022f1bf.001.1","noaa_urn:oid:2.49.0.1.840.0.d5320ccd43234b690def9b02b937d698e7aa634c.001.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 61 |
| Iem Unit | MPH |
| Iem City | 1 ESE Malmstrom Afb |
| Iem County | Cascade |
| Iem State | MT |
| Iem Wfo | TFX |
| Iem Remark | AWOS station KGFA Malmstrom AFB. |
| MergedSources | [{"id":"iem_G_47.470_-111.380_1778705760000","source":"iem","severity":"low","severityValue":25,"timestamp":1778705760000,"latitude":47.47,"longitude":-111.38},{"id":"iem_G_47.320_-111.470_1778705220000","source":"iem","severity":"low","severityValue":25,"timestamp":1778705220000,"latitude":47.32,"longitude":-111.47},{"id":"iem_G_47.280_-110.800_1778705700000","source":"iem","severity":"low","severityValue":25,"timestamp":1778705700000,"latitude":47.28,"longitude":-110.8},{"id":"iem_G_47.500_-111.170_1778706060000","source":"iem","severity":"low","severityValue":25,"timestamp":1778706060000,"latitude":47.5,"longitude":-111.17}] |
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.
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