The presence of a warm and moist southwesterly flow aloft overrunning an Arctic airmass with shallow post frontal upslope produce a band of very heavy snowfall across the Denver metro area for several hours.  The enhanced band of heavy snow extended west into the Front Range mountains and foothills.  Snowfall rates up to 2 inches per hour were observed.  Storm totals in and around metro Denver ranged from 6 to 12 inches with up to 18 inches in the mountains.  Multiple accidents occurred during the evening hours of the 16th as the snow quickly piled up.  A total of 300 flights have been canceled at Denver International Airport as a winter storm moved through the metro area early morning hours of the 17th.
In the mountains and foothills, storm totals included: 18 inches at Arapahoe Basin ski area, 16 inches at Copper Mountain and Loveland Ski Areas; 14 inches at Grizzly Peak SNOTEL, 12 inches near Conifer and at Fremont Pass SNOTEL, 11 inches at Winter Park Ski Area, 10.5 inches at Bergen Park, 10 inches near Dillon, Echo Lake, Jones Pass and Summit Ranch; with 9.5 inches at Aspen Springs and Evergreen.  In and around metro Denver,  storm totals included: 11.5 inches in Wheat Ridge, 11 inches in Arvada, 9 inches near Morrison, 8 inches at Denver International Airport,  Denver/Stapleton, Marston Reservoir and Ralston Reservoir; 7.5 inches in Westminster; 6.5 inches, 5 miles northeast of Westminster; with 6 inches in Aurora, 5 miles west-northwest of Brighton, Englewood and near Louisville.

Winter Storm in S & SE GRAND / W CENTRAL & SW BOULDER / GILPIN / CLEAR CREEK / SUMMIT / N & W PARK COUNTIES ABOVE 9000 FEET, COLORADO
From 15-DEC-16 17:00:00 to 17-DEC-16 05:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Storm totals included:  18 inches at Arapahoe Basin ski area, 16 inches at Copper Mountain and Loveland ski areas; 14 inches at Grizzly Peak SNOTEL, 12 inches at Fremont Pass SNOTEL, 11 inches at Winter Park ski area, with 10 inches near Dillon, Echo Lake, Jones Pass and Summit Ranch.

Winter Storm in JEFFERSON & W DOUGLAS COUNTIES ABOVE 6000 FEET / GILPIN / CLEAR CREEK / NE PARK COUNTIES BELOW 9000 FEET, COLORADO
From 16-DEC-16 15:00:00 to 17-DEC-16 15:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Storm totals included:  12 inches near Conifer, 10.5 inches at Bergen 9.5 inches at Aspen Springs and Evergreen; 9 inches 4 miles west-southwest of Conifer, Georgetown and Roxborough State Park; 8.5 inches near Bailey, with 8 inches near Pine Grove.

Winter Storm in BOULDER & JEFFERSON COUNTIES BELOW 6000 FEET / W BROOMFIELD COUNTY, COLORADO
From 16-DEC-16 15:00:00 to 17-DEC-16 15:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Storm totals included:  11.5 inches in Wheat Ridge, 11 inches in Arvada, 9 inches near Morrison, 8 inches at Marston and Ralston Reservoirs; 7.5 inches in Westminster, with 6 inches near Louisville.

Winter Storm in N DOUGLAS COUNTY BELOW 6000 FEET / DENVER / W ADAMS & ARAPAHOE COUNTIES / E BROOMFIELD COUNTY, COLORADO
From 16-DEC-16 18:00:00 to 17-DEC-16 03:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Storm totals included:  8 inches at Denver International Airport and Denver/Stapleton; 6.5 inches, 5 miles northeast of Westminster; 6 inches at Aurora, 5 miles west-northwest of Brighton and near Englewood; with 5 inches at the Denver Museum of Natural History.