According to weather.com meteorologist Chris Dolce, a slow area of low pressure combined with a moist, southerly flow makes for a devastating cocktail that will "keep the threat of heavy rain and flooding in place into the weekend."
Flooding extends all along the Front Range mountains, including the cities of Colorado Springs, Denver, Fort Collins, Greeley, Aurora and Boulder.
The University of Colorado has also closed all classes, and against the advice of the school spokesman, students have ventured outside to Instagram footage of the flood waters.
You can take a look at some of those Instagram videos below.
The Associated Press contributed to this report.