High-Impact Weather and Climate Events

A very strong three-day upslope snowstorm brought huge snow amounts and blizzard conditions to most of the Front Range and the adjacent plains. Storm totals included 32" in Denver, and 87" in Rollinsville.

The Cameron Peak Fire is the largest wildfire in Colorado history as of 2020. It is also the third most destructive wildfire in Colorado history, in terms of homes destroyed, behind the Black Forest Fire in 2013 and the Marshall Fire in 2021.

"The Cameron Peak Fire was reported on Thursday, August 13 at approximately 1:48 PM. The fire was burning in steep, rugged terrain, approximately 25 miles east of Walden and 15 miles southwest of Red Feather Lakes near Cameron Pass.

The fire burned through an area of 208,913 acres on the Arapaho and Roosevelt National Forests in Larimer and Jackson Counties and Rocky Mountain National Park.

The cause of the wildfire remains under investigation. Large scale and long duration evacuations took place throughout the fire.

During the time the Cameron Peak Fire was burning, there was another fire (East Troublesome) burning simultaneously to the west of the Cameron Peak Fire, on the west side of the Continental Divide. On October 22, the East Troublesome Fire spotted over the Continental Divide, and created what became known as the “Thompson Zone” of the East Troublesome Fire.

On the Cameron Peak Fire, extreme temperatures, low humidity, rough terrain and gusty winds reaching over 70 miles per hour were just some of the elements that contributed to extreme fire behavior and rapid rates of spread. A major contributing factor to the large fire growth was the tremendous amount of beetle kill trees and the drought-stricken Ponderosa Pine, Engelmann Spruce and mixed conifer stands available as fuel.

After 62 days of burning, on October 14, the Cameron Peak Fire became the largest recorded wildfire in Colorado's history, surpassing the Pine Gulch Fire that burned near Grand Junction in 2020.

The Cameron Peak Fire was 100% contained as of December 2, 2020." - InciWeb

The most costly hailstorm in Wyoming history. Hail up to 2" in diameter covered most of Cheyenne, with accompanying rain totalling 1.46" of precipitation. Widespread damage to buildings and cars.

An F2 tornado tore a swath through the heart of Thornton, destroying 87 homes and damaging 600 others. The same thunderstorm complex also spawned tornadoes in Lakewood and Fort Lupton, damaging several dozen other homes, and caused damaging hail and non-tornadic winds.

A near-stationary thunderstorm produced record flash floods in Cheyenne and across the state. The storm killed 12 people, injured 70, and caused extensive damage to private and public property. Damage estimates ranged from $40 to $65 million. The NWS Forecast Office near the airport reported 6.06" of rain in 3 hours. In addition to the rain, there was hail up to 2" in diameter and 70 mph winds. Ten of the 12 deaths occured along Dry Creek when people attempted to cross flooded streets in their cars.

A massive, near-stationary thunderstorm dropped up to 12" of rain in 6 hours in Big Thompson Canyon, causing extreme flash flooding. Hundreds of homes were destroyed along Highway 34, and many motorists were trapped. The estimated discharge of 33,000 cfs at the canyon mouth was estimated to be a 300-year event. The most deadly natural disaster in Colorado history.

"A rare nocturnal severe thunderstorm developed over southern El Paso County during the early morning hours of June 13th, 2018. The severe thunderstorm dropped 3.0" hail over the southern Colorado Springs metropolitan area and Fountain. The estimated damage caused by this event was around $169 million dollars. Follow this link for an in-depth meteorological analysis and for more images: https://www.weather.gov/pub/20180613_ElPaso_Hail" - National Weather Service

Drought forced 36% of municipal water suppliers to raise water rates in an effort to increase conservation. In 1977, crop losses in hardest-hit areas ranged from 40-100%. The 1976-77 winter snowpack was limited, causing economic hardship for the ski industry. The statewide summer Palmer Drought Index was -5.3, the 3rd lowest on record.

"A very strong severe thunderstorm develop over Teller County during the afternoon of August 6th, 2018, then traveled southeast over the Highway 24 corridor, reaching the Cheyenne Mountain Zoo. The severe thunderstorm dropped 3 - 4" hailstones over the Cheyenne Mountain Zoo and southern Colorado Springs. The estimated damage caused by this event was $173 million. A good overview of the injuries at Cheyenne Mountain Zoo can be found here. Follow this link for a meteorological write-up of the event: https://www.weather.gov/pub/20180806_ElPasoHail" - National Weather Service

"A powerful tornado swept north-northwestward across Weld County and into Larimer County, carving a path of destruction, nearly 39 miles in length. The tornado, up to one-mile wide at times, initially touched down northeast of Platteville and finally lifted 6 miles west-northwest of Wellington. A tornado assessment in the aftermath of the tornado revealed extensive areas of damage. On the enhanced Fujita Scale there were pockets of EF3 damage, mainly near the Missile Silo Park Campground, and to businesses and homes in eastern Windsor. 
There was one fatality, and 78 injuries. One man was killed when he tried to escape the trailer park in his motor home. Preliminary estimates from FEMA indicated 850 homes were damaged, and nearly 300 homes were significantly damaged or destroyed. Privately insured damages totaled $147 million, and the Poudre Valley Rural Electric Associated reported $1 million of damage to electric transmission lines." - NWS