Area Forecast Discussion

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Cold front this morning, then breezy and cool through Sunday. - High temperatures Sunday will be 10 degrees below normal with rain and snow showers possible in the west-central Idaho mountains.

- Showers Tuesday and Wednesday will bring additional precipitation, mainly to the mountains.

SHORT TERM /Through Monday Night/

Issued 317 AM MDT SAT JUN 6 2026 First of two north Pacific cold fronts was moving eastward across our Idaho zones during the night, marked only by some cloudiness and moderate west wind. The second cold front, due early this morning in eastern Oregon and later this morning in western Idaho, will be stronger, supported by a more energetic short wave trough aloft pivoting inland and through our CWA. Neither front has enough moisture for pcpn in our CWA, but instability under the cold core aloft will develop rain and snow showers along our northern CWA border late Saturday night and Sunday morning. After temporary clearing later Sunday the next North Pacific cold front will move rapidly onto the northwest coast Sunday night. Clouds will increase overnight into Monday morning with showers spreading eastward across our CWA later Monday and Monday night.

LONG TERM /Tuesday through Saturday/

Issued 317 AM MDT SAT JUN 6 2026 Tuesday will finally bring measurable rain to our CWA after more than a month of dry weather, as a well-defined cold front moves eastward across our zones supported by a deep upper low coming inland across WA. The low will move across northern ID Tuesday night and into MT Wednesday. This track will continue cool, showery, and frequently windy weather in our CWA, with snow as low as 4500 feet MSL in the central Idaho mountains Tuesday. Total pcpn through Thursday should be .25 to .75 inch in Idaho north of the Snake Basin and in eastern Baker County/OR, with .05 to .25 inch elsewhere, including the Snake Basin in ID. Least pcpn (around .05 inch) is expected in central and northern Malheur County/OR. Snow may accumulate an inch in eastern Valley County and northern Boise and Elmore Counties above 5000 feet. As the upper low exits Wednesday another weaker low will follow in quickly behind it, maintaining the cool, showery wx into Thursday, at least on the Idaho side. After that low exits Thursday night our CWA will begin a warming and drying trend that will last through at least next weekend.

AVIATION /18Z Saturday through Sunday/

Issued 1237 PM MDT SAT JUN 6 2026

VFR with increasing low-to-mid clouds beginning this afternoon. After 06z/Sun, scattered to numerous rain and snow showers near KMYL. Snow levels 5-6 kft during precip. Mountains obscured in precipitation and low ceilings. Surface winds: NW 10-15 kt, widespread gusts to 20 kt. Gusts up to 30 kt in the MUO to TWF/JER corridor this afternoon. After 00Z/Sun, W-NW gusts 25 to 35 kt move SE from KBKE through the Snake River Plain overnight. Winds aloft at 10kft MSL: W/SW 15-30kt.

KBOI...VFR. Increasing low-to-mid clouds after sunset. Surface winds: NW 15kt, gusting 25 kt.

Sunday Outlook...VFR. Scattered low-to-mid clouds through late morning. Gusty W-NW surface wind 15-30 kt in the Snake Basin and south to NV border. Scattered rain/snow showers and local mountain obscuration in the West-Central Idaho mountains.

BOI WATCHES / WARNINGS / ADVISORIES

ID...Fire Weather Watch from Sunday afternoon through Sunday evening for IDZ424-426. OR...None.