textproduct: Great Falls

KEY MESSAGES

- It will be warm and mostly dry across the lower-elevations through Wednesday with a brief cooldown to end the work week.

- Today through Thursday there will be periods of snow in the mountains of North-central, Central, and Southwestern Montana with the heaviest snow expected Tuesday morning through Wednesday morning.

- Winds will increase each day through Tuesday with strong winds remaining through at least Wednesday.

UPDATE

/Issued 814 PM MST Sun Jan 4 2026/

Ample moisture ahead of troughing just off the Pacific coast will allow for a mix of rain and snow to continue this evening and tonight, mainly along the Continental Divide. Latest guidance was used to adjust to latest trends, otherwise no mentionable changes to the forecast this evening. -AM

DISCUSSION

/Issued 814 PM MST Sun Jan 4 2026/

- Meteorological Overview:

This afternoon there is an upper-level trough over North-central, Central, and Southwestern Montana. There is an embedded shortwave that will move through the upper-level flow this afternoon through this evening. This will bring another round of light snow to the mountains of North-central, Central, and Southwestern Montana on Sunday. On Sunday temperatures will remain warm across North-central, Central, and Southwestern Montana. Due to a strong surface pressure gradient and strong low and mid-level winds on Sunday it will be windy. Sunday evening through early Monday morning there is the possibility for rain to occur and then freeze in the Helena Valley. See the Forecast Confidence & Scenarios section for details. On Monday there is an upper-level ridge over North-central Montana. This will maintain the warm temperatures with windy conditions and light mountain snow. Monday night into Tuesday morning an upper-level shortwave will move over North-central Montana. This will bring strong winds to the Rocky Mountain Front and plains west of I- 15. On Tuesday there will be zonal flow over North-central, Central, and Southwestern Montana. Then Tuesday afternoon an upper-level shortwave will move through the upper-level flow. Due to strong mid and low-level winds and a strong pressure gradient. It will be windy on Tuesday. On Tuesday there will be cooler temperatures and mountain snow.

On Wednesday there will be zonal flow aloft with an upper-level shortwave moving through North-central, Central, and Southwestern Montana in the afternoon. This will keep cool but still above seasonal averages for temperatures across the area. Due to strong mid and low-level flow and a strong pressure gradient it will be windy on Wednesday. On Wednesday there will be mountain snow. On Thursday an upper-level trough moves over North-central, Central, and Southwestern Montana. This will cool down temperatures and bring mountain snow to the area on Thursday. Also due to strong mid and low-level winds and a strong pressure gradient it will be windy along the Rocky Mountain Front and plains west of I-15 on Thursday. On Friday and Saturday an upper-level ridge will move over North- central, Central, and Southwestern Montana. This will warm temperatures up with mostly dry weather. -IG

- Forecast Confidence & Scenarios:

Tonight through early Monday morning there is a 15 - 30% chance for rain to fall in the Helena Valley. If any rain does fall then there is a very high chance that it will freeze on roads, driveways and sidewalks.

From 6 AM Monday through 6 AM Thursday there is a 80% chance for 6 inches of snow or greater across the Rocky Mountain Front and West Yellowstone area in Southwestern Montana. From 11 AM Tuesday to 11 AM Wednesday there is a 60% chance for 6 inches of snow or greater along the Rocky Mountain Front. Due to not a high enough probability for 9 inches of snow a Winter Storm Watch was not issued at this time.

On Sunday and Monday there is greater than a 90% chance for wind gusts of 55 mph or greater along the Rocky Mountain Front. On Monday there is a 30 - 50% chance for wind gusts of 55 mph or greater along the plains west of I-15. On Tuesday there is a 60 - 80% chance for wind gusts of 55 mph or greater along the plains west of I-15. On Tuesday there is greater than a 70% chance for wind gusts of 75 mph or greater along the Rocky Mountain Front. On Tuesday there is a 30 - 50% chance for wind gusts of 55 mph along the Montana 200/US Highway 87 Corridor between Great Falls and Lewistown. As a result High Wind Watches have been issued for the Rocky Mountain Front, plains west of I-15 and the lower-elevations of Cascade and Judith Basin Counties on Tuesday. On Wednesday there is greater than an 80% chance for wind gusts of 55 mph or greater along the plains west of I-15. On Wednesday there is greater than a 70% chance for wind gusts of 75 mph or greater along the Rocky Mountain Front. On Wednesday there is a 30 - 50% chance for wind gusts of 55 mph along the Montana 200/US Highway 87 Corridor between Great Falls and Lewistown. On Thursday there is a 30 - 50% chance for wind gusts of 55 mph or greater along the plains west of I-15. On Thursday there is greater than an 80% chance for wind gusts of 55 mph or greater along the Rocky Mountain Front. -IG

AVIATION

05/06Z TAF Period

Area remains under a WSW flow aloft with variable mid-high level clouds through the period. Moisture and an embedded weather disturbance moving through tonight will maintain areas of mountain snow, valley rain, and mountain obscuration near the the continental divide with a period of lower mid-level clouds and some mountain obscuration as well as a few widely scattered showers passing across central MT overnight. Overall VFR conditions persist at all terminals. Hoenisch/Ludwig

PRELIMINARY POINT TEMPS/POPS

GTF 58 35 47 30 / 0 10 10 10 CTB 49 29 41 26 / 10 0 0 0 HLN 53 28 43 25 / 10 30 20 40 BZN 52 28 44 24 / 0 10 20 40 WYS 37 24 33 20 / 60 50 60 70 DLN 50 27 43 25 / 10 20 10 10 HVR 57 26 40 23 / 0 10 10 0 LWT 56 31 47 25 / 0 10 10 20

TFX WATCHES/WARNINGS/ADVISORIES

High Wind Watch from Monday evening through Tuesday evening for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front.

High Wind Watch from Tuesday morning through Tuesday evening for Cascade County below 5000ft-Judith Basin County and Judith Gap.