643
FXUS65 KGGW 250600
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
1200 AM MDT Sat Jul 25 2026

.KEY MESSAGES...

- Dangerously hot high temperatures near 100 degrees are expected
  for today and Sunday. Look for little overnight recovery with
  lows tonight in the mid 60s to the mid 70s.

- Isolated to scattered dry thunderstorms are possible during this
  afternoon and evening. A few may be severe with particularly
  strong wind gusts in excess of 60 mph.

- The hot and dry weather conditions will raise fire weather
  concerns at times over the next few days. A Red Flag Warning
  remains in effect for portions of the area for Saturday due to
  lightning.

&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:

Upper ridging over the western U.S. will remain the dominant force
this weekend with triple digit heat during the afternoon hours
today and Sunday. Low temperatures tonight will struggle to get
down to the mid 60s to mid 70s, making for uncomfortable sleeping
conditions for those without air conditioning. Will continue the
Extreme Heat Warning through 10pm Sunday evening.

There will be enough instability with a shortwave trough
approaching from the southwest this afternoon and evening to
initiate a few dry thunderstorms. HREF max ensemble wind gust
guidance continues to support the potential for damaging wind
gusts as a primary threat, further noting the inverted-v forecast
soundings across the area. A Red Flag Warning for fire zones 134,
135, 136, and 137 continues for this afternoon due to the
lightning risk on dry fuels. As an aside, haze and some smoke will
continue at times to be a problem from upstream wildfires.

Ensembles continue to show the hot temperatures continuing through
at least the early and middle part of next week, with highs in the
90s to around 100 degrees each day.

FORECAST CONFIDENCE & DEVIATIONS:

Pops were adjusted for consistency and collaboration with
neighbors in support of near term high resolution guidance. There
is above average confidence for hot temperatures through the
balance of the weekend and into the first part of next week, with
only some uncertainty due to impact from smoke and haze.
Confidence is above average for isolated convective coverage at
least this evening, though lower for specific timing and
placement.


&&

.AVIATION...

UPDATE TIME: Saturday July 25 at 0545Z.

FLIGHT CATEGORY: VFR prevailing, temporary MVFR possible with
visibility reductions in thunderstorms and in haze.

SYNOPSIS: Upper ridging will continue to provide hot temperatures
to the region. Haze will continue to be possible at times due to
smoke from upstream wildfires. Isolated to widely scattered
thunderstorms are possible during afternoon and evening hours,
which could track near area terminals. The primary timing would be
from 22-04Z.

DENSITY ALTITUDE: Issues are expected at times with high
temperatures near 100 today and Sunday.

WINDS: Light and variable will become south to southeast this
evening at around 5 to 8 kts.


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 10 PM MDT Sunday for Central and
Southeast Phillips-Central and Southern Valley-Daniels-Dawson-
Eastern Roosevelt-Garfield-McCone-Northern Phillips-Northern
Valley-Petroleum-Prairie-Richland-Sheridan-Southwest Phillips-
Western Roosevelt-Wibaux.

Red Flag Warning from 4 PM to 10 PM MDT Saturday for Northern
Valley and Northern Phillips Counties-Southern Petroleum and
Southern Garfield Counties-The Little Rockies-The Lower Missouri
River Breaks including the Charles M Russell National Wildlife
Refuge.

&&

$$

weather.gov/glasgow