Flood in Glacier County, Montana

Late morning June 29 reports were received that water in Swiftcurrent Lake was approaching the bottom of the bridge connecting Many Glacier Hotel to Many Glacier Road, and that several trails and campsites had already been closed in the Many Glacier Valley due to flooding from heavy rain and a small contribution from snowmelt. Many Glacier Hotel was ultimately evacuated after MBRFC forecast crest information was received. Numerous trails were closed in the Many Glacier Valley, with it being noted that water was flowing down several trails.

Large scale upper level troughing with two separate embedded upper level lows progressed across the region late June. The colder core, which actually ended up being the southern of the two, moved across Southwest Montana and resulted in snow levels falling to below 6,000ft at times as heaviest precipitation moved over the area. Heavy snow developed near and above pass level in northwest Beaverhead County, resulting in nearly 2 feet of snow near the peaks close to the ID border.

Meanwhile further north under the second upper low, a strong surface low ended up developing near the Hi-Line, which resulted in strong winds in a few zones before the surface low filled/weakened.

Strong upper level support further north resulted in widespread heavy rains, with additional upslope forcing along the Rocky Mountain Front, which resulted in some flooding in Glacier NP June 29.