Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 327 PM EST Thu Feb 20 2025 Valid 00Z Fri Feb 21 2025 - 00Z Mon Feb 24 2025 ...Colorado Rockies and Central High Plains... Day 1... Shortwave trough axis over Utah this afternoon will shift east over CO tonight and into western KS Friday morning. Weak jet streak aloft and PVA from the trough will produce widespread deep layer ascent to support snow over CO tonight with banding extending east over the Palmer Divide, through eastern CO and into western KS late tonight into Friday. Day 1 snow probs for >6" after 00Z are 40-80% in the I-70 corridor of north-central CO Terrain and around 30% on the I-25 corridor over the Palmer Divide near Castle Rock. Probabilities for >2" spread east along I-70 to Limon, but given the banding potential from upper forcing, there is potential for over an inch into KS. ...Pacific Northwest to the Northern Rockies... Days 2-3... Mid-level low pressure pushes across the Queen Charlotte Sound Friday evening with moisture advection and relatively short-lived moderate precip to the south over the Pacific Northwest Friday night. A broader trough approaches the Pacific Northwest this weekend with heavier precip then expected Saturday afternoon through Sunday. For Friday night expect snow levels to gradually rise to 5000 ft along the west side of the WA Cascades with cold air entrenched on the east side keeping snow levels around 2000ft. Day 2 snow probs for >6" are 50-80% for only the higher WA Cascades and far northern ID terrain. The broader moisture surge Saturday afternoon brings widespread 6000-8000 ft snow levels, keeping significant snow accumulations above Cascades pass levels, with 6000ft snow levels inland over the northern Rockies. Day 3 snow probs for >6" are 40-80% on the higher WA Cascades, western Sawtooths, ranges around Glacier NP, and the Tetons. Moderate precip will continue over terrain into Sunday night. Jackson ...Cold Key Messages are in effect for much of the southern U.S. as linked below... https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_2.png