Strong snowstorm, avalanche risk will close parts of Idaho 21. Where it’s closed
The Idaho Transportation Department will close parts of Idaho 21 at 6 p.m. on Thursday as a significant winter storm plows through Idaho.
Over half-a-foot of snow is forecast to drop in Lowman, according to the National Weather Service, while 12 to 18 inches is expected in Stanley. Other areas of the Boise Mountains, such as Ketchum, could receive up to 2 feet of snow.
The highway will be closed north and south of Lowman, from milepost 93.7 to 105.5 (Grandjean to Banner Summit) north of Lowman, and from 70 to milepost 48 near Idaho City to the south.
“This storm could deliver up to 2 feet of fresh snow, and with wind gusts near 25 miles per hour,” Eric Copeland, field operations manager for the Idaho Transportation Department, said in a news release. “We are expecting next to no visibility and drifting, making it too dangerous to travel.”
ITD expects the highway sections to reopen sometime on Saturday, based on current weather forecasts.
An avalanche risk was also issued for the section of Idaho 21 between Grandjean and Banner Summit. The Sawtooth Avalanche Center warned that the avalanche risk would rise after dark, and avalanche warnings would likely be issued.
An AVALANCHE WATCH is in effect. The avalanche danger will rise dramatically after dark, and AVALANCHE WARNINGS are likely to be issued. The danger may reach EXTREME in the Soldier & Wood River Valley Mtns by tomorrow. pic.twitter.com/ZyfV0KuBHT
— Sawtooth Avalanche Center (@SawtoothAvy) March 9, 2023
Parts of the mountains around Idaho 21, between Idaho City and Lowman, already have a snow depth of 5 to 8 feet, according to the U.S. Forest Service, before the upcoming storm.
