Calamity
MediumSevere WeatherCalamity Score: 22

Severe Weather in United States

ChouteauUnited StatesNOAA

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 22:15 UTC. It is kept here as a record.

No stronger detection stands among the 5 recorded within 20 km of this point since 13 May 2026 — one other scored the same.

What the source measured

NOAA reported: Severe Thunderstorm Warning issued May 13 at 3:28PM MDT until May 13 at 4:15PM MDT by NWS Great Falls MT

How we know

Confirmed by 4 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

TypeSevere Weather
SeverityMedium
Calamity Score (ours)22 / 100
Our confidence70%
Coordinates47.6150, -110.2010
Nearest CityGreat Falls (83 km)
Impact Tierminor
Timestamp2026-05-13T21:28:00.000Z
Sourcehttps://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.5d38e788abc82051fe260586de029a53acafb901.001.1

Score Breakdown

35
intensity
0
population
0
cascading
80
historical

Technical Details

EventSevere Thunderstorm Warning
UrgencyImmediate
CertaintyObserved
AreaDescBlaine, MT; Cascade, MT; Chouteau, MT; Fergus, MT; Hill, MT; Judith Basin, MT; Liberty, MT
HeadlineSevere Thunderstorm Warning issued May 13 at 3:28PM MDT until May 13 at 4:15PM MDT by NWS Great Falls MT
Expires2026-05-13T16:15:00-06:00
SenderNameNWS Great Falls MT
HasExactCoordstrue
Iem TypeSummaryG
Iem Magnitude61
Iem UnitMPH
Iem City1 ESE Malmstrom Afb
Iem CountyCascade
Iem StateMT
Iem WfoTFX
Iem RemarkAWOS station KGFA Malmstrom AFB.
MergedSources[{"id":"iem_G_47.250_-110.480_1778706000000","source":"iem","severity":"low","severityValue":25,"timestamp":1778706000000,"latitude":47.25,"longitude":-110.48},{"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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