High-Impact Weather and Climate Events

Two consecutive days of heavy convective precipitation in and near Fort Collins; on the 28th, over 10" fell in 6 hours in the Spring Creek watershed on the west side of Fort Collins. The resulting flash flood on Spring Creek heavily damaged Colorado State University and residential areas, and caused 5 fatalities. The following day, 13" fell on Pawnee Creek near Sterling, causing damaging flash flooding there.

Starting on April 13, a landslide caused by heavy precipitation dammed the Spanish Fork River, which then inundated the community of Thistle. The slide also destroyed the Rio Grande railroad tracks and US 6 and US 89. The landslide was the most costly geological event in Utah's history. Presidential Disaster declaration.

"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

"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 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

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

In 1988, Yellowstone National Park recorded almost no rain during the summer months. During the later half of summer, several smaller fires were started by lightning. High winds and dry conditions caused the fires to rapidly spread and merge. Before a cold front helped contain the fires, 9,000 firefighters, and 100 engines were mobilized to fight the blazes. Before containment, the complex burned 793,880 acres (36% of the park) and cost $120,000,000 in supression efforts. The fire destroyed 67 buildings along with backcountry and frontcountry infrastructure. The fires had far-reaching ecological impacts which have been the subject of numerous studies.

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.

Heavy rain and snowmelt caused severe flooding on Bear Creek, Turkey Creek, Plum Creek, and the South Platte River. The worst flooding in Denver since the June 1965 flood. Stapleton Airport measured 3.27" of precipitation in 24 hours.

The High Park fire was ignited by lightning after a very dry winter and spring, and burned over 87,000 acres and at least 259 homes.