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Winter Weather Forecast Discussion
(Caution: Version displayed is not the latest version. - Issued 2025Z May 09, 2023)
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Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
425 PM EDT Tue May 09 2023

Valid 00Z Wed May 10 2023 - 00Z Sat May 13 2023

...North Central & Colorado Rockies...
Days 2-3...

A reinforcing shortwave low currently approaching the central CA
coast will swing through the Lower Colorado River Basin late
tonight before reaching the central CO/NM border Wednesday night
where it slows to a northeastward drift through Friday. Strong
upper level divergence out in front of the negatively tilted
trough over northern NM Wednesday night low and beneath the left
exit region of a 100 knot 250mb jet streak will coincide with
increasing 700mb moisture flux from Pacific and western Gulf
sources up the High Plains through the north-central Rockies. The
500mb low will track with the Colorado Rockies on the northern
flank of the 500mb low track Wednesday night into Thursday
morning, which is ideal for heavy snowfall. While the upper low
and strong synoptic scale forcing aloft is present, there is a
noticeable lack of sufficiently cold air for a more widespread
snow event for early-mid May. Snow levels, from the Colorado
Rockies north through the Wind River, Absaroka, and Bighorn Ranges
of Wyoming to the Red Lodge area of Montana will be around
9,000ft. Latest Day 2 WPC snow probabilities for >6" are
moderately high for elevations >10,000ft over the CO Rockies and
moderate for the WY Ranges. Periods of snow will linger into
Friday morning as the upper low drifts northeast through the
central Plains, but not quite as heavy as Thursday morning. Snow
should taper off by Friday evening as the upper low heads for the
Upper Midwest by the start of the weekend.

The probability of ice accumulations greater than 0.25 inch is
less than 10 percent.