About half of Colorado under a Flood Watch with soaking rain on the way
Tuesday is the final day to soak warm temperatures before a cold front brings much cooler and wetter weather.
The front was in central Wyoming Tuesday morning and based on the speed of the front, it should arrive in the Denver metro area no later than midnight Tuesday night.
Before the front arrives, temperatures will reach near 90 degrees again around Denver, Boulder, and Fort Collins on Tuesday. It should be the 67th day this year reaching at least 90 degrees in Denver (the third most on record) and the 10th day in September which is unprecedented in Denver's history.
After the front arrives Tuesday night, temperatures will be at least 30 degrees cooler in most areas on Wednesday. The Denver metro area will likely stay below 60 degrees all day.
The chance for rain along the Front Range will start Tuesday night but the best chance should wait until later in the day on Wednesday. Eventually the chance for rain will reach near 100% by Wednesday night.
Rain will arrive much earlier in the high country and especially over the southwestern mountains of Colorado where over 2 inches of rain may fall in some areas.
The National Weather Service has already issued a Flood Watch for much of the Western Slope and the mountains including Park, Summit, and southeast Ground Counties. Excessive runoff in these areas may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone areas. Rock and mudslides will be possible on highways that traverse the mountainous terrain.
The Denver metro area should get less than 1 inch of rain in most areas so the flooding threat is considerably smaller compared to western Colorado. A few lingering showers are expected on Thursday before much drier and warmer weather returns for Friday and the weekend.
