textproduct: Pocatello

KEY MESSAGES

- Dry and Milder Sunday: After patchy morning low stratus near Island Park and Bear Lake clears, today brings dry, partly cloudy weather between systems with afternoon highs rebounding roughly 5 degrees over Saturday's readings.

- Rain and snow slowly moves into the central mountains Monday, then spreads east through Tuesday: Snow levels begin at 6,5008,000 feet before dropping to 5,0006,500 feet on Tuesday as colder air chases exiting moisture. Expect accumulating snow down to around 6,000 feet and impactful accumulations above 7,000 feet, while lower valleys may see non-accumulating snowflakes but the forecast remains fluid.

- Colder & Unsettled Mid-to-Late Week: Broad Pacific Northwest troughing will restrict valley highs to the upper 30s and lower 40s from Tuesday into next weekend, accompanied by daily light snow chancesincluding potential valley floor snow if meaningful moisture overlaps the colder air.

DISCUSSION

Issued at 305 AM MST Sun Nov 15 2026

Early morning satellite imagery shows mainly clear skies across eastern Idaho, though localized pockets of low stratus have developed up around Island Park and in the far southeastern corner near Bear Lake. The region resides between departing and incoming upper-level troughs today, allowing dry conditions to return under partly cloudy skies once morning stratus erodes. Increasing sunshine and weak ridging will enable afternoon temperatures to rebound by roughly 5 degrees compared to Saturday's readings. The next Pacific low-pressure system will begin slowly pushing inland tonight and Monday. Model guidance continues to trend slower with the eastward progression of this trough, keeping the first half of Monday dry for most locations and confining incoming afternoon moisture primarily to the Central Mountains. Cloud cover and afternoon precipitation will knock daytime temperatures down a couple of degrees across the Central Mountains and south-central Idaho on Monday, while areas farther east experience little to no change from Sunday's highs.

The storm system finally swings across Idaho Monday night through Tuesday night, though guidance continues to show a pronounced trend toward splittingsimilar to Saturday's system. This split-flow evolution introduces notable uncertainty and keeps forecast confidence low regarding specific, definitive rain and snow totals. Current National Blend of Models (NBM) QPF guidance depicts general liquid totals up to 0.20 inches across the Snake River Plain, Magic Valley, and low-to-mid elevation mountain valleys. In favored upslope areasincluding the Wood River Valley, surrounding Central Mountains, and along the Montana bordertotals are pushing 0.50 inches, with a similar pattern extending from the South Hills and Albion Mountains eastward through the Bear River Range. Higher elevations across the remaining mountain ranges are projected to receive 0.25 to 0.35 inches.

Ahead of the main frontal passage, snow levels will hold between 6,500 and 8,000 feet before colder air overspreads all of eastern Idaho on Tuesday. Tuesday's lower-elevation snow potential will come down to a classic race between cold air advection arriving and precipitation tapering off on the back side of the departing low. During this frontal transition, snow levels are forecast to drop to between 5,000 and 6,500 feet. The lower bound of model guidance brings snow levels low enough for snowflakes to fall on valley floors, though surface temperatures will make accumulation difficult. That all being said, there remains considerable uncertainty with this part of the forecast. GFS and its ensembles are noticeably snowier at lower elevations compared to those with the ECMWF. Overall, higher confidence exists with snow down to around 6,000 feet, while impactful accumulations remain confined above 7,000 feet but things will remain in flux for a few more forecasts in all likelihood.

The mid-to-late portion of next week will remain cool and unsettled as broad upper-level troughing anchors over the Pacific Northwest and ejects periodic waves of embedded moisture across the Intermountain West. Persistent cold air will restrict daytime valley highs to the upper 30s and lower 40s from Tuesday straight into next weekend, accompanied by daily chances for light snow. While substantial ensemble spread remains regarding how individual waves evolve late next week, the colder thermal profile means that if organized moisture overlaps with these temperatures, accumulating snow down to valley floors is certainly possible.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 305 AM MST Sun Nov 15 2026

VFR expected through the period with only some mid/high level clouds and light winds. The region resides between weather systems so things will be quiet today but clouds will be on the increase towards the latter portion of the current forecast period ahead of our next system. There remains a low-end chance of some low stratus/fog at sites but probability is quite low and is not mentioned in the forecast at this time.

PIH WATCHES/WARNINGS/ADVISORIES

None.