textproduct: Glasgow

KEY MESSAGES

- Warm and dry conditions are expected the next few days, peaking on Wednesday. - Fire weather concerns return Wednesday. - The forecast becomes potentially windier and wetter Wednesday night into the weekend with scattered showers and isolated thunderstorms possible.

DISCUSSION

WEATHER PATTERN OVERVIEW: As a weak cold front passes through the area amid already dry and gusty conditions, there are isolated showers and thunderstorms forecast to occur between 4 PM and 9 PM. Some of the CAM models suggest severe gusts around 60 mph are expected to mix down, enhancing the synoptic gusts already around 50 mph. An upper ridge builds into the area on Tuesday with lighter winds and dry weather. A few random locations may reach criteria for red flag conditions on Tuesday in the east, but there is marginal evidence for this set up thus far.

On Wednesday the upper ridge axis moves through eastern Montana with the warmest day of 2026 so far expected. Some locations will likely have highs in the 90s with increased dry southerly flow, adding to ongoing fire weather concerns. A trough moves through Thursday and keeps winds elevated through at least Friday. This situation will be monitored closely for high wind and extended fire concerns.

A more zonal flow pattern develops thereafter to moderate temperatures some and bring smaller synoptic ridge/trough couplets embedded in it. This will bring chances for showers and thunderstorms at times across the region through the weekend with possible wetting rains or even a marginal severe potential depending on whether it matches up with peak heating. Individual ensemble members continue to disagree on what day/time any given ridge/trough couplet moves through though.

FORECAST CONFIDENCE & DEVIATIONS: The main deviations were to lower humidity and increase winds through Wednesday based on high confidence in a dry pattern with fire weather concerns that the NBM has not been fully capturing lately.

There is high confidence on isolated to scattered showers and thunderstorms occurring through 9 PM today. There is very high confidence for fire and lake wind headlines being needed Wednesday, and in temperatures reaching the lower 90s for many locations. There is moderate confidence on a high wind and fire products being needed into Thursday and Friday as well. Confidence is low on Wednesday evening for thunderstorms being strong to severe as the trough moves through.

AVIATION

LAST UPDATED: 0200Z

FLIGHT CAT RANGE: VFR

DISCUSSION: Dry conditions and mainly clear skies are expected tonight through Tuesday.

WIND: Mainly NW and 10 to 20 kts gusting up to 25 kts this evening. Slowly decreasing to around 10 kts after sundown into Tuesday.

EQUIPMENT: No obs from KSDY. TAF will be AMD NOT SKED until obs return.

/GAH

GGW WATCHES/WARNINGS/ADVISORIES

Lake Wind Advisory until 9 PM MDT this evening for Central and Southeast Phillips-Central and Southern Valley-Garfield-McCone- Petroleum.