textproduct: Great Falls

KEY MESSAGES

- Critical fire weather conditions continue through the rest of the day due to warm, windy, and dry conditions.

- A mostly dry cold frontal passage will bring well below normal temperatures for Monday.

- Drier conditions through the week with a gradual warm-up in temperatures through Friday after Monday.

DISCUSSION

/Issued 1250 PM MDT Sun Aug 2 2026/

- Meteorological Overview:

With the upper-level troughing still passing through the area, windy conditions still persist through the rest of the day as decent 700mb winds aloft linger. A secondary wave moving through the area overnight into Tuesday will push a boundary south across North- Central MT. This brings along another wave of windy conditions with winds of 30-45 mph and very light precipitation. This boundary will also help usher in cooler temperatures for Monday. Monday's temperatures are expected to be well below normal across the region, with lower elevation highs only reaching mid 60s to lower 70s. Higher mountain peaks are forecasted to drop into the 30s Monday morning. Therefore, they could see light flurries if they receive any appreciable precipitation.

Northwest flow aloft settles in through mid week as another upper- level ridge builds in across the Western U.S. This ridge will slowly move to the east and into the area through the week. As a result, temperatures gradually warm to back above normal during the second half of the week. There is not much moisture associated with the ridge, so precipitation chances remain low through the week and any amounts will be little if an area receives rain. Wildfire smoke will continue to affect the region this week. North winds help push out a good chunk of smoke across North-Central MT Monday and Tuesday into Southwest MT. -Wilson

AVIATION

03/00Z TAF Period

VFR conditions will prevail across all terminals during this TAF Period outside of the KCTB, KHVR, and KGTF terminals. At the KHVR and KCTB terminals smoke will reduce visibility to at least MVFR- levels for the first few hours of this TAF period before it moves southward. At the KGTF, KHLN, and KLWT terminals there is a low chance for smoke to briefly reduce visibility to MVFR levels at around 03/06Z. A cold front is sliding south from Canada during the beginning of this TAF Period and will shift winds from westerly to more northerly. It will be windy across all terminals during this TAF Period. At the KGTF, KHVR, and KCTB terminals MVFR-level ceilings will occur for a few hours around 03/12Z. Across all of the TAF sites smoke from wildfires will reduce slantwise visibility during the duration of this TAF Period. -IG

For KGTF: Winds shift to northwesterly between 03 and 06Z associated with a surface cold front and remain northwesterly through this forecast period. Prior to 16Z there is an 80% chance for a 15 kt crosswind. After 16Z there is a 20% chance for a 15 kt crosswind. Increased humidity in the 0C to-10C layer will result in at least brief/minor icing concerns by early Monday morning. -IG/Ludwig

FIRE WEATHER

Critical fire weather conditions are expected through the rest of the day across all fire weather districts. Although cooler temperatures are forecast today, very low relative humidity will persist. This combined with gusty winds will lead to critical fire weather conditions. A cold front will move through the area this evening into early Monday morning and bring a sharp wind shift from westerly to more northerly. Winds will increase to 30 to 45 mph during this wind shift. To account for the wind shift and increase in winds behind the boundary, the Red Flag Warning was extended through 3am Monday.-IG/Wilson

PRELIMINARY POINT TEMPS/POPS

GTF 49 71 45 78 / 10 10 0 0 CTB 44 66 41 74 / 10 20 0 0 HLN 50 73 47 79 / 10 10 0 0 BZN 49 73 42 79 / 10 0 0 0 WYS 39 72 34 76 / 0 0 0 0 DLN 46 73 42 77 / 0 0 0 0 HVR 48 71 42 79 / 10 10 0 0 LWT 46 65 41 73 / 20 20 0 0

TFX WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 3 AM MDT Monday for Central and Eastern Lewis and Clark National Forest Areas-Chouteau and Fergus Counties-Eastern Glacier/Toole/Central/Eastern Pondera/Liberty- Helena and Townsend Ranger Districts of the Helena National Forest-Hill and Blaine Counties-Lewis and Clark National Forest Rocky Mountain District-Rocky Mountain Front-Lincoln Ranger District of the Helena National Forest.