Fall's first big weather shift: Cold front brings rain, wind and mountain snow to Colorado

Fall officially begins Monday, bringing cooler temperatures and Colorado's first real taste of seasonal weather changes.

Temperatures will begin to slide on Monday as a cold front sweeps through the state from north to south during the early afternoon. Winds will shift out of the north, with gusts up to 30 mph expected behind the front.

Despite the chillier air, highs will still manage to reach the 70s on Monday — but it won't feel that warm for long. By late afternoon, showers and isolated thunderstorms are likely to develop, particularly along the I-25 corridor and onto the eastern plains.

A few of those storms could produce strong wind gusts, but overall, the threat for severe weather is low.

As colder air moves into the high country, snow levels will drop to around 9,000 feet by early Tuesday morning.  Accumulating snow is expected on the higher peaks of the northern Front Range, including areas around Trail Ridge Road and Berthoud Pass. 

No widespread travel alerts are in place, but slick conditions are possible on mountain passes late Monday night into Tuesday morning. 

Tuesday will be the coolest and wettest day of the week, and the impacts will be felt from the mountains to the metro. Because of the potential for cooler temperatures, steady rainfall, and early-season snow in the high country, a First Alert Weather Day has been issued for Tuesday.

• Highs on the plains: 50s to low 60s

• Rainfall: Light to moderate through most of the day

• Snow: Accumulating above 9,000 feet

This early taste of fall won't last long. By Wednesday, the storm system moves out, and high pressure builds back in. That means dry conditions and a gradual warm-up, with temperatures returning to the 70s and even low 80s by the end of the week.