Greer, Idaho Weather Forecast Discussion

524
FXUS65 KMSO 271824
AFDMSO
Area Forecast Discussion
National Weather Service Missoula MT
1224 PM MDT Sat Sep 27 2025
.DISCUSSION...
KEY MESSAGES:
-  Dry and warming conditions through the weekend with hazy skies
   due to wildfire smoke.
-  Pattern becoming cooler and wetter next week.
Very dry conditions continue with an upper-level ridge of high
pressure dominating the weather this weekend, resulting in
unseasonable and increasingly warm conditions, but much calmer
winds than the previous couple days. Valley temperatures will
reach the low 80s, with some lower river valleys in north-central
Idaho potentially reaching 90 by Sunday which is expected to be
the warmest day going forward.
A significant pattern change is on track for early next week as a
cool, moist Pacific trough displaces the ridge. On Monday,
moisture moving in aloft over a dry low-level airmass will create
conditions favorable for high-based thunderstorms with strong
outflow gust potential up to 50 mph primarily impacting north-
central Idaho and west-central Montana along and south of I-90.
By Tuesday, a deeper moisture profile will allow for more
widespread and efficient showers and thunderstorms. The primary
threat will then shift to locally heavy rainfall. The highest
confidence for substantial rainfall amounts is in upslope/windward
regions of north-central Idaho and into western Montana. Embedded
convection could cause locally intense rainfall rates that would
increase the risk of excessive runoff or flash flooding in steep
terrain and near recent burn scars. Current modeling suggests a
60% chance for 0.10 or more, and a 40% chance for 0.25 or more
of total rainfall accumulation by early Thursday morning in
valleys along US-93 and points east. There is also about a 10%
chance that no measurable rain will fall in this region during
this same period.
Considerable uncertainty remains in the forecast from Thursday
onward depending on the track and evolution of the upper-level
low. About 50% of global model ensemble members suggest that the
trough will weaken and lift northward leading to a drier and
breezy westerly flow returning for the end of the week. 20%
indicate a rapid return to ridging with warm, dry, and relatively
calm conditions returning. The remaining 30% of solutions portray
a series of shortwaves digging through the backside of the upper
level low which would keep conditions cool and unsettled all the
way through the following weekend.
&&
.AVIATION...High pressure will maintain generally clear skies, warm
daytime temperatures and light/terrain driven winds through the
weekend. Wildfire smoke will cause hazy skies and may locally
lower visibility at times, particularly across northwest Montana.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&
$$

NWS MSO Office Area Forecast Discussion