Little Belt and Highwood Mountains; Big Belt, Bridger and Castle Mountains; Elkhorn and Boulder Mountains; Gallatin Valley
Flash Flood Watch issued September 17 at 11:11AM MDT until September 20 at 12:00AM MDT by NWS Great Falls MT
Flash Flood Watch · Expires: Sep 18, 2026 12:00 UTC
Severity: Severe Urgency: Future Certainty: Possible Updated: Sep 18, 2026 07:45 UTC
Active / Indexed
Timing
- SentSep 17, 2026 17:11 UTC
- OnsetSep 19, 2026 00:00 UTC
- ExpiresSep 18, 2026 12:00 UTC
Affected areas
This advisory may be issued as multiple alerts with different affected areas. Below are the official area texts grouped into one page.