textproduct: Glasgow

KEY MESSAGES

- The warm up will continue over Memorial Day Weekend, with highs in the upper 80s to mid 90s by Monday and Tuesday of next week. - Hot temperatures, low humidity will raise fire weather concerns for Monday and especially Tuesday when gusty southeast winds develop.

- Look for scattered thunderstorms by Tuesday evening moving in from west to east, with an isolated stronger storm possible.

DISCUSSION

WEATHER PATTERN OVERVIEW:

Upper ridging will build in from the west over the Memorial Day Weekend. This ridge will allow temperatures to warm each day, cresting with highs in the upper 80s to mid 90s on Monday and Tuesday. It would not be surprising to see an isolated location see highs into the upper 90s in deeper valley locations especially. These hot temperatures will be accompanied by low relative humidity and may raise fire weather concerns. This is especially true on Tuesday when southeast gusty winds develop as the ridge axis slides to the east. These strong winds may also present Lake Wind concerns for Fort Peck Lake.

As a trough approaches from the west, this will set off chances for thunderstorms to develop across central Montana that will track into NE Montana by Tuesday evening, which may also be accompanied by shifting, gusty winds and/or a hail thread, brief downpours, and lightning.

FORECAST CONFIDENCE & DEVIATIONS:

NBM was largely followed for the period with much of the greater impacts expected to arrive in days 4 and 5. Confidence is high on the warm up this weekend. Moderate confidence exists on the fire weather concerns for Monday and Tuesday due to green up of fuels, especially in the west. However, some curing may occur with several days of warm and dry weather given lack of recent precipitation, and fuels are still relatively dry in eastern fire weather zones. Meanwhile, confidence is increasing on more scattered thunderstorms on Tuesday afternoon and evening but it is not yet certain whether or not a few stronger storms may also develop given the later time scales. Once this moves into the day 2 to 3 period, high resolution model fixes will be able to better resolve details needed for a clear assessment.

AVIATION

LAST UPDATED: Friday May 22, 2026 at 1945Z.

FLIGHT CAT RANGE: VFR.

DISCUSSION: Mid level clouds continue over terminals this afternoon and likely will extend into the evening hours, though most places will remain dry.

WIND: NW at 10 to 15 kts will continue through 03Z, then becoming light and variable. Winds at times may trend toward an easterly direction at around 5-8 kts, especially near KGGW and KOLF overnight.

EQUIPMENT: KSDY obs are unavailable and will be AMD NOT SKED.

GGW WATCHES/WARNINGS/ADVISORIES

None.