916
FXUS65 KGGW 170810
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
210 AM MDT Sun Aug 17 2025

.DISCUSSION...

KEY MESSAGES:
- There is a marginal risk for severe thunderstorms south of the
  Missouri River today and tonight and Monday across the entire
  region.

- A building ridge will push temperatures to near 100 or higher
  Tuesday and Wednesday.


WEATHER PATTERN OVERVIEW:

SW flow aloft will prevail today and Monday with waves in the flow
aloft. The waves will interact with unstable airmass to allow for
chances for showers and thunderstorms at times. A marginal threat
for severe weather will be south of the Missouri River today and
tonight and across the entire region on Monday.

Upper ridge will peak over Montana on Tuesday and Wednesday.
Temperature forecast continues to climb in the guidance with some
areas near 100 for highs on Tuesday and many areas above 100 for
highs on Wednesday. With low temperatures for Tuesday night also
remaining in the mid to upper 60s, the likelihood of needing
extreme heat products for Tuesday and Wednesday is becoming
likely. Current forecast highs for Tuesday and Wednesday are near
the NBM 50 percent right now and the NBM 90 is near 110 for highs in
many areas on Wednesday.

A cold front Wednesday night and Thursday will bring much cooler
temperatures for Thursday and Friday.

FORECAST CONFIDENCE & DEVIATIONS:
Main forecast deviation from the NBM was for Monday`s pops where
the current NBM dropped pops below 15% in most areas which is a
disconnect with SPC marginal risk. Went with 20 pops in most
areas.

Confidence is high that there will be isolated to scattered
showers and thunderstorms at times today and tonight.

Low confidence in thunderstorm chances on Monday.

Confidence is high in very hot temperatures on Tuesday and
Wednesday which will exceed 100 degrees in some areas.

&&

.AVIATION...

LAST UPDATED: 0815Z

FLIGHT CAT RANGE: VFR

DISCUSSION: There will be mid and high clouds at times today and
tonight mixed in with periods of mostly clear skies. Isolated
showers and thunderstorms are possible today with isolated to
scattered showers and thunderstorms possible tonight.

Some of these storms have a chance (5-10%) to become severe with
and damaging winds. Any storm that occurs could briefly drop
visibility to MVFR(3-5SM) levels.

WIND: Variable less than 10 knots today and tonight. Gusty and
erratic wind will be possible near any thunderstorm.

&&

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

$$

weather.gov/glasgow