FOUS11 KWBC 280732
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
332 AM EDT Tue Apr 28 2026

Valid 12Z Tue Apr 28 2026 - 12Z Fri May 01 2026

...Central & Southern Rockies... Days 1-3...

Periods of light-to-moderate snow will linger for a little longer
this morning with an additional 3-6" of snowfall possible in the
Park Range and Flat Tops of the CO Rockies. Snow should taper off
after midday as the shortwave trough responsible for the mountain
snow moves into the Central Plains.

Following a break in the action between Tuesday afternoon and
Wednesday evening, a closed 500mb low (closed at 300mb as well)
west of Baja will head east at the same time that a secondary
impulse over the Great Basin results in 500mb height falls over the
CO Rockies. This "squeeze-play" between the pair of upper-level
troughs and a 500mb ridge over Mexico fosters a robust subtropical
stream, culminating in 200mb winds over the Central Plains that
exceed the 99.5 climatological percentile per ECMWF SATs. In
addition to this textbook jet-streak dynamics setup, high pressure
over the Northern Plains will bleed south down the Front Range and
Sangre De Cristo, forcing favorable easterly upsloping low-level
winds to ensue. This is a classic setup for mountain snow (and
valley/Plains rainfall) in a region that could sorely use any
precipitation of note.

The latest forecast shows snow increasing in intensity along the CO
Front Range throughout the day on Thursday, then along the Sangre
De Cristo Thursday afternoon into Thursday night. There remain some
differences in model guidance regarding the timing and strength of
the approaching 500mb low as it tracks over northern Mexico Friday
morning. Regardless, low-level easterly flow should linger long
enough into Friday to keep mountain snow going through at least the
first half of the day. Most guidance agrees snow tapers off by
Friday evening as the 500mb low races east into the Southern
Plains. WPC probabilities show at least moderate chances (>50%) for
snowfall totals >8" above 9,000ft in the CO Front Range and Sangre
De Cristo, with the Park Range having similar probabilities above
10,000ft. Some of the tallest CO peaks (including Pikes Peak) could
witness localized snowfall amounts surpass 20". Some light snow is
possible over the Palmer Divide and Raton Pass (1-3", but most
snow is a welcomed sight for drought-stricken CO and NM.

The probability for significant icing over one-tenth of an inch is
less than 10 percent.

Mullinax

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