606
FXUS65 KGGW 311639
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
1039 AM MDT Thu Jul 31 2025

.DISCUSSION...
KEY MESSAGES:

1) Patchy fog will be brurning off this morning.

2) Scattered thunderstorms are possible south of the Missouri
River mainly this evening.

3) The region will be on the west side of a weak ridge, showers
and thunderstorm opportunities will continue into early next week.

WEATHER PATTERN OVERVIEW:
A weak upper ridge with a relaxed jet stream will keep mesoscale
winds from the east, with some drying northeast winds remaining
over the northeast portion of the CWA. A few showers will pass
through near the Yellowstone River early this morning, and then by
noon a few isolated thunderstorms will slowly develop in this same
area. By late afternoon, a weak shortwave will allow some strong
thunderstorms to develop along the southern fringes of the area.
There is low (30 percent) confidence an isolated severe wind and
hail storm will move through Petroleum county this evening.
Popcorn thunderstorms are expected to develop across most of the
area from south to north tonight and continue into Friday. WPC has
the area outlined for marginal excessive rainfall for Friday and
Saturday since there will be very little wind shear to push storms
around, and precipitable water values are very high for this time
of year.

This monsoonal pattern will linger through early next week while
the area maintains near seasonable temperatures.

FORECAST CONFIDENCE & DEVIATIONS:
There is generally low confidence of severe thunderstorms
occurring today, and high confidence on monsoonal moisture
reaching northeast Montana tonight.

Increased winds through midnight tonight with two parts NBM 90 and
one part NBM.

&&

.AVIATION...
Expected Flight Category: VFR.

Discussion:
There is low confidence (10% chance)
of visibilities dipping into MVFR through 18Z due to some isolated
pockets of smoke.

A few weak showers and thunderstorms will move in from the south
by early afternoon for KSDY and KGDV. There is moderate to high
confidence all TAF sites will experience scattered storms this
evening into the overnight. There is low confidence (10% chance)
of visibilities dipping into MVFR through 18Z due to some isolated
pockets of smoke.

Wind: East 7 to 18 knots. Gusty and shifting winds near
any thunderstorms.


&&

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

$$

weather.gov/glasgow