textproduct: Pocatello

KEY MESSAGES

- Marginal Severe Risk Sunday Evening: A SPC Marginal Risk covers most of eastern Idaho today. Warm afternoon temperatures in the upper 70s to lower 80s combined with strong wind shear will support scattered thunderstorms capable of strong to severe downburst wind gusts (4050+ mph) late Sunday afternoon and evening.

- Breezy Southerly Winds Today: Southerly winds of 15 to 25 mph with gusts of 30 to 40 mph will develop this afternoon ahead of the primary convective line.

- Labor Day Cooldown: Highs on Labor Day Monday will drop significantly into the 60s for most locations, followed by the coldest night of the week Monday night as valley lows fall into the 40s and high country basins drop into the 30s.

- Pleasant & Seasonal Mid-Week Recovery: High pressure and dry air return Tuesday through Friday, lifting temperatures back to seasonal norms in the upper 70s and lower 80s before the next trough approaches next weekend.

DISCUSSION

Issued at 212 AM MDT Sun Sep 6 2026

Early morning satellite imagery shows the stagnant Pacific Northwest upper-level low finally making eastward progress across Oregon. Banded cloud cover and showers continue to stream around the eastern flank of the system, maintaining active weather over the Central Mountains early this morning. High- resolution convective-allowing models (CAMs) indicate mountain showers will taper off around or shortly after sunrise, yielding a brief mid-day lull across the forecast area.

This lull will be short-lived as the parent low advances closer to Idaho. Strong dynamic lift and surface heatingpushing valley highs into the upper 70s and lower 80swill yield sufficient instability and kinematics for organized convection. The Storm Prediction Center (SPC) maintains a Marginal Risk across much of eastern Idaho for strong to severe thunderstorm wind gusts. Most daytime hours will remain pleasant with increasing clouds, as convective development holds off until after 5:00 or 6:00 PM. Southerly surface winds ahead of the main line will increase to 1525 mph with gusts reaching 3040 mph. Convective activity will persist through the evening and early overnight hours before diminishing toward Labor Day morning. While the overall storm system has trended drier compared to earlier model runs, localized heavy downpours remain possible beneath stronger convective cores.

Labor Day Monday will be markedly cooler behind the cold front, with daytime highs capped in the 60s across most valley locations, though a few spots near the Utah border may briefly touch the lower 70s. Showers will wane by Monday afternoon, leaving dry but cool conditions for the evening. Clear skies and cold advection Monday night into Tuesday morning will result in the coldest temperatures of the week, with high country basins dropping into the 30s and lower elevation valleys falling into the 40s. Tuesday will be pleasant, dry, and seasonably cool.

Temperatures moderate rapidly back toward seasonal averages on Wednesday, with valley highs returning to the upper 70s and lower 80s. High pressure and general zonal upper flow will keep conditions mostly dry and uneventful through Friday, though isolated higher-terrain showers cannot be entirely ruled out as short-range hi-res guidance may better resolve subtle impulses. The next potential for widespread precipitation arrives next weekend as global models track an upper-level trough southward out of Western Canada. However, considerable ensemble spread remains regarding the depth, track, and associated surface impacts of this feature.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 923 PM MDT Sat Sep 5 2026

A few showers will continue around SUN most of the night. Little to no impacts expected. Expect a few gusts to 25 kts at PIH/IDA tomorrow afternoon with the potential for storms after 23z.

FIRE WEATHER

Issued at 212 AM MDT Sun Sep 6 2026

Scattered thunderstorms arriving late this afternoon and evening present the primary operational hazard today. Strong convective downdrafts capable of producing erratic wind gusts exceeding 4050 mph will be possible across all dispatch zones after 5:00 PM. Ambient southerly wind gusts of 30 to 40 mph will also develop this afternoon ahead of the storms. Wetting rains will accompany stronger storm cores tonight before drier, much cooler air arrives on Labor Day. High relative humidity recoveries are expected Monday night as temperatures drop into the 30s and 40s, followed by a warm, dry trend mid-to-late week.

PIH WATCHES/WARNINGS/ADVISORIES

None.