High-Impact Weather and Climate Events

By some measures, this is still the most costly and destructive flood event in Colorado history. Intense thunderstorms near Castle Rock dropped over 14" of rain in several hours, causing extreme flooding on Plum Creek, Cherry Creek and the South Platte River. The flood zone included two-thirds of Denver's industrial area. The Purgatoire River and lower Arkansas River also experienced severe flooding; 11" of rain fell at Holly and over 15" near Lamar in one day.

A record-breaking blizzard developed across portions of Colorado Wyoming and Nebraska on March 13th and 14th, 2019. The record-setting area of low pressure reached a minimum central pressure of 971 mb across eastern Colorado. This set an all-time pressure record for the state.

La Junta recorded its strongest wind gust during the bomb cyclone — an 88 mph gust. An 80 mph gust recorded at Denver International Airport during the heart of the storm made it the strongest non-thunderstorm wind gust recorded there. Winds reached a record 96 mph in Colorado Springs.

The "Bomb" Cyclone rapidly intensified from the evening of the 12th through the morning of the 13th. This rapid intensification brought extremely strong winds and very strong dynamic lift which generated extremely heavy snowfall over Wyoming and Nebraska (www.weather.gov). Subsequently, the blizzard resulted in widespread flooding across the US (www.cnn.com), affecting many states.

Severe thunderstorms in late afternoon produced giant hail up to baseball size (2.75") that pummeled a swath extending from Golden northeast through north Denver. Hail size exceeded 2" across Denver and Jefferson Counties and damaged over 50,000 homes, over 100,000 vehicles, and many businesses. Colorado Mills Mall in Lakewood was closed for 6 months to repair roof and interior damage. NOAA officially estimated damages of $2.5B, or $3.9B in 2022 dollars, which is higher than an early estimate of $1.4B by RMIIA that was widely reported. In either case, it was the most costly hailstorm in Colorado history.

A near-stationary weather system funneled copious subtropical moisture into the Front Range, leading to one-week rainfall totals of 10-18" over a large area. Creeks and rivers from the Wyoming border to Colorado Springs flooded, with the worst flooding on the Big Thompson River, Little Thompson River, St. Vrain Creek, Lefthand Creek, and Coal Creek. Over 20,000 homes were damaged or destroyed. Incredible and widespread damage to civil infrastructure (roads, bridges, water conveyance and treatment) on the Front Range.

"On the evening of June 18th, a severe storm in northern Colorado produced baseball-sized hail and powerful winds. The storm damaged cars and homes in the Boulder area, before moving northeast toward Fort Morgan, where 70 mph winds and baseball-sized hail wreaked havoc in Morgan County. Storm reports included heavy rain in many parts of Colorado, with funnel clouds and tornadoes in the Eastern Plains." - NOAA NCEI

The worst year of a multi-year drought (2000-2002 for eastern Colorado, and 2000-2004 for western Colorado). One of the driest water years on record in all parts of the state, with very low snowpacks, extremely low runoff, many large wildfires, and severe agricultural impacts. The statewide summer Palmer Drought Index was -8.7, the lowest on record.

A supercell thunderstorm traveled from Estes Park to Colorado Springs, passing directly over Denver with large hail. Thousands of roofs and cars were damaged. At the time, the costliest hailstorm in US history.

$1,096,046,204 | Over 9" of rain fell in the Pueblo area, causing extreme flash flooding on the Arkansas River. A bridge collapse in Pueblo caused many fatalities. Related rain events caused flooding and damage on the South Platte River, Coal Creek, Boulder Creek, and St. Vrain Creek.

Part of NCDC's billion-dollar disaster list. In total, the estimated damage the severe storms and hail caused in CO is over $1B.

"Unusual overnight severe weather hit the metro area Wednesday into Thursday, bringing lightning, thunder, heavy rain, hail and flooding to much of the region. Despite several Tornado Warnings, there were no confirmed tornado touchdowns with the round of late night storms. Hail hit the southern and western parts of metro Denver especially hard. Several inches were on the ground Thursday in places such as Castle Rock, Parker and Highlands Ranch." - FOX31

A line of severe thunderstorms with damaging winds dropped large hail over a swath of the Denver metro area and spawned two weak tornadoes.