072
FXUS65 KGGW 250920
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
220 AM MST Mon Nov 25 2024

.DISCUSSION...

KEY MESSAGES:

 - Lake effect snow is expected to continue southeast of Fort
   Peck Lake through mid afternoon today.

 - Below average temperatures will continue, with some areas
   seeing lows between 0 and 20 below zero for daily minimums.

 - Periodic disturbances throughout the week will aid in producing
   light snow showers across the area.


WEATHER PATTERN OVERVIEW:
A rather cold air mass and light northwest winds at low levels are
allowing light snow to occur to the southeast of Fort Peck Lake,
which is expected to eventually dissipate by mid afternoon today.
There is low confidence for when the lake effect snow will end.

The cold air mass in the wake of the exiting upper low pressure
system will maintain its strength throughout the week. Within the
northwest flow regime, shortwave troughs moving through the
overall flow will aid in enough upper level ascent to produce
minor snowfall accumulations across various parts of northeast MT.
Although sky cover will be a part of the equation for forecast low
temperatures, any clear nights late in the week and into the
weekend will allow lows to flirt with the 20 below mark along the
Canadian Border.

FORECAST CONFIDENCE & DEVIATIONS:

Blended NBM and NBM90 for winds to account for poor model boundary
layer performance. There is high confidence for below to well
below average temperatures occurring into the upcoming weekend.
There is low confidence on snowfall accumulation in response to
the shortwave troughs moving through the overall upper level flow
this week.

&&

.AVIATION...

LAST UPDATED: 0930Z

FLIGHT CAT RANGE: VFR-MVFR for KGGW, KOLF, and KSDY. MVFR-IFR for
KGDV.

DISCUSSION: Dry conditions are expected through 00Z Tuesday until
a weak upper level disturbance brings some scattered areas of
snowfall to KOLF and KGGW, which brings low to moderate confidence
of MVFR conditions occurring in snow showers. For KGDV, on and off MVFR
to IFR conditions are expected to persist through mid afternoon
in response to lake effect snow occurring to the southeast of Fort
Peck Lake.

WIND: Northwest 5 to 10 kts, becoming light and variable after
12Z, becoming east southeast 7 to 15 kts after 00Z Tuesday.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

weather.gov/glasgow