Subj : HVYSNOW: Probabilistic He
To   : All
From : Mike Powell
Date : Mon Oct 20 2025 08:39:35

FOUS11 KWBC 200551
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
151 AM EDT Mon Oct 20 2025

Valid 12Z Mon Oct 20 2025 - 12Z Thu Oct 23 2025

....Northern Rockies...
Day 1...

At the start of the period this morning, the upper trough axis
will be exiting the Rockies with heights building in quickly this
afternoon to Montana/Wyoming. Lingering mainly upslope-driven snow
this morning will end by the afternoon over parts of western
Montana into the Big/Little Belts, Absarokas, and Bighorns. WPC
probabilities for at least an additional 4 inches of snow are
20-60% here and some high mountains peaks could see another 6
inches of snow.

Elsewhere, light snow is expected over the CO Rockies this morning
near the cold front before ending this afternoon. No appreciable
snow is expected until Wednesday over the Sierra as an upper low
moves ashore but snow levels there will be very high (>9000ft).


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

Fracasso



$$
--- SBBSecho 3.28-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)

.