428
FXUS65 KGGW 040637
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
1237 AM MDT Thu Jun 4 2026

.KEY MESSAGES...

- A new round of showers and thunderstorms is expected this
  afternoon and evening. There is a small chance one or two cells
  could become severe along the far south.

- Expect a slow warm up into Saturday with 80s and 90s for Highs.

- A second wave of showers and thunderstorms is expected Saturday
  night into Sunday.



&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:
A shortwave ridge will filter in this morning with partially
clear skies ahead of another shortwave trough this afternoon.
There is a good shot of thunderstorms occurring from west to east
starting around 8-9AM in the southwest and reaching the east by
around 3-6 PM. Some of the storms may produce heavy rainfall as
precipitable water will be around an inch or slightly higher.
Roughly a tenth of an inch of precipitation is expected for most
places that do get a hit, but higher totals could easily be
possible.

The next shortwave ridge bring dry and warmer weather on Friday.
Flow aloft turns southwest on Friday evening so showers are
expected to move in after 6 PM Friday. There is potential for
another hot day occurring on Saturday in the east depending on
the timing of a cold front that will likely move across the
region. There is a Day 3 severe weather outlook for the east part
of the area, so there is currently a marginal outlook for the
afternoon and evening hours.

More concerning will be a prolonged southwest upper flow that
sets up this weekend and deep into next week. This time of year
could mean higher than normal thunderstorms occurrences that could
be severe. Flash flooding is also possible with Precip Water near
or above an inch (normal is between 0.50-0.75"). There is low
certainty on how long this southwest flow will occur.

FORECAST CONFIDENCE & DEVIATIONS:
The only NBM deviation was a few hours of PoPs being interpolated
to improve trends slightly during the late morning hours tomorrow
as storms move into the west slowly.

There is MODERATE to HIGH confidence in showers occurring today
night, and HIGH confidence in scattered thunderstorms on
Saturday.

There is HIGH confidence in temperatures through Saturday, with
MODERATE confidence on temperatures from Sunday onward.

/GAH


&&

.AVIATION...
LAST UPDATED: 0630Z

FLIGHT CAT RANGE: VFR

DISCUSSION: A surface low northeast of the area is allowing mid to
near MVFR clouds to impact TAF sites as it exits. Some fog may be
able to build in along the Montana Canada border from 10 to 15Z
but should not reach the Terminals directly. A new round of
showers and thunderstorms is expected to impact the terminals in
the afternoon and evening today before exiting the area
overnight. Some of these storms may have erratic gusty winds.

WIND: Light and variable through tonight. Becoming W at 10 kts
or less after sunup through Thursday. Becoming light and variable
again Thursday evening. Erratic gusty winds will be possible near
any thunderstorm.

GAH



&&

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

$$

weather.gov/glasgow