129
FXUS65 KGGW 082225
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
325 PM MST Mon Dec 8 2025

.DISCUSSION...

KEY MESSAGES:

- Very strong west winds 35 to 45 mph, gusting in excess of 60
  mph are expected to begin early tomorrow morning. High Wind
  Warning in effect through 5pm tomorrow.

- Mixed precipitation combined with cold ground temperatures is
  expected to lead to icy surfaces.

- Warm temperatures tomorrow then sharply falling minimum
  temperatures. Expect icy conditions.

- Prolonged period of snowfall through the end of the week.


WEATHER PATTERN OVERVIEW:

Strong cold air advection behind the next clipper system should
help mix down the stronger winds, especially for higher
elevations. NBM ensemble max wind gusts show widespread 50 to 60
mph gusts, with nonzero chances for gusts of at least 60mph.
While this is unlikely, conditions are favorable for high winds.
Post-frontal winds will shift to the NW and decrease fairly
quickly late Tuesday night.

The next round of precipitation spreading from west to east
tonight into Tuesday. Temperatures are mild enough to support
mainly rain and freezing rain. Road temperatures across NE
Montana are near or below freezing across the board. Given
evaporation from the strong winds, icing may begin to accumulate
even if precipitation occurs mostly as rain and/or if a little
snow melt adds to wet surfaces. Over time, the combination of the
cold ground and wintry mix is expected to lead to slippery
surfaces and difficult walking and driving conditions. Tuesday
evening, temperatures are expected to sharply fall into the teens
and 20s, which could exacerbate the icy conditions. Most of the
precipitation will be over with by the afternoon, but the impacts
will continue beyond into the overnight and the next system will
be approaching quickly.

Tuesday night through Thursday will feature low pressure bringing
an initial wintry mix which may include freezing rain, shifting to
snow. Ensemble guidance shows the potential for several inches of
snow to stack up, if not more in some places. Thus, this could be
a meaningful event for NE Montana, especially if snow accumulates
over pre-existing icy surfaces.

FORECAST CONFIDENCE & DEVIATIONS:

Blended HiRes models for day 1 winds. Blended 30% NBM90 through
Tuesday afternoon, 50% NBM90 for Tuesday`s wind gusts. Increased
winds in the Big Sheep Mts and south of Fort Peck Lake by hand
with DESI guidance.

Confidence increased for push of freezing rain then rain freezing
on impact tonight and tomorrow. Confidence is growing on a
significant meaningful winter storm toward the middle of the week
with a wintry mix changing to snow for at least portions of the
CWA.



&&

.AVIATION...

LAST UPDATED: 2130Z

FLIGHT CAT: IFR - VFR

DISCUSSION: Wintry mix of precipitation through tomorrow
afternoon. Look for icing concerns from mixed precipitation
tonight into Tuesday. Low stratus will push into TAF sites early
tomorrow morning with MVFR to IFR ceilings.

WIND: Strong west winds begin tomorrow morning. 20 to 30 kts
gusting to 50, with stronger gusts possible. Low level wind shear
at 2000 ft will be impacting the region through the early hours of
the morning.


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
High Wind Warning from 11 PM this evening to 5 PM MST Tuesday
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.

Winter Weather Advisory from 11 PM this evening to 2 PM MST
Tuesday 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