textproduct: Boise

KEY MESSAGES

- Dry and warm through Tuesday.

- Showers and thunderstorms and turning cooler Wednesday as a cold front moves inland.

SHORT TERM /Through Monday Night/

A ridge of high pressure will continue to build into the area over the next several days with a warming trend through Monday. Temperatures will warm an additional 10 degrees on Sunday and around 5 degrees on Monday. As the ridge strengthens, the surface winds shift to south-southeast aiding in the warming as well with breezy conditions during the afternoons through Monday.

LONG TERM /Tuesday through Saturday/

Tuesday will continue the trend of well-above average temperatures across the region, with the upper-level ridge over the Rockies and a cutoff low moving into the Western U.S. coast. With this sharp pressure gradient over the region, breezy southerly winds are forecast Tuesday afternoon. Beginning Tuesday evening into Wednesday, this cold-core Pacific low will bring cold air (behind a west-to-east cold front), widespread showers, and a slight chance of thunderstorms. Wednesday will become the wettest day, with the probability of precip climbing to 60-90% for the morning and afternoon. Snow levels will also lower to 5000-6500 ft MSL at that time as the low center moves overhead, allowing snow accumulation over the higher terrain. Maximum daily temperatures are forecast to drop as much as 20-30 degrees from Tuesday to Wednesday. Showers and below normal temperatures will persist into Thursday as the upper low becomes ingested into the parent Canadian trough to the north. This will solidify cool and unsettled northerly flow across the N Rockies as the low progresses east, with lingering mountain showers expected into Fri. Winds will be gusty Wednesday and breezy on Thursday behind the cold front and as the trough moves east.

The upper-level pattern becomes quite disorganized and variable across the long range models Friday onwards. What can be said at this time is that the clusters agree on below-normal upper-level heights, indicating an active pattern remaining.

AVIATION /18Z Saturday through Sunday/

Issued 1209 PM MDT SAT APR 18 2026

VFR under high clouds. Surface winds: E-SE 5-15 kt. Gusts to 20 kt in the lower Snake Plain into KBKE. Winds aloft at 10kft MSL:SW-S 5-15 kt.

KBOI...VFR. Surface winds: SE 7-14 kt. Gusts around 20 kt through the afternoon.

Sunday Outlook...Continued dry with periods of high cloud cover. Surface winds E-SE 10-20 kt with gusts to 25 kt, strongest in Snake Plain east of KBOI.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.