986
FXUS65 KGGW 170646
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
1246 AM MDT Fri Jul 17 2026

.KEY MESSAGES...

- Upper ridging will keep above average temperatures in place
  through the weekend. On Sunday, an isolated 100 degree
  temperature is possible in the Yellowstone River Valley.

- Look for the next chance for thunderstorms Friday evening into
  Friday night, with an isolated severe wind gust possible. Some
  storms may also produce heavy rainfall.

&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:

Upper ridging will continue to bring very warm temperatures to the
region through the weekend. Isolated triple digit heat is possible
in the Yellowstone corridor from Terry to Sidney.

Weak embedded shortwaves will continue to tap deep monsoonal
moisture to offer daily chances for thunderstorms. High
precipitable water values will mean any given storm could be a
prolific rainfall producer. In addition, the SPC has included the
western zones of Phillips and Petroleum Counties for today in a
marginal risk for severe thunderstorms.

FORECAST CONFIDENCE & DEVIATIONS:

A few minor adjustments to pops were necessary given recent
trends for showers and thunder early this morning across the
southern zones. Patchy fog was also added given the high humidity
and near saturated boundary layer beneath the ridge.


&&

.AVIATION...

UPDATED: Friday July 17 at 0645Z.

FLIGHT CATEGORY: VFR.

DISCUSSION: Dry weather conditions are expected through this
evening. Late tonight, isolated to scattered thunderstorms pushing
in from the west may lead to reductions in visibility.

WIND: East to southeast winds will prevail at 5 to 15 kts most of
the time with occasional gusty conditions near any thunderstorms.



&&

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

$$

weather.gov/glasgow