textproduct: Great Falls

KEY MESSAGES

- Warm and dry conditions will continue through Friday.

- The addition of gusty winds will lead to elevated to critical fire weather conditions on Friday afternoon.

- Cooler and wetter conditions arrive Saturday and last through the weekend with rain changing to snow at all elevations on Saturday.

UPDATE

/Issued 805 PM MDT Wed Oct 7 2026/ No significant changes to the forecast this evening. Grids just updated towards current trends. Mostly clear skies later this evening will allow for a cool night for most. Temperatures rebound quickly on Thursday for another warm afternoon.

It remains warm on Friday, along with low humidity and windy west winds ahead of a strong cold front. The fire weather watch will continue for Friday. The cold front is likely to be through much of North Central MT by 7 AM Saturday morning and through much of Southwest MT by mid day Saturday. Generally expect falling temperatures through the day on Saturday, with rain changing to snow within a few hours of frontal passage. Winter statements will likely be needed for portions of the CWA for this event. Brusda

DISCUSSION

/Issued 805 PM MDT Wed Oct 7 2026/

- Meteorological Overview:

Upper-level ridging will persist over the next couple days allowing for the continuing trend of warm and dry conditions across the region through Friday. Starting Friday afternoon, the ridge starts to break down and southwesterly flow aloft starts to increase as an upper-level trough approaches. Surface-level winds will increase through the peak mixing hours combining with warm temperatures and low relative humidity to produce elevated to critical fire weather conditions across much of Central and Southwest Montana through the evening hours.

Friday night, the upper level low begins to move south over the Olympic peninsula, cutting off from a dominant band of high- latitude westerlies. This will transition the upper level flow over Montana from being relatively zonal to southwesterly, as the low forms a positively tilted trough elongating from northern California through northeastern Washington this weekend. Friday night into Saturday morning, a cold front and associated low pressure will build and move south from the Canadian Rockies, eventually settling broadly over the Great Basin and Northern Great Plains, as high pressure moves back in towards North-Central MT. This high pressure to the north will create northerly flow, which combined with the cold front will usher in a cooler airmass through the weekend. This cooler air will allow for high temperatures to drop into the 30s/low 40s Sunday, with the mountains only seeing highs in the 20s/low 30s. The combination of broad WSW flow and the airmass regime sets the stage for what may be the first significant, widespread-impactful snowfall of the season late Saturday through early next week. - Dzomba

- Forecast Confidence & Scenarios:

See FIRE WEATHER for details on the upcoming fire weather concerns for Friday.

Winter Weather This Weekend: The colder, drier air feeding in from the northern high pressure gives increased confidence of low- elevation snow, especially between the Rocky Mountain Front and the Highwoods towards the Canadian border. There is also moderate confidence in the snowfall totals driven by the initial cold frontal surge. However, the combination of the wide baroclinic zone with uncertain upper level details, plus local enhancement from upsloping, leave ample opportunity for locally higher/lower amounts, and result in broad high/low end probabilities for the late Saturday through Sunday period. In addition, the upper level low may get cut off completely instead of elongating, which gives the forecast overall low confidence. -Dzomba

AVIATION

08/06Z TAF Period.

VFR and dry conditions prevail through the TAF period. Winds remain on the lighter side throughout the TAF period. High clouds begin to increase towards the end of the TAF period. -Wilson

FIRE WEATHER

Warm and dry conditions will continue through Friday with poor overnight RH recovery expected. While generally light winds are expected Wednesday and Thursday, gusty winds are expected Friday afternoon ahead of an approaching cold front. Sustained winds out of southwest at 15 to 25 mph with gusts up to 40 mph are possible. Combined with minimum RH values in the low to mid teens and high temperatures in the upper 70s to low 80s, the fire weather concerns for Friday afternoon are high. Thus the decision was made to issue a Fire Weather Watch for portions of Central Montana on Friday afternoon. Folks should take precautions to avoid outdoor burning if possible and be mindful of any actions that could create a spark.

Fire weather conditions will quickly ease Friday night into Saturday morning as much cooler and wetter conditions arrive across the region. -thor

PRELIMINARY POINT TEMPS/POPS

GTF 43 78 52 79 / 0 0 0 0 CTB 41 74 50 71 / 0 0 0 0 HLN 42 78 47 81 / 0 0 0 0 BZN 38 76 42 81 / 0 0 0 0 WYS 27 71 32 70 / 0 0 0 0 DLN 40 76 41 79 / 0 0 0 0 HVR 37 74 46 81 / 0 0 0 0 LWT 43 75 50 81 / 0 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

Fire Weather Watch Friday afternoon for Central and Eastern Lewis and Clark National Forest Areas-Helena and Townsend Ranger Districts of the Helena National Forest.