327
FXUS65 KBOI 272050
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
250 PM MDT Wed Aug 27 2025

.SHORT TERM...Tonight through Friday night...
A very moist airmass remains over the forecast area but drier
air is starting to make it`s way into eastern Oregon.
Thunderstorms are developing again with daytime heating and
increased atmospheric instability. Greatest potential for heavy
rain is across SW Idaho and will let the flash flood watch
continue for Idaho zones into this evening. Less storm coverage
and increased storm motion has diminished the flash flood threat
enough across eastern Oregon to cancel the watch for that area.

Showers and thunderstorms will diminish tonight as an elongated
shortwave trough axis extending from the central mountains west
along the OR/WA border lifts north. Still a chance (20-30%) of
showers and thunderstorms Thursday and Friday along the Nevada
border as an upper level ridge builds over the area. Otherwise,
dry conditions will prevail and temperatures will trend up to
around seasonal normals.

.LONG TERM...Saturday through Wednesday...A broad upper ridge over
the southwest United States will build north over Idaho Saturday
through Monday, bringing a slight warming trend over the weekend.
Lower valley daytime high temperatures will be in the upper 80s and
lower 90s throughout the extended forecast period. There is better
long-range guidance agreement on an upper low off the Pacific
Northwest coast taking an odd wobbling and quasi-stationary
behavior. The system is projected to stall off the coast of British
Columbia and Washington. For now, a chance(20-30%) of
afternoon/evening showers/thunderstorms remains in the forecast for
eastern fringes of the forecast area and along the Nevada border.
Otherwise dry conditions will prevail.

&&

.AVIATION...Moderate to heavy showers and isolated thunderstorms
late this afternoon and evening. Greatest coverage across SW Idaho.
Showers diminishing after sunset. Outflow gusts to 25-35 kt, heavy
rain, MVFR to local IFR conditions and mtn obscuration in heavy
rain. Visibility reductions near mtn wildfires. Localized MVFR/IFR
due to fog in valleys late tonight and early Thursday morning.
Surface winds: W-NW 5-15 kt becoming variable 10 kts of less after
sunset. Winds aloft at 10kft MSL: W-NW 15-25 Kts.

KBOI...Mainly VFR. Scattered showers and thunderstorms in the area
through sunset. Moderate to heavy rain with showers and storms with
gusty outflow winds 25-35 kt. Patchy fog late tonight and Thursday
morning with a 20-30% chance of impacting the terminal. Surface
winds: west-northwest 10 kt or less through sunset, then E-SE 5 kts
or less.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Flash Flood Watch until midnight MDT tonight
     IDZ011>016-028>030-033.
OR...None.

&&

$$

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SHORT TERM...TL
LONG TERM....TL
AVIATION.....TL