Boulder, Colorado has registered seven October snowstorms with more than one foot of snow since 1950, every one happening during an El Niño winter.
Snowstorms are really complex weather events that are difficult to forecast, even just a few days in advance, so this isn’t to say that Boulder should expect a big snowstorm this month.
However, thanks to El Niño, the odds are tilted toward greater-than-average rain or snow in Colorado, and much of the southern half of the country, in late fall and early winter.