627
FXUS65 KGGW 211937
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
137 PM MDT Fri Aug 21 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.

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/thunderstorms that move northeast through the
area Saturday night and exit Sunday evening. Increased moisture
with PWATs near the 90th percentile may allow for storms to be
capable of producing heavy rain. Severe thunderstorms are not
expected but gusty winds could accompany them. Southeast winds
increase Saturday ahead of this disturbance that will make
conditions on Fort Peck Lake hazardous. A Lake Wind Advisory is in
effect from noon tomorrow to 3 AM Sunday.

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 decrease after the weekend and be generally light through the
next seven days.

FORECAST CONFIDENCE & DEVIATIONS:
Blended SREF in with PoPs to better match with neighbors. Confidence
for timing of precipitation chances over the weekend are moderate
with poor continuity from forecast runs.


&&

.AVIATION...
UPDATED: 1900Z

FLIGHT CONDITION: VFR

DISCUSSION: Quiet weather conditions are generally expected
through the TAF cycle. A disturbance moving in from the southwest
tomorrow, southeast winds will increase ahead of it with
scattered showers/thunderstorms overnight into Sunday evening.


&&

.FIRE WEATHER...
Seasonably hot temperatures with isolated thunder is expected
through Monday. Showers and thunderstorms begin Saturday night,
with overnight showers seeing wetting rains. Min RH values in the
20-40% range and good overnight recovery will mitigate fire
weather concerns through Monday, even with gusty winds. Warm and
dry conditions are expected to resume Tuesday.

&&

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

&&

$$

weather.gov/glasgow