773
FXUS65 KGGW 201900
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
100 PM MDT Thu Aug 20 2026

.KEY MESSAGES...
- Typical mid to late August conditions are expected through the
  weekend with warm daytime conditions and comfortable nights.

- Dry weather is expected until late Saturday when the southwest
  monsoonal flow will bring another risk of thunderstorms.

- Warm and dry conditions resume next week as the western ridge
  rebounds.


&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:
NW upper flow over the area will give way to a building upper
ridge over the West into Saturday. This will give the area
generally dry conditions, but a nocturnal disturbance could drop
in across the northeastern zones tonight.

An upper level low off the Pacific NW coast will then move in our
direction and tag up with some SW monsoonal moisture for the
chance of showers/storms that move northeast through the area
Saturday night and exit Sunday evening. Severe thunderstorms are
not expected but gusty winds could accompany them. Southeast winds
increase Saturday ahead of this disturbance that could make
conditions on Fort Peck Lake hazardous.

Ridge rebounds early next week in the wake of the departing
disturbance to bring dry conditions with temperatures slightly
above normal.

Fire weather is expected to be quiet as humidity will be on the
rise with winds this weekend. Otherwise, winds are expected to
be generally light through the next seven days.

FORECAST CONFIDENCE & DEVIATIONS:
NBM followed for the forecast period. Confidence for timing of
precipitation chances over the weekend are moderate with poor
continuity from forecast runs. TFJ

&&

.AVIATION...
UPDATED: 1900Z

FLIGHT CONDITION: VFR

DISCUSSION: Quiet weather conditions are generally expected.

Scattered showers/storms in southern Canada could have some minor
effects late tonight as then drop into the KOLF and KSDY
aerodomes. Temporary gusty and erratic winds are the more likely
impacts.

Otherwise, with a disturbance moving in from the southwest
Saturday, southeast winds will increase ahead of it with scattered
showers/storms Saturday night into Sunday evening. TFJ

&&

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

$$

weather.gov/glasgow