textproduct: Glasgow

KEY MESSAGES

- A warming trend will continue into Memorial Day. Highs could be approaching 100 degrees in some locations on Tuesday. - Hot temperatures, low humidity, and gusty southeast winds will raise fire weather concerns for Tuesday.

- Scattered thunderstorms are expected by Tuesday evening moving in from west to east, with an isolated stronger storm possible. Expect chances for showers and thunderstorms to continue at times for the second half of the week.

DISCUSSION

WEATHER PATTERN OVERVIEW:

Temperatures will continue to heat up across NE Montana heading into Memorial Day thanks to an upper ridge pattern. High temperatures by Memorial Day will be well into the upper 80s to mid 90s for most of NE Montana while relative humidity reaches as low as 12 to 15 percent. However, wind is expected to be light during this time, limiting the fire weather threat.

On Tuesday as the ridge will shift over to the east, low level southeast winds will ramp up. High temperatures will be in the 90s to near 100 with humidity readings between 10 and 20 percent. This combination in the presence of dry fuels will likely raise fire weather concerns. Even where green up is underway, curing may take place from consecutive hot and dry weather days. Gusty southeast winds may also present boating hazards for Fort Peck Lake. Future shifts can assess the need for any heat/lake/fire weather related headlines as confidence continues to improve.

On Tuesday evening, an upper trough will move in from the west while thunderstorms will across central Montana. These storms will make progress eastward into NE Montana. An isolated stronger thunderstorm is certainly possible, with the greatest coverage expected to be for areas west of a line through OPheim to Glasgow to Jordan.

Wednesday through Friday will continue to feature a deep trough across the western CONUS and a ridge to the east. NE Montana will be sandwiched in between with thunderstorm chances each day, especially in afternoon and evening hours. Some of the storms have the potential to be on the stronger side and may produce brief heavy downpours.

FORECAST CONFIDENCE & DEVIATIONS:

NBM was largely used for the forecast period. Pops were however adjusted in the near term for Tuesday for consistency and to best reflect thunder chances. Confidence is certainly growing on hot, dry, and windy conditions on Tuesday leading to heat, fire weather, and lake wind concerns, as well as convective potential later in the day. Confidence is more moderate for the thunderstorm coverage later in the week given the later time scales involved, but there is decent ensemble consensus in the overall synoptic pattern.

AVIATION

LAST UPDATED: Sunday May 24, 2026 at 1915Z.

FLIGHT CAT RANGE: VFR.

DISCUSSION: Excellent flying weather looks to continue with mid to high clouds moving across the terminals at times.

WIND: West at 5 to 15 kts, with a few gusts to 20 kts through this evening. Winds will become light and variable after 03Z.

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

GGW WATCHES/WARNINGS/ADVISORIES

None.