textproduct: Great Falls

KEY MESSAGES

- Scattered showers will continue through the afternoon along the Rocky Mountain Front and across the Hi-Line.

- Warmer and drier on Wednesday and Thursday.

- Cooler and wetter conditions return on Friday and last through the weekend.

DISCUSSION

/Issued 1210 AM MDT Tue Sep 8 2026/

- Meteorological Overview:

A shortwave trough will make its way across the region through the day continuing the chances for showers along the Rocky Mountain Front and across the Hi-Line. There is a chance for some isolated to scattered thunderstorms this afternoon, although the threat for severe weather is low.

By Wednesday, upper-level flow becomes a bit more zonal to northwesterly, allowing for temperatures to warm up. This effect is briefly enhanced on Thursday as weak transient ridging moves through which will allow for lower elevation locations to reach the upper 70s to mid 80s.

The next system is expected to arrive Thursday evening into Friday with cooler and wetter conditions expected to last through the weekend.

- Forecast Confidence & Scenarios:

Scattered showers will continue, primarily along the Rocky Mountain Front and across the Hi-Line through the rest of the morning with isolated to scattered thunderstorms possible this afternoon. These storms are not expected to be severe but they may produce locally heavy rain which may continue some of the flooding concerns for areas that have already received a lot of rain.

With regards to the system this weekend, there is a chance for mountain snow, primarily above 7000 feet. Confidence in amounts above 4 inches is low but there is currently a 60% chance for at least 2 inches of snow in the mountains Sunday morning. The main concern will be for those recreating in the backcountry where difficult conditions are expected Friday through Sunday. -thor

AVIATION

08/12Z TAF Period

A mix of low VFR to IFR conditions will continue across the plains terminals (KGTF, KCTB, KHVR, KLWT) as rain continues to fall across North Central Montana early this morning before rain tapers to showers and then winds down this afternoon. Winds will remain gusty through this afternoon as low pressure exits the area to the east. For Southwestern terminals (KBZN, KEKS, KWYS, KHLN), expect mainly VFR conditions with just a few passing showers. Winds will be gusty here as well, but should top out around 15-20kts.

For KGTF: While rain should largely remain north of KGTF through most of the morning, a few light rain showers will still occasionally bring some MVFR to IFR conditions. Westerly (240-270 degrees) winds to 25kts through 2z will keep crosswinds over 15kts through most of the daylight hours on Tuesday. Ludwig

HYDROLOGY

An areal flood watch will continue for the east side of Glacier Park, Browning, Cut Bank and Shelby areas into Tuesday. Periods of steady rain continue to affect this area, with most locations receiving between 2 and 3 inches of rainfall already in this area. An additional inch of rainfall is possible through Tuesday morning. Thus some minor flood impacts could develop later today or into Tuesday morning. Brusda

PRELIMINARY POINT TEMPS/POPS

GTF 63 43 76 53 / 70 10 0 0 CTB 60 43 69 50 / 90 0 0 0 HLN 68 42 77 49 / 10 0 0 0 BZN 68 38 78 44 / 20 0 0 0 WYS 63 29 69 31 / 0 0 0 0 DLN 68 39 77 45 / 0 0 0 0 HVR 63 42 75 48 / 90 30 0 0 LWT 65 41 74 50 / 30 10 0 0

TFX WATCHES/WARNINGS/ADVISORIES

Flood Watch until noon MDT today for East Glacier Park Region- Eastern Glacier, Western Toole, and Central Pondera-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Northern High Plains-Southern High Plains-Southern Rocky Mountain Front.