724
FXUS65 KGGW 291833
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
1233 PM MDT Mon Jun 29 2026

.KEY MESSAGES...
- Upper level low will bring showers and thunderstorms this
  afternoon and evening.

- Upper trough lingers most of this week with chances for showers
  and thunderstorms at times.

- Temperatures will gradually warm to near normal this weekend.




&&

.DISCUSSION...
WEATHER PATTERN OVERVIEW:
An upper trough is over the area. A weak, slow moving trough in
central Montana will bring a chance of showers and storms. Any
storms that form will be slow moving, and with quite a bit of
recent rain, hydrology will be important to watch in relation to
flooding. There is a strong southerly jet over the east, so any
thunderstorms that move through there have potential to drop wind
gusts to 50 mph with small hail. An isolated storm has the
potential to reach severe limits in this area with hail to one
inch and winds to 58 mph, but odds are low for this scenario.
There is heavy rain potential with any storm in this area, but
training of storms is less likely than in central Montana. This
activity is expected to be between 2 PM and 6 PM for the strongest
storms, with weaker convection expected to last through midnight
before ending. As the central Montana trough moves east tonight,
winds are expected to pick up by the morning, and lingering cloud
cover will allow for isolated showers and storms areawide in the
afternoon. Precipitation accumulations are expected to be light
tomorrow.

After a brief shortwave ridge moves through on Wednesday morning,
an active pattern appears to be on the horizon for Wednesday
through Friday. There is a 5 percent chance of an isolated severe
storm for Wednesday and Thursday, and a 10 percent chance on
Friday.

There is a decent shot of a ridge moving in after Friday according
to the latest GFS ensemble, so temperatures are expected to warm
up a bit closer to average this weekend.

FORECAST CONFIDENCE & DEVIATIONS:
The only deviation was PoPs for tomorrow and Wednesday night to
fill in the gaps with at least a low precipitation chance.

There is high confidence in precipitation and thunderstorm chances
today and tomorrow, as well as in the Lake Wind Advisories that
have been issued for Fort Peck Lake for today and tomorrow.

There is moderate confidence in showers and storms occurring
across the area for Wednesday and Thursday, and high confidence
for Friday. There is moderate confidence in an isolated severe
storm for Wednesday through Friday.

&&

.AVIATION...
UPDATED: 1830z Monday June 29th

FLIGHT CATEGORY: VFR most of the time. Areas of MVFR in
thunderstorms this afternoon and evening, as well as in the
morning tomorrow.

DISCUSSION: There is a trough over central Montana, as well as
over western North Dakota. The troughs will begin moving east this
evening, which well help aid in shower and storm activity from 20Z
to 05Z Tuesday. The trough in central Montana suggests low clouds
for a few locations in the morning. There is moderate to high
confidence of MVFR ceilings for KOLF and KGGW from 13Z to 21Z
Tuesday, and low confidence for KSDY and KGDV in that time frame.
An isolated shower or storm is possible after 18Z Tuesday, so
there is low confidence in MVFR conditions in thunderstorms then.
WINDS: Variable at 10 to 15 knots, becoming southwest at 8 to 14
knots after 04Z, becoming west at 15 to 25 knots with gusts to 35
knots after 15Z Tuesday.

&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 6 PM MDT this evening for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

Lake Wind Advisory from 6 AM to 8 PM MDT Tuesday for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

&&

$$

weather.gov/glasgow