201
FXUS65 KBOI 162031
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
231 PM MDT Thu Jul 16 2026

.KEY MESSAGES...
- Afternoon and evening showers/thunderstorms today and Friday,
  mainly across southwest/central Idaho and far east Oregon.

- Some thunderstorms may become strong to severe today, capable
  of gusty outflow winds up to 60 mph, heavy rain, and hail.

- A marginal risk for excessive rainfall is forecast for Friday
  afternoon across central and south-central Idaho.

- Hot temperatures continue into early next week, with valley
  highs around 100 degrees; Hottest today.

&&

.SHORT TERM /Through Saturday Night/...
A push of monsoonal moisture this afternoon will make way for
showers and thunderstorms this afternoon this evening. The bulk
of this plume, and therefore thunder activity, will primarily be
across southwest and southcentral Idaho... although isolated
thunderstorms can`t be ruled out for eastern Oregon. Inverted-V
soundings and steep lapse rates underneath this mid-level
moisture will primarily support a wind threat. Storms will be
capable of wind gusts to 40-50 mph, up to 60 mph out of the
strongest storms the develop. While wind will be the main
hazard, brief heavy rain and small hail are also possible. Steep
terrain and recent burn scars will be the most susceptible to
heavy rain impacts, should a precipitation core pass over them.

Showers and thunderstorms will taper off after sunrise tonight,
before returning Friday afternoon/evening. Monsoonal moisture
will continue to increase across Idaho, with precipitable water
values increasing to near the 95th percentile of climatology
(model soundings indicate values of near an inch). This moisture
will continue to elevate heavy rain concerns, as scattered
showers and thunderstorms redevelop. Some guidance resolves
precipitation cores exceeding an inch in an hour. As is
typically the case, steep terrain and recently burned areas are
of most concern for flash flooding impacts. A Flash Flood Watch
has been issued for the Wapiti burn scar for Friday
afternoon/evening.

By Saturday, precipitation chances will begin tapering off as a
trough lifting towards British Columbia pushes the axis of
moisture east. Saturday afternoon, most of the activity will be
east of our area; isolated showers and thunderstorms will be
confined to higher terrain in the West Central Mountains and
southern Idaho. Heat will stick around throughout the short-term
period, with today being the hottest day as temperatures
increase up to 103 degrees in the Snake Plain this afternoon.
Temperatures will cool ever so slightly Friday and Saturday,
with lower elevation highs ranging from the mid-90s to around
100 degrees.



&&

.LONG TERM /Sunday through Thursday/...
The Four Corners / Central U.S. upper-level ridge is expected to
remain through the extended, with continued bouts of monsoonal
moisture coming into the area. Clusters and ensembles agree on upper-
level troughing off the Pacific NW coast with varying amplitude of
the ridging, thus placing the region in southerly/southwesterly flow
aloft. This will continue to funnel in higher moisture content air,
bringing precipitable water values back over 1.00" by Monday
(widespread PWAT values over 95% climatology). From Monday on, this
will fuel daily flooding threats from thunderstorms as they will be
heavy rain producers. Outflow winds will also remain a concern as
rain-induced cold pools will drive surface density gradients due to
surrounding heat. Hot and mostly dry conditions are anticipated
Sunday, with shower/thunderstorm chances limited to south-central
Idaho. Precipitation chances will increase Monday through Thursday
with continual pulses of monsoonal moisture.

&&

.AVIATION /18Z Thursday through Friday/...
Issued 1151 AM MDT THU JUL 16 2026

Mainly VFR. Isolated to scattered showers and thunderstorms
returning over southwest/central ID and far east OR this
afternoon. Stronger storms capable of outflow winds to 35-50 kt,
heavy rain with vis reductions, and small hail. Mtn obscuration
in storms. High density altitude due to heat in the afternoon.
Surface winds outside of storms: SW-SE 5-15 kt in the
afternoon, with gusts to 20-25 kt in SE Oregon. Winds aloft at
10kft MSL: southerly 5 to 15 kt.

KBOI...Mainly VFR. Isolated showers/thunderstorms in the area
this afternoon, with best chance at terminal between Thu/22Z
and Fri/02Z. Stronger storms capable of outflow winds to 30-45
kt, brief heavy rain with vis reductions, and small hail. High
density altitude due to heat in afternoon. Surface winds outside
of storms: SE-S 5-12 kt, with gusts up to 20 kt in the
afternoon.

Weekend Outlook...Mainly VFR. Showers/thunderstorms developing
Fri afternoon over portions of southwest/central Idaho, capable
of strong outflow winds, heavy rain with vis reductions, and
small hail. Mtns obscured in precip. Slight chance of
showers/thunderstorms over same areas Saturday afternoon, then
limited to south-central ID Sunday afternoon. High density
altitude due to heat. Surface winds outside of storms: SW-NW
5-15 kt, afternoon gusts 15-25 kt.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning until 9 PM MDT this evening for IDZ420-423-
     424-426.
     Heat Advisory until 9 PM MDT this evening for IDZ012-014-033.
     Flash Flood Watch from Friday afternoon through Friday evening
     for IDZ013.
OR...Heat Advisory until 9 PM MDT /8 PM PDT/ this evening for
     ORZ064.
&&

$$

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SHORT TERM...NF
LONG TERM....CH
AVIATION.....CH