376
FXUS65 KGGW 162222
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
322 PM MST Tue Dec 16 2025

.DISCUSSION...

KEY MESSAGES:

- The High Wind Watch has been upgraded to a High Wind Warning for
  all of northeast Montana.

- The active and windy day will suddenly include colder and
  snowier conditions by Wednesday evening.


WEATHER PATTERN OVERVIEW:

A strong low pressure system developing off the Canadian Rockies
will strengthen even more as it approaches our region tomorrow
(Wednesday morning). Model agreement is lining up very well to
support a widespread, long-duration wind event across our entire
northern Rockies and northern High-Plains regions. The High Wind
Watch from earlier has now been upgrade to a High Wind Warning.

Morning winds will generally be from the south, but a turn more
from the west will signal the arrival of the stronger winds.
Timing will begin around 9 AM for Zortman, around 11 AM for Malta
and Winnett, around 1 or 2 PM for Glasgow, Opheim, and Jordan,
around 3 PM for Scobey, Wolf Point, and Circle, around 4 PM for
Plentywood, Culbertson, Sidney, and Glendive.

Recent warming and melting has provided plenty of evaporation, and
the approaching low pressure system will create just enough
convection instability to support scattered rain showers and an
isolated thunderstorm during the mid-day hours. Indeed, the
convective outlook from SPC has most of our region outlined for
general thunderstorms. Later by Wednesday evening, a strong cold
front will push south from Saskatchewan and bring a round of
snowfall to many locations. While snowfall amounts are not
expected to be much more than an inch or two, the persistent
strong winds could easily lead to periods of near-white out
conditions or snow squalls. The question mark is whether or not
it ends up being a short duration snow squall or will the snow
last 3+ hours to meet the criteria for a blizzard warning. Any
snow cover that remains from the current warm weather will be
crusted and not blow. So, any blowing snow that occurs will have
to come from new snow.Travel during all this time will be
dangerous, especially for high- profile vehicles.

The strong winds will quickly diminish overnight Wednesday night,
becoming near calm Thursday morning.

The next following snow storm will be on Friday and confined more
toward the northeast corner of the state and northern North
Dakota.
FORECAST CONFIDENCE & DEVIATIONS:

Blended best model agreement I could find for precip, snow, and
winds for Days 1 and 2.

Confidence is high for the strong winds Wednesday afternoon and
night. Confidence is moderate for snow and blowing snow Wednesday
night but low on whether or not it will last long enough to meet
blizzard conditions.


&&

.AVIATION...

UPDATED: 2200Z / 3 PM / Tuesday, Dec 16

FLIGHT CATEGORY: VFR becoming MVFR just after the end of this TAF
cycle. Then isolated periods of VLIFR in possible snow squalls
Wednesday evening.

DISCUSSION: A strong low pressure system is approaching the region
from the Canadian Rockies. Confidence continues to increase for a
widespread High Wind event for most of the day (Wednesday late
morning through midnight).

WINDS: Tonight, near calm, then overnight increasing from the
south around 5 to 10 kts. Wednesday morning from the south and
southwest around 15 to 20 kts. Wednesday mid-day from the
southwest at 20 to 25 kts. Wednesday afternoon from the west at
30-40 kts and gusts to around 50-55 kts. Wednesday evening/night
from the west at 50 kts and gusts in excess of 60 kts. Thursday
12Z, winds finally diminish back down to less than 20 kts.

LLWS: There will be periods of LLWS throughout the TAF cycle.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
High Wind Warning from 8 AM Wednesday to 3 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