textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Normal temps today before another cooldown this weekend, conditions stay dry and breezy.

- Another round of precipitation Saturday night into Sunday with lower snow levels will bring snow to higher elevations.

- Patchy frost possible Sunday and Monday morning mainly east of Mountain Home.

SHORT TERM /Through Sunday Night/

Issued 246 AM MDT FRI MAY 15 2026 Dry zonal flow remains over the region today, keeping conditions stable with temperatures near seasonal normals. Highs will reach the upper 60s and low 70s in the lower valleys. Winds will stay light through tonight before the next system approaches from the northwest.

On Saturday, a cold upper level trough will dive south from the Gulf of Alaska, crossing into southeast Oregon and southwest Idaho by the afternoon. This system will usher in a significantly colder air mass. Breezy to windy conditions will develop Saturday afternoon, with west to northwest gusts between 30 and 40 mph common across the Snake River Plain. This could create periods of blowing dust. Precipitation will be limited but focused over the mountains. As the cold air filters in Saturday night, snow levels will drop quickly to around 5000 feet. Light snow accumulations are possible on mountain peaks and higher passes by Sunday morning.

The core of the cold pool will settle over the region on Sunday. Daytime highs will be 10 to 15 degrees below normal, struggling to exit the 50s in many valley locations. Breezy northwest winds will persist through the afternoon, making it feel even cooler. As skies clear and winds diminish Sunday night, excellent radiational cooling is expected. Frost will be a primary concern across the Snake River Plain with the best chance across Western Magic Valley early Sunday morning where temperatures are forecast to dip into the low to mid 30s.

LONG TERM /Monday through Friday/

Issued 246 AM MDT FRI MAY 15 2026 A gradual warming trend begins Monday as the trough departs to the east and a weak ridge builds in from the Pacific. After a chilly start with frost potential in the Magic Valley, temperatures will rebound under sunny skies.Temperatures should return to near normal levels by Wednesday. Dry conditions are expected to prevail through the remainder of the long term period under a more stable northwest flow.

AVIATION /18Z Friday through Saturday/

Issued 1149 AM MDT FRI MAY 15 2026 VFR and mostly clear today. Tonight and tomorrow morning, a cold frontal passage brings gusty winds and rain/snow showers to KBKE/KMYL. Snow levels 5-6 kft MSL. Surface winds: W-NW 5-15 kt with gusts up to 25 kt in open areas. The front brings 10-20 kt winds with gusts up to 30 kt tonight. Winds aloft at 10kft MSL: W 15-25 kt.

KBOI...VFR. Cold frontal passage just after midnight brings gusty NW winds and overcast skies. Surface winds: NW 8 to 12 kts with gusts to 20 kt this afternoon. Light and variable this evening before gusty NW winds arrive with the front.

Weekend Outlook: The cold front brings scattered rain/snow showers Sat/Sun, and continued gusty W-NW winds. Snow levels drop to 3.5-5 kft MSL Saturday night. Surface winds: W-NW 10-20 kt Sat, with gusts 25-35 kt. Stronger winds Sunday at NW 15-25 kt with gusts 30-40 kt over most areas.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.