864
FXUS65 KBOI 031550
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
950 AM MDT Thu Jul 3 2025

.DISCUSSION... Mostly clear across the majority of our area this
morning, making way for a much more active couple of days. Ahead
of an incoming trough that is currently of the West coast,
height falls will allow for instability to build across eastern
Oregon and across the higher terrain of southwest Idaho this
afternoon. The 12z BOI sounding shows weak elevated instability
already in place this morning. While large scale forcing is
subtle, orographic lift will allow for showers and thunderstorms
to develop around 2-4 pm MDT (1-3pm PDT) near the NV border.
Primary hazards include gusts up to 50mph, lightning, small
hail, and localized blowing dust. Multiple rounds of convection
are likely Thursday night/early Friday morning and then Friday
afternoon as the trough takes on a negative tilt and sends a
couple short-waves across our area. The morning convection may
help inhibit later convection Friday afternoon, this introduces
some uncertainty as to whether or not there will be enough
airmass recovery to support afternoon thunder. The current
forecast handles all of this well, no updates necessary.


&&

.AVIATION...Showers/thunderstorms will develop this afternoon near
the NV border and progress northeastward. Multiple rounds of
thunderstorms are possible through Friday morning, with gusts to
45 kt, small hail, and heavy rain. Blowing dust and
precipitation could cause local MVFR/IFR conditions. Surface
winds: W-NW 5-15 kt, some variability due to lingering weak
storm outflows. Winds aloft at 10kft MSL: WSW 5-15 kt.

KBOI...Mostly VFR. Showers/thunderstorm chances increase after
Fri/00Z, with erratic outflow winds 30-45 kt, lightning, reduced
visibility in rain and blowing dust. Surface winds outside of
storms: NW-W 5-15 kt.

Weekend Outlook...Widespread showers with embedded thunderstorms
across the area Friday morning become focused over high terrain in
SW and central Idaho Friday afternoon. Gusty winds, small hail, and
heavy rain are possible in storms. VFR Saturday and Sunday with
clearing skies. Surface winds NW 5-15 kt each morning and
afternoon.


&&

.PREV DISCUSSION...
SHORT TERM...Today through Saturday night...The short range
period will be active, with periods of showers and thunderstorms
today and Friday, and the chance for heavy rain late Thu night
into Friday. Early this morning, a few showers were moving
northeast across the area, but all thunderstorm activity had
ended as of 3:00 AM MDT. The remainder of the morning is
expected to be fairly quite, but thunderstorms will increase
near the NV this afternoon. Storms will move NE into the
evening, especially over eastern Oregon. This lines up well with
the Red Flag Warning in effect this afternoon and evening, and
no change has been made to that this morning. A significant
shortwave trough will move toward the area tonight, and pass
over in two parts. The first will move over the area early
Friday, while the second passes over Friday night. The first
wave has the potential to keep thunderstorms going all Thursday
night and into Friday morning. Moisture will increase ahead of
the wave, and there is good model agreement that storm coverage
will increase, and that some may contain heavy rain. Debris
flows, especially on/near burn scars, are possible in sloped
terrain, and a flood watch may be necessary if later guidance
continues to show this potential. For today`s storms, wind gusts
45 to 55 mph are possible. Tonight, wind gust potential will
fall slightly to 40-50 mph, still unusually high for nocturnal
convection. By Friday afternoon, peak gust potential rises back
up to 45-55 mph. By Saturday, with the final shortwave trough
moving off to the east, the remaining slight chance for showers
and thunderstorms will be over the West Central Mountain zone.
Saturday night should be dry.

Temperatures will drop to around 5 degrees above normal today,
then fall to a few degrees below normal Friday and Saturday.
Highs in lower elevations in the 80s will feel refreshing after
the heat we have experienced recently. Winds, apart from those
produced by showers and thunderstorms, should be generally out
of the NW during the afternoons averaging 5-15 mph.

LONG TERM...Sunday through Thursday...An upper-level trough
will stall out over the coast of California as a strong upper-
level ridge will build in over the Desert Southwest and Great
Basin. This will put SE Oregon and SW Idaho in a drying and
warming trend under southwesterly flow aloft. Models remain in
good agreement in the development of the ridge, thus forecast
confidence is high in a heat wave beginning Monday through
Thursday. Temperatures are still expected to be about 10 degrees
above normal, with lower elevations hovering just above 100
degrees for their afternoon highs. Exact high temperature values
may shift by a few degrees leading up to the event. However,
there is enough agreement in high temps that due to the multi-
day nature of the event, some sort of heat product will likely
be issued.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning from 2 PM this afternoon to 1 AM MDT Friday
     IDZ426.
OR...Red Flag Warning from 2 PM this afternoon to 8 PM PDT this
     evening ORZ670-672.

&&

$$

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DISCUSSION...NF
AVIATION.....JR
SHORT TERM...SP
LONG TERM....JM