4:10 p.m.: A severe thunderstorm warning is posted for Boulder, Niwot, Lyons and surrounding areas until 4:30 p.m., according to the National Weather Service. Winds up to 60 mph and quarter-sized hail is possible with the storm.

4:01 p.m.: At Denver International Airport, the threat of severe weather is causing delays. Departing flights are delayed an average of 44 minutes and inbound flights are being held at their origin airports until 4:30 p.m. mountain time, according to FlightAware.com. DIA has 514 total delays Friday with 21 cancellations.

3:55 p.m.: A severe thunderstorm warning is posted by the National Weather Service for Central City and Blackhawk until 4 p.m. Winds up to 50 mph and quarter-sized hail are possible.