textproduct: Pocatello

KEY MESSAGES

- Light snow will spread across East Idaho tonight and continue through Tuesday night. Winter driving conditions are expected, especially over mountain passes.

- Daytime highs Tuesday in some lower elevations may limit snowfall accumulation potential, and snow may mix with rain in some areas.

- The next winter storm arrives Friday and continues into the weekend, bringing mountain snow and low elevation rain and snow.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 126 PM MST Mon Dec 1 2025

Satellite imagery shows broad area of stratus across East Idaho beginning to be overtopped by moisture moving in ahead of shortwave crossing the Seattle/Vancouver area this afternoon. Seeder-feeder light snows may begin late this afternoon and evening ahead of main precipitation where the low clouds still persist, but early accumulations due to this should remain very light. High-res models remain consistent on timing of bringing light snow into areas along the Montana border including Island Park this evening, then slowly expanding precipitation across the remainder of East Idaho tonight into Tuesday. Given the northwest flow aloft, the bulk of the precipitation through the event should be focused across the eastern and southern highlands, with some shadowing expected across northwest portions of the Snake Plain. Temperatures daytime Tuesday could be warm enough across the Magic Valley and Raft River regions to support a brief mix of rain/snow during the afternoon, and will limit accumulation potential further north in the Snake Plain. Total accumulations remain similar to previous forecast cycle, generally up to an inch for most of the Snake Plain (lower in the Magic Valley), trending toward 2-3" north toward Monida Pass and Ashton Hill. Highland areas east of I-15 see accumulations rise to 4-6" with locally higher amounts at and above pass level. Further west, lesser accumulations are forecast for the central mountains, especially for areas shadowed in northwest flow. To the south highlands between I-84/I-86 and the Utah border, most of the accumulation will be above valley floors, with most mountain ranges seeing 3-5" for the event. Given these amounts, winter headlines will NOT be issued, but motorists could expect winter travel conditions at times through at least Tuesday night.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 126 PM MST Mon Dec 1 2025

Will start out dry on Wednesday behind the Canadian system as it pushes east. It will be cool with highs in the upper 20s to mid 30s. Going into the latter part of the week the model blends indicate getting into a moist more zonal flow. With that expecting several waves of precipitation late Thursday through Sunday. There will be the potential for mountain snowfall accumulation in this flow pattern. We are likely to see substantial warming late week into the weekend and early next week. By Saturday snow levels will likely rise to the 6 thousand foot level so will likely see some rain in lower elevations with the late week and weekend precipitation. Grids indicating the heaviest snow in the eastern mountains near Wyoming border Friday through Sunday. At least a low chance some areas above 6 thousand feet could see 6 inches but extremely high uncertainty with any timing and precipitation amounts that far out into forecast period. Friday through Monday expect high temperatures in the 40s in low elevations and 30s to around 40 in the mountains.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1026 AM MST Mon Dec 1 2025

Main impact will be fog and stratus into early afternoon with LIFR conditions at SUN but expect improvement by 20Z. BYI and PIH expected to remain VFR this afternoon. Kept the IFR to MVFR conditions at IDA until 23Z and at DIJ through 21Z. Low confidence in how quickly the lower ceilings dissipate this afternoon. A system dropping south from the northwest will likely bring lower ceilings and snow after 18z Tuesday to most sites.

PIH WATCHES/WARNINGS/ADVISORIES

None.