Glenwood Canyon weather determines interstate’s status
Transportation officials have plans to close I-70 in case of possible rain storms that could create flash flooding
Mother Nature remains in charge.
Interstate 70 through Glenwood Canyon reopened Aug. 14 after being closed for more than two weeks due to flooding and debris slides. The canyon closed briefly the next day because of fears of more flash flooding.
The Colorado Department of Transportation is now working with the Grand Junction office of the National Weather Service to keep a close eye on weather over the canyon.
Forecaster Erin Walter said that partnership is intended to keep motorists and others safe.
When forecasters spot a storm system that seems to be heading over the burn scar from 2020’s Grizzly Creek fire, they’ll issue a flash flood watch. That means weather conditions over the canyon could develop into the downpours that have closed the canyon several times this year.
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In an email from Stacia Sellers of the transportation department, she wrote that when a flash flood watch is issued, state transportation officials go into standby mode. That means having people and equipment standing by at eastbound I-70 at West Rifle, Canyon Creek and Glenwood Springs. On the westbound side of the canyon, people are stationed at Dotsero.
If storms start developing, then head toward the canyon, the Weather Service will issue a flash flood warning, meaning that conditions are ripe for flooding.
Once that warning is issued, Sellers wrote that the canyon is closed between Dotsero and Glenwood Springs. At that time, a radio channel is established and used by the Colorado State Patrol and the Hanging Lake Tunnel control center.
Once the canyon is closed, CDOT, state patrol and local law enforcement begin patrolling the canyon to make sure motorists get out safely.
At that point, highway closures are put into place on both sides of the canyon.
Hanging Lake becomes the incident command center. If those people have to evacuate, incident command is moved to Glenwood Springs.
If the canyon is closed for a short time, motorists and truckers are asked to stay put. A longer canyon closure will come with detour information. Transportation department and local authorities then put people at local detour points including Cottonwood and Independence passes.
Off the highway, the canyon’s bike path and recreation areas are closed the day before if the chance of precipitation hits 30% or more.
Walter said forecasters are still learning about the peculiarities of weather over the canyon.
“A lot of storms can be very isolated and change within a few miles,” Walter said, adding that some creek drainages are more susceptible to cloudburst activity.
A lot of forecasting right now involves how the wind moves storm cells. Walter noted that storms that form over the Flat Tops then move south.
“We’re learning the hot spots,” Walter said. “That’s the tricky part of forecasting for the mountains.”
Go to COTrip.org for the latest state highway information.