Interstate 70 remained closed in both directions via Glenwood Canyon on Thursday due to a flash flood warning issued by the National Weather Service and rapid changes in the weather, the Colorado Department of Transportation said.
The highway between Dotesro and Glenwood Springs was closed at 4:20 p.m. Wednesday for a flash flood warning, and remained closed while flash flood watch is in place “out of caution,” the department said.
The Grizzly Creek burn scar experienced “significant rainfall” Wednesday evening, although no new mudslides or damage were reported, the department said, adding that a new mudslide in the canyon could result in an extended highway closure.
Several rain gauges measured more than 1 inch of rain, the National Weather Service said, with between a quarter and a half inch of that precipitation occurring on Thursday.
Due to rapid changes in weather conditions and high uncertainty in the forecast, the highway remained closed as flash flood monitoring in place could quickly turn into a flash flood warning.
Thursday’s rains, however, were consistent throughout the day and did not reach the high hourly rainfall rates that typically cause flooding and mudslides, although they were enough to saturate the soil, National Weather Service meteorologist Matthew Aleksa said.
The state Department of Transportation has closed the canyon when a flash flood warning is issued.
The recent repairs “withstood” the most recent storms, the department said.
Crews worked on pavement repairs over the past week after flooding, mudslides and debris flows destroyed parts of the intestate during heavy rains over the past month.
On Thursday, the state’s transportation department said crews were to wait at closure points 24 hours a day until Friday morning, when flash flood monitoring is expected to expire.
Once the watch has expired, the threat of rain for the weekend will likely give way to warm air from the west, although there is a risk of showers and isolated storms, Aleksa said. .
“It appears that the widespread nature of the humidity and precipitation seems fairly minimal as the drier air moves westward and continues to do so throughout the weekend,” he said. “It looks like today is truly the last big day for the threat of heavy rains.”
The highway in the canyon was closed for more than two weeks starting July 29. It reopened on Saturday to one lane in each direction.
The agency recommends that drivers use the north detour around the closure.
Westbound drivers should take the I-70 exit at Exit 205 in Silverthorne, head north on Colorado 9 toward Kremmling, then west on Hwy 40 through Steamboat Springs, then toward south on Colorado 13 at Craig to Interstate 70 at West Rifle. Eastbound drivers should detour in the opposite direction.
Visitors and local residents trying to access Glenwood Springs and the Roaring Fork Valley can get off the freeway at Exit 87, then return to Exits 90, 97, or 105.