1:30 PM MDT, Wednesday, September 18, 2019
I haven’t written much because we have been in a rather uneventful pattern for a while. With a few local exceptions, the Front Range region has generally been warmer and drier than average since mid July. Average afternoon temperatures in the lower elevations have now fallen to the mid 70s, and we are likely to be around that (or a little warmer) through the Monday (and the autumnal equinox is Monday at 1:30 AM MDT). There is a small chance for afternoon showers or thunderstorms (and maybe a light coating of wet snow in the highest elevations), mainly Thursday or Friday, but many areas are likely to come through with no significant precipitation. The weekend is looking dry.
The next chance for significant widespread precipitation is late Monday or Tuesday, but even that is iffy. The path and development of that particular storm is too uncertain at this time for me to be confident of some good precipitation, but it’s worth watching.
The average time for the first measurable snow in places like Denver, Boulder, and Fort Collins is mid October. In the last 70 years the odds are about 1-in-4 for the first snow to occur in September. In the last 18 years measurable snow only occurred once in September (in 2014) along the urban corridor. So you can say we are due, but there are no obvious signs yet that this will be a year for September snow.