FOUS11 KWBC 260834
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
434 AM EDT Mon Oct 26 2026

Valid 12Z Mon Oct 26 2026 - 12Z Thu Oct 29 2026


...Northern Plains...
Days 1-2...

As the upper low over Colorado weakens to a trough overnight, a 
surface low will track across Kansas and eastern Nebraska Monday 
with enough comma head precip expansion to have some snow bands on 
the northwest side of the precip shield. This should intersect with
the Black Hills Monday along with dynamic enough banding for some 
snow accumulation in northwestern South Dakota and south-central 
North Dakota. Temperatures are marginal, and the trend was been a 
bit slower such that most snow would fall between 18-00Z when it is
less likely to stick. However, any snow that falls before sunrise 
or after sunset Monday would have a better chance of accumulating. 
Most likely forecast is for a broad swath of T-0.5" snow with some 
potential for an axis of 1-2" from the Black Hills northeastward. 
WPC probabilities of at least 4 inches of snow are about 10% in 
over parts of central SD and around 20-40% for at least 2" of snow.


...Cascades and Northern Rockies...
Days 1-3...

An active pattern for the Northwest U.S. is on tap for this week as
a series of low pressure systems and shortwave troughs comes down
the British Columbia coast and tracks over the Pacific Northwest
through at least the work week. Snow levels on the Cascades 
generally decrease over the next few days with values around 5000ft
through tonight, dropping to around 4000ft Tuesday night and
3000ft on Wednesday night. Light to moderate precip occurs off and
on. Day 1 snow probs for >6" are 50-80% for the higher Oregon 
Cascades with Days 2 and 3 shifted farther north to the Washington 
Cascades with probs for >6" 50-80% both days with snow down to 
Snoqualmie Pass level for Wednesday.

Mountain snow lingers over the northern Rockies with warm air
advection raising snow levels today over western Wyoming up 
through southwest Montana into the 8000ft range. Day 1 snow probs
for >6" are 30-60% for the Tetons up through the Beartooth range.
Snow levels then drop to around 5000ft early Tuesday where they'll
linger through the middle of the week with the precip focus
shifting north by Wednesday. Day 2 and 3 snow probs for >6" are
50-80% for northwest Montana and northern Idaho ranges.


For Days 1-3, the probability of significant ice across the CONUS 
is less than 10 percent.


Jackson


$$
--- MultiMail/DOS
 * Origin: capitolcityonline.net * KY, USA (618:250/10)