028
FXUS65 KMSO 240744
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
144 AM MDT Sun Aug 24 2025

.DISCUSSION...

- Locally degraded air quality from wildfire smoke and stable
  conditions, especially in north central Idaho and the Bitterroot
  Valley.

- Heat advisories remain in place for lower valleys of north
  central Idaho through mid-week.

- Increased chances for thunderstorms early to mid-week as
  monsoon moisture moves northwards from the Desert Southwest.

Wildfire smoke continues to degrade air quality across Idaho and
Clearwater Counties, where stable conditions and east winds
continue to funnel smoke into the area from the Clearwater
Mountains. Smoke has also began to impact air quality across the
Bitterroot Valley this morning. Elsewhere, vertically integrated
smoke has been present, but with less effects to air quality
degradation. Northwest Montana continues to see the least in the
way of wildfire smoke.

Heat advisories remain in effect across lower elevations of
north-central Idaho, including locations such as Orofino and
Riggins. High temperatures will range between 100 to 105 degrees
with little relief in the way of overnight cooling as low
temperatures fall into the upper-60s to low-70s. Elsewhere,
typical summertime temperatures are expected with valley highs in
the upper-80s to mid-90s across western Montana into early next
week.

A change in the overall pattern remains on track for early to
mid-week when monsoonal moisture meanders northward from the
southwest USA, bringing with it very high precipitable water
values (about 150% to 200% of normal). This means the amount of
available moisture in the atmosphere by Wednesday and Thursday
could cause very heavy downpours from thunderstorms that initiate
during this period. Forecast models suggest marginal instability,
limiting the risk for strong to severe organized convection. That
being said: this could turn into a flash flood concern very
quickly, especially given slow storm motions. Those with plans
near known flood prone areas or wildfire burn scars should remain
vigilant to the forecast by mid to late next week.

&&

.AVIATION...Light east-northeast winds will continue through this
morning, with winds turning out of the north-northwest after
24/2000Z this afternoon. As with yesterday, periodic gusts of
15-20kts will impact KMSO after 24/2200Z. Reductions in
visibility will continue to be prominent across north-central
Idaho, including KGIC due to wildfire smoke. East-northeast winds
will redevelop this evening into Monday morning.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...Heat Advisory until 9 PM PDT Wednesday for Lower Hells
     Canyon/Salmon River Region...Orofino/Grangeville Region.

&&

$$