textproduct: Great Falls

KEY MESSAGES

- Hot and drier conditions are expected for the weekend.

- Hot, breezy, and dry conditions will bring elevated to near critical fire weather conditions Saturday and Sunday to Southwest MT.

- Temperatures slightly cool next week with increasing chances in thunderstorms.

DISCUSSION

/Issued 556 PM MDT Fri Jul 10 2026/

- Meteorological Overview:

The upper level ridge will continue to build in hot temperatures through the weekend across the region. Current forecasted temperatures peak into the mid 90s to low 100s across the lower elevations Saturday through Monday with overnight lows in the upper 50s to mid 60s and some isolated upper 60s. The ridge will help keep the area drier overall through the weekend. However, a few waves of vorticity maximums combined with enough mid level relative humidity bring a low end chance for isolated showers and a thunderstorm or two, particularly for this evening and Sunday. Strong vertical mixing and very dry surface layer will make any shower or storm capable of producing gusty winds. Increasing 700mb winds Saturday and Sunday will bring increasing west to southwest winds. The combination of hot, dry, and breezy conditions will bring elevated fire weather conditions Saturday and Sunday with near critical conditions to Southwest MT.

Heading into next week, the ridge will still be dominant through at least mid week. Monsoonal moisture advects in and daily disturbances look to return daily chances for showers and thunderstorms. Precipitation should help moderate temperatures next week, but will remain very warm. With PWATs nearing or exceeding an inch next week, we will have to monitor the potential for strong to severe thunderstorms and localized flash flooding with storms, but exact details remain uncertain.

- Forecast Confidence & Scenarios:

Below are the probabilities for maximum temperatures reaching or exceeding 100F this weekend: Sat 7/11 Sun 7/12 Great Falls 70% 50% Bozeman 0% 70% Helena 50% 50% Havre 70% 60% Cut Bank 0% 0% Lewistown 20% 80% Dillon 0% 30%

Heat Advisories remain in effect from Saturday afternoon through Monday evening across North-Central and parts of Southwest MT. Heat risk impacts peak on Sunday, but ensembles have been trending hotter for Saturday afternoon. We will continue to monitor the heat risk heading into the weekend for any increase in impact, especially across Central MT. -Wilson

AVIATION

11/06Z TAF Period

Prevailing VFR conditions throughout the area for the period but some isolated showers are moving northeast between KBTM and KHLN as well as a thunderstorm along the Rocky Mountain Front though there is uncertainty if it will hold together once over the plains. Elevated winds are expected for Saturday afternoon after 18Z for most terminals seeing between 20KT - 25KT gusts. Hot temperatures this weekend will raise pressure/density altitudes especially for the higher elevation airfields impacting aircraft performance. - Akins

FIRE WEATHER

The combination of hot, dry, and breezy conditions Saturday and Sunday will bring elevated fire weather concerns particularly in Southwest MT where stronger day time mixing can produce wind gusts of 30 to 40 mph. Near critical conditions are possible south of the I-90 corridor, where wind speeds are the highest. The Hot, Windy and Dry Index show a 0.60 to 0.80 probability for reaching the 90th percentile on Saturday, with a bigger footprint of probabilities on Sunday. The Hot, Windy, and Dry index Sunday show 0.40 to 0.60 probabilities for reaching the 95th percentile in Southwest MT. These conditions will aid in the drying/curing of fuels. A fire weather watch has been issued for Montana FWZ110, FWZ111, and FWZ123 for Sunday as a result. -Wilson

PRELIMINARY POINT TEMPS/POPS

GTF 58 100 61 99 / 20 0 0 0 CTB 56 91 58 91 / 20 10 0 0 HLN 59 100 63 99 / 20 0 0 0 BZN 56 98 61 102 / 20 0 0 0 WYS 46 91 49 95 / 20 0 0 0 DLN 53 95 56 99 / 20 0 0 0 HVR 59 102 62 102 / 10 0 0 0 LWT 56 98 59 102 / 20 0 0 10

TFX WATCHES/WARNINGS/ADVISORIES

Heat Advisory from noon Saturday to 9 PM MDT Monday for Bears Paw Mountains and Southern Blaine-Canyon Ferry Area-Cascade County below 5000ft-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Fergus County below 4500ft-Gallatin Valley- Gates of the Mountains-Helena Valley-Hill County-Judith Basin County and Judith Gap-Madison River Valley-Missouri Headwaters- Northern Blaine County-Southern High Plains-Western and Central Chouteau County.