713
FXUS65 KGGW 300647
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
1247 AM MDT Sat May 30 2026

.KEY MESSAGES...

- Periods of showers look to continue today with thunderstorms
  becoming more widespread by the late afternoon and evening
  hours. Some storms may be slow moving, producing heavy rainfall.

- Upper trough will maintain cool and wet weather conditions
  across NE Montana into early next week.

- The trough will push east with drier conditions and moderating
  temperatures by the middle of next week.


&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:

Periods of showers will continue at times today with
thunderstorms becoming more numerous during the afternoon and
evening hours. Overall, widespread wetting rains are expected from
the numerous showers and thunderstorms. HREF guidance is showing
3 hour max QPF on the order of 1-1.5" with the heaviest slow
moving convection this evening. The WPC maintains a slight risk of
excessive rainfall for western portions of the CWA for this
period.

The upper trough/closed low pattern will likely maintain wet and
cool conditions over the region into early next week, with high
temperatures for Sunday and Monday into the 60s for much of the
weather. This will come as a relief from the recent hot and dry
weather conditions across the area.

Ensembles show a general eastward progression of the trough such
that a shallow ridge builds in for the middle of the week. This
would allow drying conditions and moderating temperatures.


FORECAST CONFIDENCE & DEVIATIONS:

NBM was largely followed with a few exceptions. High temperatures
were modestly nudged lower for the next couple of days. This is
following the relatively recent warm bias in the NBM during the
hot weather conditions. There is some degree of uncertainty
whether or not this bias will persist with the pattern change.

Pops were also tweaked at times through the weekend for
consistency and collaboration.

Confidence is above average for wet weather conditions and
widespread wetting rains through early next week. While peak total
rainfall amounts will likely come in between 1.5" and 3" through
Monday, these may be isolated and confined to where slow moving
storms persist. The exact timing and placement of these storms is
difficult to pin down, but overall expect highest probabilities
west of Glasgow to Jordan with lower probabilities toward the
MT/ND border. Given dry conditions leading up to this event
flooding concerns are minimal, but will have to monitor low lying
areas, open fields, small streams, poor drainage areas
where slow moving thunderstorms with intense downpours occur.



&&

.AVIATION...

Updated: Saturday May 30, 2026 at 0545Z

FLIGHT CATEGORY: VFR to IFR. Brief IFR possible in intense
thunderstorm downpours Saturday evening.

DISCUSSION: Periods of showers will continue today, with
thunderstorms becoming more numerous in the evening hours. Some of
the storms may produce intense and persistent downpours.

WIND: East at 10 to 15 kts, gusting to 25 kts. Gusty and shifting
winds are possible with any storms.


&&

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

$$

weather.gov/glasgow