textproduct: Great Falls

KEY MESSAGES

- Hot and dry through the week, with heat peaking on Saturday.

- Wildfire smoke around most days.

- Isolated showers and thunderstorms most days this week, mostly across Southwest Montana.

UPDATE

Updated forecast is out. No significant changes, just updated towards current trends. A few isolated showers/thunderstorms are mostly affecting Southwest MT, mostly south of a line from Butte to Bozeman. These storms should diminish around Midnight. Lightning will be the main impact from any storm this evening.

Otherwise, generally hot afternoon temperatures expected the next several days, with Saturday looking to be the warmest day. Smoke will continue to impact much of the CWA for the next several days as well. Brusda

DISCUSSION

/Issued 200 PM MDT Mon Jul 27 2026/

- Meteorological Overview:

Upper level ridging across the central CONUS will allow for a persistent southwesterly flow aloft across the Northern Rockies this week. Wildfire smoke from Oregon, Washington and vicinity will more or less continue to be ushered into the region through the week, resulting in continued hazy/smoky skies. Temperatures do look to slowly trend warmer through the week, though there is some uncertainty as to how quickly the trend develops.

Weak waves progressing through the southwesterly flow aloft will yield the risk for a few afternoon showers and thunderstorms most days this week, mainly east of I-15 across Southwest Montana. These looks to produce little in way of precipitation, however.

The heat looks to peak on Saturday immediately ahead of the breaking down of the upper level ridge. As the ridge breaks down late Saturday into Sunday, breezy winds look to develop in most areas. This ridge breakdown looks to be completely dry, which raises concerns for fire weather, should the windier scenario unfold. -AM

- Forecast Confidence & Scenarios:

Temperatures this week:

Wildfire smoke will play a large role in just how quickly temperatures trend warmer this week across the region. Regardless, temperatures will be above average during the climatologically hottest portion of the year, which is notable. Those working outside this week should take extra care to mitigate impacts from both the heat and wildfire smoke.

Ridge breakdown this weekend:

Confidence remains high that a ridge breakdown will occur this weekend. Temperatures immediately ahead of this ridge breakdown look to trend even further above average Saturday before falling Sunday as breezier westerly winds ensue. The uncertainty with this system will be for the timing of the stronger winds aloft. They presently look to be timed to occur overnight, which would result in a slightly less breezy day (But certainly still breezy) into Sunday. Should the stronger winds aloft be delayed slightly, Sunday would trend much breezier. -AM

AVIATION

28/00Z TAF Period

Wildfire smoke from the Pacific Northwest will be the primary concern through the TAF period. Visibilities can drop down to MVFR at times due to the smoke across North-Central MT. Isolated showers and thunderstorms continue through 28/06z for mainly Southwest MT. Gusty winds will be possible with thunderstorms. There's a low end chance for another round of isolated showers and thunderstorms for Southwest MT Tuesday.

For KGTF: Winds will remain light and variable through Tuesday morning. By Tuesday afternoon, winds will prevail more out of the west. Probabilities for a 15kt crosswind remain low through the morning (10%), but it increases to 50% by 28/22z. -Wilson

PRELIMINARY POINT TEMPS/POPS

GTF 60 94 59 94 / 0 0 0 0 CTB 54 90 56 89 / 0 0 0 0 HLN 63 94 60 93 / 0 10 10 20 BZN 59 94 58 92 / 20 20 20 20 WYS 50 87 49 84 / 10 10 10 40 DLN 57 91 55 88 / 10 10 10 20 HVR 60 97 60 96 / 0 0 10 0 LWT 59 93 58 90 / 0 20 20 10

TFX WATCHES/WARNINGS/ADVISORIES

None.