Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
246 AM EDT Wed May 7 2025

Valid 12Z Wed May 07 2025 - 12Z Sat May 10 2025


...Central and Southern Rockies...
Day 1...

Closed low over the Central Rockies will finally begin to fill and
lift off to the east today, while a secondary closed mid-level
impulse rotates cyclonically around it, moving over the Four
Corners tonight while dissipating. This evolution will result in
the primary forcing beginning to weaken over CO and NM due to
weaker lapse rates aloft, a lack of height falls, and decreasing
upslope flow. While this will force the most significant
precipitation to wind down quickly after 12Z this morning, the
secondary feature moving into the region will maintain at least
modest ascent and steepened lapse rates into tonight. This will
shift the focus of the heaviest snowfall from the Front Range and
Sangre de Cristos Tuesday night/Wednesday morning, to the San
Juans. Snow levels will remain elevated, around 8000-9000 ft,
keeping the heaviest snow confined to the highest terrain, and WPC
probabilities suggest a moderate risk (50%) for at least an
additional 6 inches of snow across the San Juans.


The probability of significant freezing rain across the CONUS is
less than 10%.


Weiss