textproduct: Boise

KEY MESSAGES

- About ten degrees hotter Sunday, with lower elevations reaching 90 degrees for the first time this year.

- Record high temps on Tuesday with temperatures in the mid to upper 90s in the lower valleys.

- Cooler Wednesday with a chance of showers and thunderstorms.

SHORT TERM /Through Monday Night/

Breezy west-northwest winds this afternoon. Gusts to 30 mph in south-central Idaho and the Camas Prairie. Lighter winds in Idaho Sunday afternoon, but stronger in Harney County where gusts will reach 35 mph. A broad upper level ridge of high pressure centered along the coast today will amplify as it moves inland tonight and Sunday, resulting about ten degrees warming from today. High temps will be near 90 degrees in the Treasure Valley and southern Malheur County/OR. A weak but faster-moving embedded short wave will pass by to the north Monday with some middle and high clouds and 1-3 degrees cooling from Sunday.

LONG TERM /Tuesday through Saturday/

Daytime high temperatures will set records come Tuesday as high pressure aloft will allow temperatures to climb to 20-25 degrees above normal (in the 90s for lower elevations valleys). These temps may be among the hottest ever recorded so early in the season. While the air will be hot, water temperatures will still be cold, so it may be good to consider taking extra precautions if planning to recreate on the water.

Guidance is coming into better alignment on a trough making its way through the Intermountain West come Wednesday/Thursday. Ahead of this trough, a surge of moisture from this south will increase precipitable water values to the 80-90th percentile of climatology. This pattern evolution is favorable for thunderstorms across our area. As a result of this trough, precipitation and thunder chances will increase through Wednesday afternoon. The thunderstorm threat, compounded with breezy winds and low relative humidities, will result in an elevated fire weather risk where fuels are dry. Temperatures will begin to trend cooler beginning Wednesday, to more seasonable values by the end of the week. Precipitation chances will taper off at the end of the week, as upper-level ridging builds in briefly behind the trough. Come Saturday, another shortwave will begin to dig down the British Columbia coast toward our area.

AVIATION /18Z Saturday through Sunday/

Issued 1145 AM MDT SAT MAY 9 2026

VFR. Surface winds: W-NW 5-15 kt with gusts to 25 kt this afternoon near KTWF/KJER. Becoming variable 5-10 kt overnight. Winds aloft at 10 kft MSL: NW 5-20 kt.

KBOI...VFR. Surface winds: NW 8-12 kt with occasional gusts up to 18 kt this afternoon. Becoming SE 5-10 kt overnight.

Sunday Outlook...VFR. Surface winds SW-SE 5-15 kt with gusts to 25 kt in SE Oregon. A cold front Sunday night will bring NW gusts of 15-30 kt.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.