587
FXUS65 KGGW 281912
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
112 PM MDT Tue Jul 28 2026

.KEY MESSAGES...

- A smoke plume over the region will reduce visibility at times
  through Wednesday.

- Hot temperatures with highs in the 90s to near 100 are expected
  each day through Saturday or Sunday.

- Isolated showers and thunderstorms are possible at times today
  and tonight. Isolated to scattered storms are expected Wednesday
  afternoon and evening with a Slight Risk of severe storms in
  the east.

&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:

Upper ridging over the western U.S. will remain in place in
varying degrees through at least Saturday. Hot weather will
continue into the weekend with highs in the 90s most of the time
with some locations near 100 at times. With heat impact being
moderate in most areas today, will not issue any heat related
headlines for now.

Satellite showcases a large smoke plume stretched from eastern
Oregon across northern Montana. Smoke will continue to be over
the area today and tonight with unhealthy air quality and
variable visibility.

Weak waves will move through the ridge at various times through
Thursday to bring chances for showers and thunderstorms to parts
of the region. Models are showing increased instability and higher
dew points Wednesday afternoon and evening with a cool front
moving through that could lead to a few severe thunderstorms. Spc
has upgraded to a slight risk mainly east of the Yellowstone River
for Wednesday with a threat of large hail and damaging winds.

High on Thursday will be a few degrees lower before the ridge
strengthen Friday and Saturday. At this point, Saturday looks like
it will be very hot with highs above 100 in most areas.

Ridge moves east Saturday night and upper trough moves for Sunday
and Monday. A strong dry cold front on Sunday is expected to bring
gusty NW winds followed by much cooler temperatures on Monday.

FORECAST CONFIDENCE & DEVIATIONS:

High confidence in the hot weather continuing through Saturday.
Low confidence in timing any showers and thunderstorms.

NBM Deviations include HRRR/RAP blends to enhance visibility
reductions due to smoke and tweaking pops at times today and
tonight to account for weak waves moving through the area.


&&

.AVIATION...
FLIGHT CATEGORY: VFR - MVFR.

DISCUSSION: Upper ridging will continue to provide hot
temperatures to the region. Smoke and haze will impact visibility
through the TAF period with MVFR conditions possible at times.
There will be varying amounts of mid and high clouds across the
region tonight and Wednesday with isolated showers and
thunderstorms at times.

DENSITY ALTITUDE: Increased density altitude is expected the next
few days temperatures near or over 100 in the afternoon and
evening. Extra power and longer runway will be needed for
takeoffs.


&&

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

$$

weather.gov/glasgow