Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
356 PM EDT Thu Sep 30 2021

Valid 00Z Fri Oct 01 2021 - 00Z Mon Oct 04 2021

...Southern Rockies...
Day 1...

A closed low developing over the Four Corners region this
afternoon is forecast to move east overnight into Friday across
the southern Rockies, before ejecting northeast into the central
Plains Friday night.  Deep layer ascent along with ample moisture
will support widespread precipitation, with locally heavy totals
across southern Colorado and northern New Mexico Thursday night
and Friday.  With a backdoor cold front settling into southern New
Mexico, snow levels are on the decline, with accumulating snow
likely above 11,000 ft across the San Juan and Sangre de Cristo
mountains.  Locally heavy accumulations are possible, especially
along the higher peaks of the southern San de Cristo Mountains,
where upslope flow and a period of low level frontogenesis may
help bolster snowfall rates overnight.  For the higher peaks
northeast of Santa Fe, WPC probabilities for accumulations of
4-inches or more are now above 70 percent, with probabilities for
8-inches above 50 percent.  For the San Juan Mountains,
probabilities for accumulations of 4-inches or more remain above
50 percent. 

For Days 1-3, the probability of significant icing (0.25 inch or
more) is less than 10 percent.

Pereira