textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Dry weather with warming temperatures through Sunday.

- Cooler Monday and Tuesday with gusty winds and an increased chance of showers and high mountain snow.

- Gulf of AK low will bring widespread precipitation Wednesday and Thursday. Accumulating snow is possible down to mountain valley floors with heavy snow possible above 6500 feet.

SHORT TERM /Through Sunday Night/

Issued 342 AM MDT FRI MAR 27 2026 Upper ridging will bring a return to above normal temperatures through the weekend. Today will see the biggest jump in temperatures (8-15 degrees) aided by easterly surface winds. A weak impulse tracking across central NV will increase high cloud cover on Saturday while temperatures warm another 3-8 degrees from today. Sunday brings little change with a mix of sun/clouds and temperatures steady at around 15 degrees above normal. An approaching upper trough will introduce a slight chance of showers across the e-central Oregon and w-central Idaho mtns north of Baker City-McCall-Yellowpine Sunday night.

LONG TERM /Monday through Friday/

Issued 342 AM MDT FRI MAR 27 2026 The shortwave trough and accompanying cold front cross the region on Monday, bringing a >60% chance of precipitation to the mtns. At lower elevations the focus of precipitation development is along the cold front and is currently covered by a 30-50% chance of showers. Tuesday remains unsettled as a weak trailing trough tracks through CA and into NV. Overnight deterministic models have backed off the precipitation threat for our area, especially across northern zones, but enough ensemble members are carrying precipitation to keep a broad 30-60% chance of rain and high mountain snow for Tue/Tue night. Of all the periods in the extended Tue/Tue night is the most uncertain. Models remain in good agreement that a GoAK low will kick through the Pac NW during the Wed-Fri time period. The chance for rain/snow is forecast to ramp up Wed/Wed night as the leading edge of the upper trough and a ribbon of deeper moisture crosses the region. Snow levels of 5500-7000 feet on Wednesday will drop to 3500-4500 feet by Thursday as precipitation transitions to mostly instability driven showers. Sites above 6500 feet MSL have the chance to see a heavy wet snowfall with this event, while mountain valleys could see light accumulations through Thursday. At lower elevations the cold air aloft will introduce the chance for graupel showers. Temperatures are at or above normal through Wednesday, dropping to around 5 degrees below normal for Thur/Fri.

AVIATION /12Z Friday through Saturday/

Issued 548 AM MDT FRI MAR 27 2026 VFR with scattered high clouds today, increasing in coverage by afternoon. Surface winds: E-SE 5-15 kt, with afternoon gusts 20-25 kt mainly over SE OR and KMUO-KJER-KTWF. Winds aloft at 10kft MSL: variable or SW less than 10 kt.

KBOI...VFR. Surface winds will be SE 6-10 kt with gusts to 18 kt through the evening.

Weekend Outlook...VFR through Sunday. Increasing mid-high clouds Saturday, then broken-overcast high clouds Sunday. Breezy W-NW wind gusts up to 15-20 kt each afternoon, otherwise variable surface winds less than 12 kt.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.