300
FXUS65 KGGW 082153
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
253 PM MST Wed Jan 8 2025

.DISCUSSION...

KEY MESSAGES:

 1) Rain and wintry mix may end as light snow as it slides east
this evening.

 2) Though temperatures are above freezing in many places, some
ground surfaces are subfreezing, leading to icy surfaces. This
problem may increase tonight as temperatures fall.

 3) An Alberta clipper is expected to cross the region Friday and
Saturday bringing accumulating snow.

WEATHER PATTERN OVERVIEW:

A Winter Weather Advisory is now in effect for all of NE Montana
through 5 AM Thursday. Lingering rain and mixed precipitation may
end as light snow before ending tonight across NE Montana. Given
precipitation type uncertainties and gusty northwest winds with
cold air advection - will leave mention of patchy blowing snow.
Admittedly, these odds are diminishing over time. That, said,
while temperatures are near and above freezing area wide, ground
temperatures are below freezing. This is leading to surfaces
starting to become icy. Conditions are expected to become more
treacherous tonight as temperatures fall down into the mid teens
to mid 20s. Given the impacts, have decided to issue headlines
with the forecast cycle as it will help to underscore messaging of
hazards into tonight. Even as weather improves, the icy and slick
travel conditions will be worst overnight.

Upper ridging will lead to dry conditions on Thursday before the
next system arrives. A Pacific shortwave will traverse the
Canadian Rockies and spin up a lee low over Alberta. This
feature will track southward into the northern Plains on Friday,
with snow Friday into Saturday. Snow may stick around through the
weekend with arctic high pressure pushing into the plains.

FORECAST CONFIDENCE & DEVIATIONS:

High confidence on icy conditions exists through tonight as
temperatures drop into the teens and 20s in the presence of wet
roads. Medium confidence exists for the Friday and Saturday
period, mainly due to precipitation placement and amount still
being a couple days out. No significant changes were made for now
to NBM baseline but did use headlines to better underscore the
impacts expected overnight even as precipitation ends. This will
help highlight that the worse conditions may come even hours
after the rainfall is over.



&&

.AVIATION...
MVFR will likely dominate the landscape through this evening with
rain and wintry mix finishing its track across the area. Skies
will clear tonight. Northwest winds of 15 to 25 kts, gusting to 30
kts will continue this evening, gradually diminishing to 10 to 20
kts on Thursday.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 5 AM MST Thursday for Central and
Southeast Phillips-Central and Southern Valley-Daniels-Dawson-
Eastern Roosevelt-Garfield-McCone-Northern Phillips-Northern
Valley-Petroleum-Prairie-Richland-Sheridan-Southwest Phillips-
Western Roosevelt-Wibaux.

&&

$$

weather.gov/glasgow