FXUS65 KBOI 051834

AFDBOI



Area Forecast Discussion

National Weather Service Boise ID

1234 PM MDT Wed Aug 5 2026



.UPDATE...Updated aviation discussion.



&&



.KEY MESSAGES...

- Warming trend will bring temperatures near to above 100

  degrees by Thursday through the weekend.



- Breezy winds Friday through the weekend with very low 

  precipitation chances returning along the ID/NV border.



- Smoky conditions continue through the week.



&&



.SHORT TERM /Through Friday Night/...

Issued 353 AM MDT WED AUG 5 2026

Continued amplification of the Desert Southwest upper-level 

ridge is expected over the area through the short term. This 

will continue the trend of hotter and drier weather, with each 

consecutive day warming a few degrees from the previous day. By 

Friday afternoon, temperatures 100-105 are forecast to be 

widespread in elevations below 5000 ft MSL. Overnight minimum 

temperatures will also be a concern for these lower elevations, 

with reduced relief from temperatures only cooling to the mid 

60s to even localized 70 degrees overnight. Localized dense 

smoke conditions could stand to temper these by a few degrees, 

but widespread heat impacts are expected Thursday and especially

Friday. Speaking of smoke, continued effects are expected over 

the next few days. Air quality alerts are ongoing for Southeast 

Oregon and Southwest Idaho and are in effect until at least 

Thursday. Some mild improvement to smoke is expected each day as

mixing occurs in the afternoon from diurnal heating and 

afternoon breeziness.



&&



.LONG TERM /Saturday through Wednesday/...

Issued 353 AM MDT WED AUG 5 2026

Stronger westerly flow aloft will move into the area as upper-

level troughing builds offshore and the Desert Southwest ridge

flattens and weakens. While hot temperatures will continue,

increased winds and the low possibility of precipitation return

to the forecast. Current long range models keep the 

precipitation primarily in far southern ID & along the ID/NV 

border, which would manifest itself through afternoon 

thunderstorms. Precipitation chances generally increase day 

over day as monsoonal moisture is transported north. For now, 

it looks as though the rest of the Great Basin and Desert 

Southwest will receive the precipitation, but our region is on 

the cusp. Temperatures will be 5-10 degrees above normal with 

lower valleys near 100 degrees Saturday, decreasing to near 

normal / about 5 degrees above normal Sunday onward. Breezy 

winds and hot temperatures will create fire weather concerns. 

Smoky conditions will continue from area wildfires which may 

keep temperatures slightly cooler than forecast.



&&



.AVIATION /18Z Wednesday through Thursday/...

Issued 1231 PM MDT WED AUG 5 2026

Reduced visibility due to wildfire smoke, with areas of MVFR-IFR and 

mountain obscuration, otherwise low VFR. High density altitude 

during afternoon due to heat. Surface winds: variable 5-10 kt. 

Winds aloft at 10kft MSL: W-NW 5-15 kt shifting to SW 5-15kt by 

18z/Thu.



KBOI...low VFR due to wildfire smoke. Surface winds: NW 5-10kt 

becoming SE 5-10kt after sunset.



&&



.BOI WATCHES/WARNINGS/ADVISORIES...

ID...Air Quality Alert until 2 PM MDT Friday for IDZ011>015-028-029-

     033.

     Heat Advisory from 2 PM Thursday to 9 PM MDT Saturday for 

     IDZ012-014>016-029-030-033.

     Air Quality Alert until 1 PM MDT Thursday for IDZ016-030.

OR...Heat Advisory from 2 PM MDT /1 PM PDT/ Thursday to 9 PM MDT /8 

     PM PDT/ Saturday for ORZ061>064.

     Air Quality Alert until 1 PM MDT /noon PDT/ Thursday for 

     ORZ061>064.

&&



$$



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AVIATION.....KA

SHORT TERM...CH

LONG TERM....CH