textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Dry with gradually warming temps through Monday morning. Frost and/or freezing temps in agricultural valleys Sunday morning.

- Light rain and mountain snow Monday afternoon through Tuesday morning.

- Cooler again Tuesday.

SHORT TERM /Through Monday Night/

Issued 204 PM MDT SAT OCT 24 2026 Coldest air occurred this morning with high pressure at the surface under northwesterly flow aloft. Temps will now gradually moderate through Monday as the next deep Gulf of Alaska upper low approaches. Low temps tonight will be 15 to 25 degrees in eastern OR and the higher basins in ID, and mid 20s to mid 30s elsewhere in ID. Highs Sunday will be in the 50s to mid 60s, or 5 to 8 degrees warmer than today. Lows Sunday night will be mid 20s to mid 30s in the mountains and mid 30s to lower 40s in the valleys. Highs Tuesday will drop back to the upper 40s through 50s. The upper low will reach the OR coast by Monday morning and change flow aloft to southwesterly over our CWA. Latest models it inland across OR later Monday and across the northern part of our CWA Monday night and Tuesday with light rain and mountain snow, mainly over northern areas. Total precipitation will be lighter than with the previous storm, generally .25 to .50 inch in northern areas and .10 to .25 inch in southern mountains, but less than .10 inch in southern valleys. However, this storm will be colder than the previous one, and a dusting to 3 inches snow accumulation is expected in northern areas above 4500 feet Monday night through Tuesday morning. Winds will gradually increase Sunday through Monday, becoming west or southwest 15 to 25 mph Monday afternoon, strongest on the Oregon side.

LONG TERM /Tuesday through Saturday/

Issued 204 PM MDT SAT OCT 24 2026 Strong agreement among ensemble members that an unsettled and active weather pattern will set up over the region during most of next week. While exact details remain to be seen, there is strong agreement that a period of seasonably cool and moist conditions will accompany this pattern change. Guidance suggests that temperatures will be in the mid to upper 50s which is near normal for late October. Mean precipitation values for the period are around 0.2 inches for lower valleys, 0.5 inches for mountain valleys, and greater than 0.6 inches for higher terrain. Snow levels are expected to be between 5000 to 6000 feet, allowing for some early season snow accumulation.

AVIATION /06Z Sunday through Monday/

Issued 1125 PM MDT SAT OCT 24 2026

VFR. High clouds increasing. A 10% chance of overnight fog in sheltered valleys, limited by high clouds. Surface winds: E to SE 5- 15 kt. Sunday afternoon gusts around 20 kt for KBKE and KBOI-KMUO. Winds aloft at 10kft MSL: S to SW 5-20 kt.

KBOI...VFR. High clouds increasing. Surface winds: SE 5-12 kt. Occasional gusts around 15-20 kt after Sun/17Z.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.