textproduct: Boise

KEY MESSAGES

- Hot, dry, and breezy conditions will continue today.

- Critical fire weather conditions, mainly over southeast OR and high terrain of southwest ID, through this evening.

- Isolated thunderstorms across southwest ID this afternoon and a slight chance overnight.

- Smoky conditions at times.

- Slightly cooler with near-normal temperatures Sunday through midweek.

SHORT TERM /Through Monday Night/

Southwest flow aloft continues over the area with hot, dry and smoky conditions today. Critical fire weather conditions remain through this evening, with low relative humidities and breezy conditions. Relative humidities are below 5% in some areas this afternoon. Enough lingering moisture over the Owyhees and northern NV will be enough to trigger isolated thunderstorms over far southwest ID this afternoon and the threat will continue overnight as a weak wave moves northeast. A slight chance of thunderstorms overnight over southwest ID mainly SE of a line from Boise to Stanley, ID. Drier air moves into the area on Sunday with slightly cooler temperatures and continued low humidities. Winds aloft will be weaker Sunday and Monday so afternoon breezes will be weaker.

LONG TERM /Tuesday through Saturday/

An upper level four corners high, and a trough over British Columbia, will keep our area under southwesterly flow aloft. Monsoonal moisture will remain south and east of our area in this pattern, leading to a hot, dry, and breezy long-term period. Near (leaning above) normal temperatures will warm to around 5 degrees above normal come Thursday, as the upper-level high shifts west over the Great basin.

AVIATION /18Z Saturday through Sunday/

Issued 1210 PM MDT SAT JUL 25 2026 VFR. Isolated to scattered thunderstorms this afternoon, mainly south and east of KTWF/KJER. Storms capable of outflows up to 40 kt and brief heavy rain. Wildfire smoke leading to reduced visibilities, most notable overnight and early Sun/AM with MVFR conditions possible in E-Oregon. High density altitude this afternoon due to heat. Surface winds: NW-SW 5-15 kt with Sw gusts to 25-30 kt this afternoon. Winds aloft at 10kft MSL: SW 15-35 kt.

KBOI...VFR with hazy conditions due to wildfire smoke. High Density altitude this afternoon due to heat. Surface winds: NW 8-12 kt this afternoon, then variable or W-SW overnight.

Sunday Outlook...Wildfire smoke with areas of MVFR visibility and mtn obscuration during night/morning hours, slightly improving for the afternoon. A 10% chance of showers/thunderstorms Sunday AM, mainly south of KEUL-KSNT line in SW Idaho. High density altitude during PM due to heat. Surface winds: SW-NW 5-15 kt with gusts to 25 kt Sunday. Highest gusts will favor E Oregon and Owyhees.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Red Flag Warning until 9 PM MDT this evening for IDZ401-402- 423. Heat Advisory until 9 PM MDT this evening for IDZ012-014-016- 033. OR...Red Flag Warning until 9 PM MDT /8 PM PDT/ this evening for ORZ670>675. Heat Advisory until 9 PM MDT /8 PM PDT/ this evening for ORZ063-064. Air Quality Alert until 11 AM PDT Monday for ORZ062.