DENVER - The biggest October snowstorm to hit Colorado in several years dumped up to 20 inches Thursday, grounding flights, closing highways, knocking out electricity - and jump-starting the ski season.
At one point, snow was falling at a rate of about 3 inches an hour in Denver. A 125-mile corridor from Colorado Springs to the New Mexico line was under a blizzard warning.
The storm began late Wednesday and turned highways wet and slushy in cities from Pueblo to Colorado Springs and Denver to Fort Collins.
Idaho Springs, about 25 miles west of Denver, reported nearly 20 1/2 inches. Some Denver suburbs received up to 10 inches. Denver International Airport, which got 5 inches, canceled more than 100 flights.
About 25,000 Denver-area customers lost electricity after trees and branches snapped under the weight of the wet snow and brought power lines down.
Large October snowstorms are common in Colorado, but this was the strongest in several years, National Weather Service spokesman Carl Burroughs said.
"We haven't had a real good storm like this in awhile," he said. "It dumped a lot of snow pretty quick and then moved on."
Interstate 70, the state's main east-west route, was closed for 150 miles from Denver to Burlington, near the Kansas state line.
On Colorado's wide-open Eastern Plains, residents and emergency managers braced for blowing snow and wind up to 45 mph. Red Cross officials sent supplies to Byers, about 30 miles east of Denver, in case the weather stranded travelers along I-70.
After Hurricane Katrina, "you think differently about everything," said Red Cross spokesman Robert Thompson. "I think we all learned good lessons from that."
At least one ski resort announced it would open Nov. 3, a week earlier than planned, in part because of the heavy snow.
"This storm really put them over the top," said Molly Cuffe, a spokeswoman for the industry group Colorado Ski Country USA. "Obviously when you get this much snow this early, it helps generate excitement."