Mark & Juanita wrote:

....
Having grown up on the plains of Colorado, and now living in Tucson
(where it does rain occasionally), as well as spending 17 years in Dallas,
the majority of rain changes I recall went from intermittent drops to
sprinkle to downpour, then back again. Tucson certainly seems to have more
of the abrupt demarcations than either Dallas or the Denver area. In
Colorado, I do know that the rain was often localized, i.e. while in town
we would experience heavy, but once we turned onto the dirt road home
(about 10 miles from town), we'd be kicking up dust. Even in those cases
though, the transition was more gradual than the rain/no rain demarcations
being discussed.
....

Just out of curiousity, which town on the eastern CO plains? We're
about 30 mi from CO line in SW KS...not sure whether you were meaning
you were 10 mi outside Denver or elsewhere.

Anyway, your description is pretty much true most of the time, but on
the high plains where dewpoints are typically low enough that general
rains are the rare exception in the warm months, it's the uplift that
generates the rainfall. When it then falls, the demarcation line is
quite often very abrupt and the "sprinkles" region may be only on the
order of feet rather than significant fractions of a mile.