textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Afternoon rain and snow showers over higher terrain through Wednesday.

- Gradual warming trend through the week.

- Thunderstorms possible this weekend.

SHORT TERM /Through Wednesday Night/

Issued 252 PM MDT MON APR 27 2026 A cool upper level trough remains over the area keeping unsettled conditions during the afternoons through the short term. Showers and a slight chance of thunderstorms over the mountains each afternoon through Wednesday. Temperatures will slowly moderate each day as a warming trend ensues.

LONG TERM /Thursday through Monday/

Issued 252 PM MDT MON APR 27 2026 A SW-NE oriented upper-level ridge axis will move over the area Thursday and Friday, bringing dry conditions, warm temperatures, and light wind speeds. Temperatures begin the period Thursday by increasing to around 5 degrees above normal. On Friday, temperatures rise further by another 3-5 degrees (totaling 10 degrees above normal), with similar temperatures expected over the weekend. This translates to lower valley highs in the upper 70s to lower 80s by the weekend. On Saturday, ensemble guidance indicates that an upper-level cut-off low will dive south along or near the Pacific coast. Model solutions vary wildly on location, track timing, and precipitation intensity. A more inland track over California and the Great Basin would bring showers and thunderstorms to our area, but models also indicate the potential for the low to remain offshore, which would keep our area warmer and drier. The net result in the uncertainty is a 10-30% chance of showers and a 5-10% chance of thunderstorms on Saturday. Probabilities increase to a 20-50% chance of showers and a 10-15% chance of thunderstorms Sunday and Monday, highest in the mountains and near the Nevada border. The forecast calls for above normal temperatures through Monday, but would trend cooler if the wetter pattern becomes more likely.

AVIATION /00Z Tuesday through Wednesday/

Issued 526 PM MDT MON APR 27 2026 Mainly VFR. Scattered showers and isolated thunderstorms will continue over eastern OR and west-central ID mountains this evening through sunset. Showers/storms capable of erratic gusts to 30 kt. Localized MVFR-IFR conditions and mountain obscuration in showers. Snow levels 4500-5500 ft MSL. Surface winds: W-NW 10-15 kt this evening, gusts 20-30 kt east of KBOI, becoming mostly variable under 10 kt tonight after sunset. Winds aloft at 10kft MSL: NW 10-20 kt.

KBOI...VFR. Surface winds: NW 10-15 kt with gusts 20-25 kt this evening, becoming variable under 7 kt tonight after sunset.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.