textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Continued warm, dry days through Friday. Near record high temperatures.

- Valley rain and mountain snow along an eastward-moving cold front Friday night and Saturday morning. Additional rain and mountain snow, along with cooler temperatures, next week.

- Breezy winds through Sunday, strongest in Harney County Friday afternoon.

SHORT TERM /Through Saturday Night/

Issued 240 AM MST THU NOV 12 2026 A highly amplified upper level ridge will be centered near the Continental Divide today while a deep upper level low from the eastern Pacific approaches the coast. This will keep southerly flow in place today, continuing mild, near-record warm temperatures and dry conditions. Skies will be partly to mostly sunny with passing high clouds. Winds will be breezy once again, strongest through the Snake Basin and across portions of eastern Oregon where gusts will reach 15-30 mph. Similar conditions can be expected through Friday afternoon, except winds will increase as the low begins to move onshore. Expect gusts 35-50 mph across open areas of southeast Oregon and far southwest Idaho, strongest in remote areas of southern/western Harney County Oregon. Elsewhere, expect gusts 20-40 mph.

A cold front will enter central Oregon Friday afternoon and move east across our area Friday night, bringing widespread precipitation. This system will be quick-hitting and weaken as it moves inland, with precipitation ending from the west late Friday night through Saturday morning. Rain amounts of 0.05-0.25 inch will be common across southeast Oregon and the lower elevations of southwest Idaho, with 0.20-0.50 inch across the mountains. Snow levels will be above 7000 feet initially and only fall to 6000-7000 feet behind the cold front, limiting accumulating snow to higher mountains. Winds will decrease behind the front but gusts 15-30 mph will persist into Saturday, strongest in the Magic Valley. Highs Saturday will be 10-15 degrees cooler in most areas, but still several degrees above normal. An upper level ridge will begin building overhead on Saturday as the system moves east.

LONG TERM /Sunday through Thursday/

Issued 240 AM MST THU NOV 12 2026 A series of low pressure systems from the eastern Pacific will move into the western US through the extended period. The first will approach the coast on Sunday, then split with the bulk of the energy slowly progressing inland over the Southwest Monday and Tuesday. Dry and breezy conditions will continue on Sunday ahead of this system with southwesterly flow increasing temperatures several degrees from Saturday. The trough will hold together enough for a 50-70% chance of light precipitation late Sunday through Tuesday. Snow levels will fall from 5500-6500 feet Sunday night to 4000-6000 feet by Tuesday, lowest across eastern Oregon. Temperatures will cool a few degrees each day with lighter winds. After brief dry conditions, another low will enter the Pacific Northwest from the Gulf of Alaska mid to late week. This low may contain colder air than previous systems, but confidence in the low progression and extent of cold air is low due to model variability. With the uncertainty, precipitation chances rise to 30-50% late Wednesday through Thursday, with temperatures favored to cool a few more degrees to near normal and snow levels around 3500-5000 feet.

AVIATION /12Z Thursday through Friday/

Issued 453 AM MST THU NOV 12 2026 VFR under thin high clouds today. Local LLWS mostly near the Snake River from KONO-KMUO. Surface winds: E-S 5-15 kt with gusts up to 25 kt in portions of the Snake Plain and SE Oregon. Winds aloft at 10kft MSL: S-SW 15-25 kt.

KBOI...VFR. Surface winds variable less than 8 kt this morning, resulting in LLWS as winds off the surface remain SE around 30 kt. Surface winds becoming SE 8-15 kt starting this afternoon, with a brief period of light and variable winds this evening.

Weekend Outlook...Mainly VFR through Friday, then a cold front will bring rain and high mountain snow Friday night into Saturday morning. Low VFR-MVFR in rain, IFR-LIFR and mountain obscuration in snow. Snow level 6500-7500 ft MSL. Decreasing low to mid clouds and dry late Saturday through early Sunday, then rain increasing across SE Oregon late Sunday. Surface winds: on Friday, S-SE 10-25 kt with gusts 25-40 kt, except lighter across E-central Oregon and W-central Idaho. On Saturday, SW-NW 5-15 kt with gusts 15-30 kt, strongest in the Magic Valley. On Sunday, E-S 5-15 kt with gusts up to 25 kt in portions of the Snake Plain and SE Oregon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.