107
FXUS65 KGGW 220915
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
315 AM MDT Sat Aug 22 2026

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

- Beginning this afternoon, the southwest monsoonal flow will
  bring another risk of thunderstorms to the region.

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

&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:
Upper ridge over the northern Rockies will begin to slide east
today in response to a trough pushing into the Pacific Northwest.

Showers and thunderstorms are expected to develop overnight as the
ridge axis moves east and a weak shortwave pushes through the
ridge. Monsoonal moisture to begin streaming into eastern
Montana and with high PWATs possible, some of the storms could
produce heavy rain. The Pacific NW trough will knock down the
ridge on Sunday with another round of storms. These storms could
pull down stronger winds aloft for a marginal severe risk.

Southeast winds will also be increasing today ahead of the
disturbance that will make conditions on Fort Peck Lake hazardous.
A Lake Wind Advisory is in effect from noon today to 3 AM Sunday.

Ridge rebounds early next week in the wake of the departing
trough 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
decrease after the weekend and be generally light through the
next seven days.

FORECAST CONFIDENCE & DEVIATIONS:
Added NBM90 to the winds for the Lake Wind period. Confidence for
timing of precipitation chances over the weekend are moderate
with poor continuity from forecast runs.

&&

.AVIATION...
UPDATED: 0900Z

FLIGHT CONDITION: VFR

DISCUSSION: Quiet weather conditions are generally expected
through the TAF cycle. As a disturbance moves in from the
southwest today, southeast winds will increase with scattered
showers/thunderstorms overnight into Sunday evening.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory from noon today to 3 AM MDT Sunday for
Central and Southeast Phillips-Central and Southern Valley-
Garfield-McCone-Petroleum.

&&

$$

weather.gov/glasgow