304
FXUS65 KBOI 212042
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
242 PM MDT Thu Aug 21 2025

.SHORT TERM...Tonight through Saturday night...Dry conditions
prevail through the early this weekend. Temperatures this
afternoon will reach the the low to mid 90s across lower
elevations. A ridge building in over the Four Corners region
will keep our area under dry southwesterly flow aloft. This
building ridge trough supports a warming trend through
Saturday, with lower elevations making it up to the mid-90s on
Friday. Come Saturday, flow aloft will back giving us more of a
southerly component. This supports even more warming with
temperatures reaching near triple digits on Saturday, making it
the warmest day. However, have help off on issuing any headlines
for the time being.

The backed flow aloft brings another consequence along with
it... some monsoonal moisture. While the bulk of this mid-level
moisture will arrive early next week, sufficient moisture (PWATS
around the 75th percentile) will creep into eastern Oregon and
to the Nevada border by Saturday afternoon. This supports a
slight chance (15-20%) of shower and thunderstorms in
southwestern Harney county and along and south of the Nevada
border. With model soundings showing a dry boundary layer, Storms
that develop Saturday afternoon will be high-based (LCLs close
to 500mb or 15000 feet above ground level), this means that
little rainfall will make it to the ground and outflow winds
will become the primary hazard. PWATs will continue to increase
through Saturday night as moisture continues to advect into the
region.


.LONG TERM...Sunday through Thursday...Upper ridge over the
interior western US will weaken starting Monday, but cooling will
begin Sunday as monsoon moisture brings clouds from the south.
A slight chance of thunderstorms will begin in southeast Oregon
early Sunday, then expand over most of our CWA Monday through
Thursday.  Gradual cooling through Thursday while the chance of
showers and thunderstorms slowly increases, especially in southern
areas. Initial thunderstorms will bring gusty winds but little
rain due to dryness in the lower atmosphere, but later storms
(Tuesday through Thursday) should be wetter as the lower levels
moisten.

&&

.AVIATION...VFR. Local visibility reduction in central ID due to
wildfire smoke. Surface winds: W-NW 5-15 kt. Gusts to 20 kt until
22/01Z. Winds aloft at 10kft MSL: NW 10-15 kt.

KBOI...VFR. Surface winds: NW 8-12 kt with gusts to 20 kt until
22/01Z, then variable less than 6 kt.

Weekend Outlook...VFR. Local visibility reductions in central ID due
to wildfire smoke. A 15-30 percent chance of showers and
thunderstorms near the Nevada border Sunday afternoon and evening.
Light and variable surface winds except gusty/erratic winds near
thunderstorms.


&&

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

&&

$$

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SHORT TERM...NF
LONG TERM....LC
AVIATION.....LC