Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
229 AM EDT Tue Oct 21 2025

Valid 12Z Tue Oct 21 2025 - 12Z Fri Oct 24 2025

...CO Rockies...
Day 3...

An upper low in the Pacific (southwest of California) will move
into the Golden State on Wednesday, bringing some light snow to the
high Sierra (above 9500ft). On Thursday, it will cross through the
Four Corners region with antecedent LFQ jet ascent over
southwestern to central Colorado. Moisture levels will rise just a
bit to around +1 sigma (PW values 0.4-0.5 inches) though snow
levels will be high -- >10,000ft to start then decreasing overnight
Thursday into Friday morning to around 9500ft. At the end of this
forecast period, the upper low will likely be centered over south
central CO with snow continuing but starting to wind down. WPC
probabilities for at least 6 inches of snow are at least 40% above
11,000ft. This will likely impact high passes such as
I-70/Eisenhower Tunnel.



The probability of significant ice across the CONUS is less than
10 percent.

Fracasso