textproduct: Great Falls

KEY MESSAGES

- Breezy conditions across Southwest Montana on Friday with a chance for afternoon showers and thunderstorms.

- Cooler temperatures and more widespread precipitation is expected over the weekend into early next week.

DISCUSSION

/Issued 227 AM MDT Fri Sep 4 2026/

- Meteorological Overview:

Southwesterly flow aloft will persist over the region with an upper- level trough positioned over the west coast. This will bring daily chances for afternoon showers and thunderstorms through Saturday, primarily along the Continental Divide. Through the weekend into early next week, the trough nudges a little to the east with more directly moisture flow over the region combined with a shortwave trough ejecting out on Monday providing a chance for widespread precipitation to the region. Temperatures will cool through early next week before warming back up slightly in late next week as upper- level ridging tries to redevelop in the wake of the trough.

- Forecast Confidence & Scenarios:

Rain Sunday through Tuesday:

The Hi-Line still has the highest confidence for higher rainfall amounts with Southwest Montana still favored for lower rainfall amounts. The main area of uncertainty is the portion of Central Montana south of line between Great Falls and Lewistown and north of Townsend where the models are flip-flopping on whether or not these locations will get some of the heavier precipitation or not. For the time being there is 70% confidence in at least 0.50" rainfall along the northern half of our region with a 40% probability for at least 1.0" of rain. For the southern half of our region there is a 60% chance for at least 0.10" of rain and only a 30% for greater than 0.50" of rain over the 2 day period. It is worth mentioning these are broad probabilities for the region and localized heavier rain is possible for both the northern and southern portions of the region. -thor

AVIATION

04/12Z TAF Period

Expect generally VFR conditions to prevail across North Central and Southwestern Montana over the 04/12z TAF period, with RA generally expected to remain west of the Continental Divide, though a few may drift to KCTB after 9z Saturday. Winds will generally be modest, with a few areas of wind gusts to 20-25 kts across SW MT and along the Continental Divide.

For KGTF: Westerly winds are expected to prevail today, with winds generally from 250-280. While sustained winds will generally stay below 10 kts, a few gusts to 15-20 kts will result in crosswinds near 15 kts between 20z and 1z. Wind gusts should dip below 15kts after 1z, ending the threat of crosswinds over 15k kts. Ludwig

PRELIMINARY POINT TEMPS/POPS

GTF 76 48 74 48 / 0 20 10 30 CTB 68 44 64 44 / 10 70 60 60 HLN 76 48 75 49 / 10 30 30 20 BZN 80 45 81 45 / 0 0 0 0 WYS 69 35 72 34 / 0 10 0 0 DLN 75 41 78 41 / 0 10 10 0 HVR 82 48 81 50 / 0 10 0 40 LWT 83 47 78 48 / 0 0 0 10

TFX WATCHES/WARNINGS/ADVISORIES

None.