textproduct: Pocatello

KEY MESSAGES

- Unseasonably Warm & Dry Through Friday: High pressure centered over the Great Basin will maintain quiet conditions and light winds, boosting lower-elevation highs 7 to 12 degrees above normal into the upper 50s and lower 60s.

- Cooler Saturday with Passing Moisture: An initial Pacific moisture wave arrives late Friday night and continues Saturday, dropping highs into the 40s alongside scattered rain and mountain snow showers.

- Winter Pattern Shift Next Week: An expansive Western U.S. trough anchors over the region early next week, bringing below-normal temperatures and daily precipitation chances, with snow potentially reaching valley floors during overnight and early morning hours by mid-week.

DISCUSSION

Issued at 115 AM MST Wed Nov 11 2026

The weather pattern across eastern Idaho will remain generally benign through the workweek, characterized by an absence of high-impact systems and continued above-normal temperatures. Early morning satellite imagery shows mid-to-high level cloudiness streaming over the region, but tranquil weather will persist beneath high pressure anchored over the Great Basin. Strong atmospheric subsidence and rising 500 mb heights will promote unseasonably warm afternoons, with daytime highs running 7 to 12 degrees above seasonal averages. Lower-elevation valleys across the Snake River Plain and Magic Valley will comfortably reach the upper 50s to lower 60s under light, terrain-driven winds, providing very pleasant late-autumn conditions.

The tranquil synoptic pattern begins to break down heading into the weekend as an upper-level trough over the Gulf of Alaska taps into Pacific moisture and ejects shortwave energy across the Pacific Northwest. An initial wave of moisture and an associated surface cold front will move into eastern Idaho late Friday night and persist through much of Saturday. Thickening cloud cover and precipitation will suppress daytime heating, holding Saturday high temperatures mainly in the 40s across the region.

The second half of the weekend offers a brief lull between systems. Eastern Idaho will reside in between moisture surges on Sunday, allowing precipitation to taper off and keeping conditions predominantly dry. Afternoon temperatures will rebound slightly under partly cloudy skies, running a touch warmer than Saturday.

A much more pronounced and prolonged pattern shift takes hold to kick off next week. Global deterministic guidance and ensemble clusters remain in strong agreement regarding broad upper-level troughing anchoring over the western United States. This setup will usher in an expansive cold air mass, making below-normal temperatures increasingly likely along with daily chances for scattered rain and mountain snow across eastern Idaho. Depending on the depth of cold air advection, snow levels could reach valley floors toward the tail end of the forecast period, particularly during overnight and early morning hours. While considerable ensemble spread remains regarding specific precipitation amounts and timing this far out, confidence is high in a transition to colder, unsettled weather.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 544 AM MST Wed Nov 11 2026

VFR conditions through the period with mainly clear skies and light winds. No precip is expected.

PIH WATCHES/WARNINGS/ADVISORIES

None.