FXUS65 KBOI 191957
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
157 PM MDT Tue May 19 2026

.KEY MESSAGES...
- Mostly dry with temperatures warming through Friday. 

- Well above normal temperatures over Memorial Day Weekend. 
  Gusty winds and a few mountain showers possible on Memorial 
  Day.

- Turning cooler early next week with gusty winds and increasing
  chance of precipitation starting Tuesday. 

&&

.SHORT TERM /Through Thursday Night/...
Our region will remain positioned on the western edge of upper 
level troughing through Thursday. While the focus of organized 
precipitation will remain to our east, daytime instability will 
support widespread cumulus buildups over the mountains as seen 
this afternoon. There's a slight chance that showers could 
develop from the cumulus field across e-central Oregon and 
w-central Idaho mtns each afternoon. Localized gusty winds will
be possible from showers or more robust cumulus (with or w/o 
precipitation). Shower chances briefly increase to 15-25% in the
w-central Idaho mtns and s-central Idaho zones Wednesday night 
in response to a passing shortwave trough. Otherwise it's dry 
and temperatures are on the way up, leaving behind any 
frost/freeze concerns for the Snake Plain. By Thursday high 
temperatures will be several degrees above normal.

&&

.LONG TERM /Friday through Tuesday/...
A ridge of high pressure will build over the Western US by the
end of this week, bringing generally clear, warm and dry 
conditions to the region through Monday. Temperatures will be 
about 10-15 degrees above normal. The ridge will reach peak 
strength on Sunday, with high temperatures near 90F in the 
Treasure Valley. By Monday, models indicate that an upper level 
low moving into the Pacific Northwest will begin to increase 
chances for precipitation. The upper level trough will move 
inland on Tuesday, with about half of the models showing that 
the trough will evolve into a closed low over the Pacific NW by 
Tuesday or Wednesday. In either scenario, temperatures will cool
down 10-20 degrees by Tuesday increasing winds and chance of 
showers and thunderstorms (20-30% chance). 

&&

.AVIATION /18Z Tuesday through Wednesday/...
Issued 1214 PM MDT TUE MAY 19 2026
VFR. Scattered high based cumulus clouds will continue over the
area with some producing virga and gusty winds. Surface winds
generally W to NW at 5-15 kts, except in the vicinity of virga
where gusts to 35 kts are possible this afternoon. Winds light
and variable less than 10 kts tonight across the area. Winds
W-NW 10 to 15 kts on Wednesday.

KBOI...VFR. Surface winds NW 10 to 15 kts this afternoon. Winds
light and variable less than 5 kts tonight. Winds W-NW 10 to 15
kts on Wednesday.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.

OR...None.

&&

$$

www.weather.gov/Boise

Interact with us via social media:
www.facebook.com/NWSBoise
www.x.com/NWSBoise

SHORT TERM...DG
LONG TERM....JB
AVIATION...JB