textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Isolated to scattered showers today, greatest coverage northern mountain zones. minor snow accumulations above 6000 ft MSL.

- Gradual clearing this evening. With temperatures around 5 degrees below normal through Wednesday.

- Dry and warmer Thursday, precipitation chances increasing Friday into the weekend.

SHORT TERM /Through Thursday Night/

Issued 114 AM MDT TUE OCT 27 2026 Isolated to scattered showers will continue today as a secondary wave and weak cold front cross over the area, especially this afternoon with daytime heating aiding in destabilization. The highest coverage of showers will fall over our northern mountain zones (30-60%), and eastern Oregon (10-20%). Chances in SW Idaho are under 10%, but a shower here or there isn't out of question. Weak instability this afternoon will allow showers to take on a convective nature, with rain and graupel at lower elevations and isolated lightning flashes possible (chances less than 10%). Snow levels this afternoon will range from 4.5-6.5 kft MSL, increasing from northwest to southeast. Showers will linger in our northern zones tonight, tapering off through Wednesday. Areas of clearing tonight will allow for areas of fog development, especially in sheltered mountain valleys; this threat will repeat itself each night through the short-term period. Temperatures this afternoon and next will be in the 50s in the Snake Plain, 40s in the Oregon high desert, higher Idaho basins, and mountain valleys. A cooling trend in overnight lows will set in, with lows Thursday morning near 30 degrees throughout lower elevations and 10-20 degrees in the Oregon high desert and higher Idaho basins.

Thursday will be dry across the area with increasing southwesterly flow ahead of the next system. With a more southerly component in the flow, temperatures Thursday afternoon will be around 5 degrees warmer than that of today and Wednesday.

LONG TERM /Friday through Tuesday/

Issued 114 AM MDT TUE OCT 27 2026 As the next trough approaches our area Friday, precipitation chances will begin to increase across higher terrain in SW-Idaho Friday afternoon. This will ring true come Saturday afternoon, except precipitation chances will continue to increase through the day Sunday (mainly across southwest Idaho) as the trough and it's associated cold front cross the area. The southwesterly flow aloft will keep snow levels at 5-7 kft MSL (rising as you move from west to east). This should keep the majority of snow accumulations above 6kft MSL (a 30-50% chance of exceeding 2 inches of snow Saturday afternoon through Sunday, chances increasing with elevation). While snow levels lower following the frontal passage, this will also be about the time precipitation begins tapering off. The area will dry out Monday as upper level ridging builds in behind the departing trough. Dry conditions will prevail through the beginning of next week. Seasonable or below normal temperatures will continue through the long-term period.

AVIATION /12Z Tuesday through Wednesday/

Issued 506 AM MDT TUE OCT 27 2026

Generally VFR, except patchy fog and areas of low stratus early this morning. Mountains obscured. Scattered rain/graupel and mtn snow showers returning Tuesday morning. Low VFR to IFR in showers. Snow levels: 4500-6000ft MSL. Surface winds: Variable 5-15 kt. Winds aloft at 10kft MSL: W-SW 15-25 kt.

KBOI...Generally VFR. Scattered rain/graupel showers returning to the area between Tue/21Z and Wed/03Z. Surface winds: SE 3-8 kt this morning, shifting to NW 3-8 kt after Tue/19Z.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.