textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Dry and very warm this week, with record or near record highs expected at many locations.

- A minor disturbance late today will bring a low chance of showers and thunderstorms with gusty outflow winds along the Idaho/Nevada border.

- Much cooler and breezy with a chance of showers starting this weekend.

SHORT TERM /Through Wednesday Night/

Issued 359 AM MDT MON OCT 5 2026 High pressure will remain over the West through the period, bringing unseasonably warm temperatures each day. Highs in the lower valleys will reach the mid to upper 80s, with 70s to lower 80s in the mountains. This will place high temperatures at or near record highs in many locations, around 15 to 20 degrees above normal. See the latest Public Information Statement for details. Dry air and mostly clear skies will allow for good radiational cooling at night, but lows will still be 5 to 10 degrees above normal. Conditions will be mostly dry through the period. However, a weak shortwave trough will move east across northern Nevada late today, bringing a 10-20% chance of showers and thunderstorms to areas along the Idaho/Nevada border. With dry air in place, the main threat from any showers or storms will be gusty outflow winds to 40 mph. Otherwise, winds will be mostly light through the period. Finally, areas of smoke can be expected near prescribed burns, mainly in the mountains and near Burns, Oregon.

LONG TERM /Thursday through Monday/

Issued 359 AM MDT MON OCT 5 2026 The ridge will remain overhead through Friday, keeping temperatures 10 to 20 degrees above normal under mostly clear skies. Winds will start to pick up on Friday across the higher terrain as an upper level trough approaches from the north. The trough will push a cold front through the area on Saturday, bringing cooler temperatures and breezy conditions. Highs are forecast to cool by 10 to 15 degrees from Friday, but ensemble variability in the timing of the front reduces confidence in the temperature forecast for Saturday. The trough is favored to deepen over the Pacific Northwest, and may move overhead as a closed low. This will continue the cooling trend on Sunday and Monday, with highs decreasing another 10 to 15 degrees. A chance of precipitation will develop especially east of the low with a 20-40% chance of rain and high mountain snow across central/south central Idaho, and a 10-20% chance further west. Winds will remain breezy under this pattern.

AVIATION /12Z Monday through Tuesday/

Issued 602 AM MDT MON OCT 5 2026 VFR. High clouds moving overhead today, decreasing tonight. Areas of smoke and haze may reduce visibility near prescribed burns. Isolated showers and thunderstorms late this afternoon and evening south of KTWF. Surface winds: variable less than 12 kt. Winds aloft at 10kft MSL: SW-W 5-15 kt.

KBOI...VFR with periods of high clouds. Surface winds: SE around 5 kt, becoming NW by mid-afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.