textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Light rain and mountain snow tonight and Wednesday. Isolated thunderstorms this evening.

- Strong cold front Wednesday afternoon followed by colder air and significant rain and snow Wednesday night through Thursday morning. Slight chance of thunderstorms Wednesday afternoon.

- Very windy in the Camas Prairie and Western Magic Valley Thursday afternoon, with gusts to 45 mph from the west.

SHORT TERM /Through Thursday Night/

Issued 219 PM MDT TUE MAR 31 2026 Light rain and snow tonight with snow level remaining above 6000 feet MSL. Enough instability for isolated thunderstorms until sunset. A strong north Pacific cold front will pass through our CWA Wednesday afternoon followed by colder air, rapidly lowering snow level, and significant rain and snow Wednesday night, decreasing Thursday. A slight chance of thunderstorms as the front passes. Snow level lowering to valley floors in eastern Oregon late Wednesday night, and almost to valley floors in Idaho Thursday. The supporting deep upper level low, near 52N/143W this afternoon, is forecast to pass directly through our CWA Thursday, with cold air aloft producing enough instability for graupel showers, and a slight chance of thunderstorms in all areas Thursday. Becoming very windy in south-central Idaho Thursday afternoon with westerly gusts increasing to 45 mph. A Wind Advisory has been posted for the Camas Prairie and western Magic Valley. Decreasing showers, mainly of snow, Thursday evening, and becoming quite cold by Friday morning, with lows in the teens and 20s with only the lower southern Idaho Valleys staying above 30 degrees.

LONG TERM /Friday through Tuesday/

Issued 219 PM MDT TUE MAR 31 2026 Warming and drying is the story in the long term. As the upper low in the short term heads eastward, northerly flow on Friday keeps things a few degrees below normal for this time of year. A building high pressure ridge over the area will warm temps 5-10 degrees each day through Monday, until temps reach 10 degrees above normal early next week. Highs in the valleys will be in the low 70s, mid 60s in highlands, and upper 50s in mountain valleys and ridges. After a warm Tuesday, an approaching low pressure system makes landfall on the coast, hinting at a cool and wet pattern after the long term. &&

AVIATION /06Z Wednesday through Thursday/

Issued 1145 PM MDT TUE MAR 31 2026 MVFR to IFR conditions in overnight fog and decreasing showers. Showers redevelop along a cold frontal passage tomorrow from west to east with a 15-30% chance of thunderstorms tomorrow afternoon across the region. Small hail/graupel are likely out of thunderstorms. Snow levels will drop from 6-7 kft MSL to 3-5 kft MSL by Thurs/06Z. Surface winds: light and variable overnight, then SW-NW 5-15 kt with gusts up to 35 kt possible near storms and near KBNO with the frontal passage late tomorrow evening. Winds aloft at 10kft MSL: SW 35-45 kt.

KBOI...VFR and overcast tonight with increasing rain showers tomorrow AM and a 30% chance of afternoon thunderstorms by Thursday. Thunderstorms could produce small hail/graupel and wind gusts up to 25 kt. Surface winds: variable less than 10 kt tonight, becoming SW- NW 8-12 kt.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Wind Advisory from noon to 6 PM MDT Thursday for IDZ016-028. OR...None.