High-Impact Weather and Climate Events

100 mph winds caused extensive damage to homes.

The South Canyon Fire had been burning for four days when a cold front with strong and erratic winds passed over the fire, causing a blowup that killed 14 wildland firefighters within an hour of the front's arrival. The front was well-forecast but the information was not communicated to the front lines.

The driest calendar year on record for Wyoming, with 69% of normal precipitation. Spring and summer were especially dry, at 55% of normal. Livestock producers were heavily impacted.

A series of convective events including heavy precipitation, hail, and a tornado caused widespread damage. 6" to 8" of rain fell in the North Platte Valley, overflowing the Interstate Canal and inundating Ft. Laramie with 5' of water. Torrington experienced 2" of rain along with baseball-sized hail, which severely damaged crops in the valley. A tornado southwest of Torrington uprooted trees and destroyed two farmhouses.

Thunderstorms and cloudburst dumped locally torrential rains over the Absaroka Range, swelling the North and South Forks of the Shoshone River. The flood damaged lodges and ranches in the area. Hail, heavy rains, and wind caused scattered crop losses along the east slopes of the Absarokas. A hailstorm and windstorm struck the Cowley-Lovell area, causing heavy crop losses. Farmers in the Heart Mountain area reported a 20 percent loss to some of their crops.

Slide blocked Highway 89, forcing Afton residents to detour 75 miles through Idaho to get to Jackson.

Estimated to be a 500-year event with an estimated peak discharge of 300,000 cfs at Black Canyon of the Colorado River. Newspaper stories indicate that the event was caused by an unusually high snowpack and the late arrival of spring.

The worst year of a 4-year drought (1987-1990) that affected most of the Northern Great Plains. The 3rd-driest calendar year on record for Wyoming, with 72% of normal precipitation. Extremely dry summer led to huge wildfires in the Yellowstone region.

Huge upslope snow event impacted much of Front Range; 46" storm total for Denver is still the all-time record-largest snowstorm, 86" in Georgetown. Denver was brought to a standstill.

"There were 45.7 inches of snow on the ground in Denver on December 5, 1913. For four days, a massive blizzard hit Colorado. It remains the largest snowstorm recorded in Denver's history. According to the Denver Public Library, the snow began on Dec. 1 and continued through Dec. 5, leaving the city blanketed under more than 3.5 feet of snow. History Colorado Center said schools and businesses were closed for days and some residents even slept at work because they were unable to get home." - 9News

1977 was the driest water year on record for the Western Slope at the time, at 62% of average precipitation. 1977 also had the lowest water-year streamflows on the upper Colorado River. Both records were broken in 2002. Oct-Dec 1976 still holds as the driest Oct-Dec period in Colorado recorded history (1895-2021). The lack of snow seriously impacted the ski industry and spurred widespread adoption of snowmaking.