068
FXUS65 KGGW 042147
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
247 PM MST Sun Jan 4 2026

.DISCUSSION...

KEY MESSAGES:
- Freezing fog is expected to linger tonight along the river
  valleys. Dense fog is expected in Sheridan and Roosevelt county
  and along low lying river valleys.

- Warmer temperatures and drier weather through the end of the
  week.

WEATHER PATTERN  OVERVIEW:
Widespread dense freezing fog has diminished this afternoon as a
warm front moved through the area partially shallowing out the
inversion across the region. Chances for dense fog return tonight.
Differently from the past few days, dense fog would not be from
low stratus clouds but rather radiation fog with the warmer
temperatures this afternoon and light winds.

Broad upper ridging extending from the northern Rockies into the
Dakotas will slowly shift eastward and weaken. Daytime
temperatures will be seasonably warm to slightly above normal with
lows in the teens. Zonal flow ahead of a deepening trough over the
PNW will allow for brief and weak shortwave influences bringing
chances for precipitation for southern zones. Wintry mix,
including freezing rain, may be possible Monday night into the
early hours of Tuesday morning.

After midweek a trough will move through the area pulling and
arctic cold front and cooling conditions down briefly. Saturday
onward, while synoptic ensemble features break apart hear in
general and ridge to the west looks to move in warming things up
whether mildly at the base of the ridge or wildly if the tip forms
a chinook before pushing through instead. This could lead to good
melt days, but with a lot of high cloud cover.

FORECAST CONFIDENCE & DEVIATIONS:
Day 1 visibility used 100% CONSShort. Blended day 1 winds with
HRRR and wind gusts with NBM90.

Low confidence in dense fog. Moderate confidence in wintry mix
with freezing rain in southern zones Monday night. Models still
have little agreement on precipitation location in northeast MT.

High confidence in warmer than average high temperatures through
the week.

&&

.AVIATION...
LAST UPDATED: 2100Z

FLIGHT CAT RANGE: Airport Shutdown - VFR

DISCUSSION: VFR conditions this afternoon with chances for IFR to
airport shutdown for patchy fog for the terminals tonight. There`s
low confidence in timing and location of dense fog, if it
materializes or not this evening. Differently from the past few
days, low visibilities would not be from low stratus and would
likely stay in river valleys.

LLWS: Low level wind shear will be present close but not directly
over terminals through tomorrow morning.

WIND: Light and variable becoming generally west by early morning
tomorrow.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from 6 PM this evening to 11 AM MST Monday
for Eastern Roosevelt-Sheridan-Western Roosevelt.

&&

$$

weather.gov/glasgow