textproduct: Pocatello

KEY MESSAGES

- Quiet & Unseasonably Warm Through Friday: Abnormally warm October weather continues with clear skies, light winds, and zero precipitation chances through the end of the workweek.

- Breezy Saturday Shift: Winds will increase on Saturday as a regional pressure gradient tightens ahead of an approaching trough, with rain chances spreading southwest to northeast during the afternoon and evening.

- Cutoff Low & Tropical Moisture Surge (SundayMonday): Models are trending toward a cutoff low over central California and Nevada tapping into tropical moisture from the remnants of TC Rachel. This setup could bring widespread heavy rain of 0.50" to 1.50" in lower valleys and eastern highlands, and 0.25" to 0.75" in the central mountains but some uncertainty remains

- Fall Cooldown & Mountain Snow: Temperatures drop well below normal starting Sunday, marking a likely end to late-summer- like warmth. While lower-elevation valley snow looks less likely, higher-terrain snowfall remains expected.

DISCUSSION

Issued at 109 PM MDT Wed Oct 7 2026

Afternoon satellite imagery shows virtually no cloud cover across eastern Idaho as quiet and abnormally warm October weather continues. A stable synoptic regime will maintain this pattern through the end of the workweek, with only subtle day- to-day temperature fluctuations and no appreciable chances for precipitation. Daytime highs will run well above seasonal climatological norms, accompanied by light winds and clear overnight skies.

Weather conditions begin to transition drastically on Saturday as a potent upper-level trough approaches the Intermountain West. Surface winds will pick up noticeably during the day as the regional pressure gradient tightens. Increased cloud cover and wind mixing will initiate a cooling trend, though daytime maximum temperatures will still manage to hold a few degrees above seasonal averages across most valleys. Cloud cover and precipitation probabilities will increase rapidly during the second half of Saturday, spreading from southwest to northeast.

A major airmass change overspreads eastern Idaho for the second half of the weekend into early next week, dropping temperatures well below seasonal normals. Operational models have trended toward consolidating a cutoff low over central California and Nevada Sunday into Monday, though ensemble guidance maintains minor variance regarding the final track.

Assuming this cutoff solution materializes, a moist southerly- to-southwesterly flow will become locked over eastern Idaho, maintaining persistent precipitation through early next week. Adding to the precipitation potential will be an influx of tropical moisture from the remnants of Tropical Cyclone Rachel. This rich moisture tap supports widespread heavy precipitation across much of eastern Idaho, with current QPF forecasts calling for 0.50 to 1.50 inches across lower-elevation valleys and the eastern highlands, and 0.25 to 0.75 inches across the central mountains. While some uncertainty remains regarding the exact track and timing of the cutoff low and thus precip amounts - confidence is very high in a prolonged transition to a cool, wet autumn pattern likely signaling an end to our late-summer- like weather for the season. Below-normal temperatures and periodic rain and mountain snow showers will persist well into next week. Lower-elevation valley snow looks less likely with this iteration of the forecast, but higher-terrain snowfall remains expected. Forecast updates will continue to refine snow levels and QPF totals as guidance converges over the coming days.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1118 AM MDT Wed Oct 7 2026

Light winds and VFR skies continue into Thursday.

FIRE WEATHER

Issued at 109 PM MDT Wed Oct 7 2026

Dry conditions with above normal temperatures continue into Friday. Overnight humidity recovery may be poor especially at higher elevations. Winds begin to increase late Friday in response to breakdown of the upper ridge as the next system approaches East Idaho. Higher elevations may approach critical conditions with very dry humidities and gusty winds. Right now the conditions look marginal, so no headlines are anticipated. Temperatures begin to slide Saturday as cloud cover and precipitation increase through the day. Winds remain breezy, but humidities increase, limiting critical conditions. MUCH cooler temperatures arrive by Sunday with widespread precipitation. Snow will be possible above 8000 ft across the central mountains and along the Divide. Cool temperatures and unsettled conditions continue into mid week next week.

PIH WATCHES/WARNINGS/ADVISORIES

None.