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🟡 Moderate
Dense Fog Advisory
Helena Valley; Canyon Ferry Area; Missouri Headwaters; Gallatin Valley; Beaverhead and Western Madison below 6000ft
Dense Fog Advisory issued November 1 at 12:57AM MDT until November 1 at 12:00PM MST by NWS Great Falls MT
Alert Description
* WHAT...Variable visibility down to one quarter of a mile or less in dense fog. * WHERE...Canyon Ferry Area, Helena Valley, Beaverhead and Western Madison below 6000ft, Gallatin Valley, and Missouri Headwaters. * WHEN...Until noon MST today. * IMPACTS...Low visibility could make driving conditions hazardous.
Safety Instructions
If driving, slow down, use your headlights, and leave plenty of distance ahead of you.
Time Information
Effective
Nov 1, 2026, 6:57 AM
Expires
Nov 1, 2026, 7:00 PM
Issued
Nov 1, 2026, 6:57 AM
Alert Details
Severity
Moderate
Urgency
Expected
Certainty
Likely
Category
Met
Issued By
NWS Great Falls MT
National Weather Service