textproduct: Great Falls

KEY MESSAGES

- Warm, dry, and breezy through the weekend.

- Elevated to critical fire weather conditions possible across Central and Southwest Montana through the weekend.

- Reduced air quality at times from regional wildfires.

UPDATE

Late afternoon update has been published, with the main adjustment being to lower high temperatures over the plains where areas of smoke and the passage of a boundary earlier in the afternoon has held temperatures back throughout the day. This update will help diurnal trends into the evening given the "cooler" starting point. Otherwise the remainder of the forecast remains on track, with no other adjustments needed. - Moldan

DISCUSSION

/Issued 534 PM MDT Thu Aug 6 2026/

- Meteorological Overview:

As the upper-level ridge continues to move east it will start to flatten out allowing hot and dry conditions to persist across the region. Winds will pick up during the peak mixing hours of the afternoon, especially across Southwest Montana which will increase fire weather concerns through the weekend. Quasi-zonal flow will stick around through the middle of next week with some passing weak shortwaves possible starting on Monday which may come with a low chance for light precipitation.

- Forecast Confidence & Scenarios:

Wildfire Smoke:

Smoke from wildfires across the PacNW and Montana will continue to impact air quality for our region, especially in Southwest Montana where an Air Quality Alert is currently in effect. For most of Central and North-Central Montana significant reductions in air quality are not currently expected but could be enough to impact those who are the most sensitive. Those who are particularly sensitive to reduced air quality should limit time outdoors and take preventative measures to ensure their safety.

Hot, Dry, Breezy Friday/Saturday:

Above normal temperatures will continue through the next week but the hottest temperatures for this forecast period are expected on Friday and Saturday with highs reaching into the upper 90s for some locations. Similarly, very dry conditions are expected to persist through the weekend across the region which will lead to enhanced to critical fire weather concerns (detailed in the FIRE WEATHER section).

Precipitation Chances Next Week:

Over the course of the next week a few weak passing shortwaves may provide a chances for precipitation but there is still significant deviation in the models on how these waves will play out and whether or not there is even much of a chance for wetting rainfall. It will be something to watch as any amount of precipitation would be welcomed but even if these showers trend on the wetter side it will likely be little relief to the bigger picture of our fire weather concerns through the next week. -thor

AVIATION

07/00Z TAF Period

VFR conditions will prevail for all terminals throughout this TAF period, with slant range visibilities slightly reduced due to smoke from regional wildfires. Winds will remain generally light and variable, with westerly winds increasing at KGTF and the southwest terminals around 19Z. -Dzomba

For KGTF: Between 03Z-09Z there is a 10-20% chance of easterly crosswinds exceeding 15 kts. Winds will then remain generally light and variable, with westerly winds increasing to around 7-9 kts by 20Z.

FIRE WEATHER

The highest probability for critical fire weather conditions will be in FWZ 116 and 118 including the southern portion of Lewis and Clark county, Broadwater, eastern Jefferson, and northwestern Gallatin counties. Minimum RH values in the single digits to low teens are possible on Friday and Saturday with poor overnight RH recovery expected across the zone. On top of that, gusty winds are expected through the afternoon and evening hours on both days with highs in the mid to upper 90s expected.

FWZ 117 is where borderline elevated fire weather conditions meet some of the higher probabilities for reaching critical fire weather conditions. The Meagher county portion of the zone looks to remain elevated to critical through both Friday and Saturday. Conversely, the Cascade and Judith Basin county portions of FWZ 117 are much more likely to reach elevated to critical conditions on Saturday as opposed to Friday. But Friday cannot be totally ruled out for Cascade and Judith Basin based on what is being observed in the latest model runs. As a result, the decision was made to include FWZ 117 in the Fire Weather Watch for both Friday and Saturday.

Further north, for FWZ 114 and 115, there is a potential for elevated fire weather conditions but confidence in the stronger winds was too low to include it in the watch. These areas will be watched carefully with future updates as changes to the forecast will impact the threat level and probability of reaching critical fire weather conditions.

While Friday and Saturday remain the main focus of the Fire Weather Watch, Sunday could also be an elevated fire weather day. Minimum RH values and high temperatures are not expected to be as critical on Sunday but there could be some gusty winds at times for portions of Southwest and Central Montana. At this time it is too early to determine the exact threat level for Sunday but it will be something to watch with future forecast updates. -thor

PRELIMINARY POINT TEMPS/POPS

GTF 51 90 56 94 / 0 0 0 0 CTB 47 86 53 88 / 0 0 0 0 HLN 54 95 57 95 / 0 0 0 0 BZN 52 95 55 96 / 0 0 0 0 WYS 43 89 45 89 / 0 0 0 0 DLN 52 92 54 92 / 0 0 0 0 HVR 51 88 54 92 / 0 0 0 0 LWT 52 87 55 90 / 0 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

Fire Weather Watch from Friday afternoon through Saturday evening for Central and Eastern Lewis and Clark National Forest Areas-Helena and Townsend Ranger Districts of the Helena National Forest-Lincoln Ranger District of the Helena National Forest.