Coram, Montana Weather Forecast Discussion

223
FXUS65 KMSO 061919
AFDMSO
Area Forecast Discussion
National Weather Service Missoula MT
119 PM MDT Sat Sep 6 2025
.DISCUSSION...
KEY MESSAGES:
- Thunderstorms today primarily for north-central Idaho,
  spreading into all of western Montana and north-central Idaho by
  Sunday
- Pattern change to cooler and wetter weather early next week
Mid-level moisture seen over southern Idaho will continue to work
northward undercutting a ridge of high pressure. This moisture
along with daytime heating will help to set off scattered showers
and a few thunderstorms. This activity will begin across southern
Idaho and Lemhi counties by mid afternoon reaching the I-90
corridor by late evening. While storms will likely have some
rainfall associated with them, the bigger threat will be lightning
and gusty outflow winds of 30-40 mph. A weak disturbance tonight
may keep a few showers and thunderstorms going into Sunday
morning. One caveat that could limit convective potential is the
abundant wildfire smoke across the region.
By Sunday, the ridge axis will shift eastward. Scattered showers and
thunderstorms are anticipated to initiate early/mid afternoon and
press northeastward impacting much of the area, most concentrated
from Flathead Lake southward. Greater instability and wind shear
will allow for the potential of a few strong storms with gusty
outflow winds and small hail the main concerns. A direct hit on a
burn scar could also lead to a localized debris flow. Smoke once
again may be a limiting factor to thunderstorm coverage and
intensity, although high resolution models show smoke gradually
diminishing in intensity throughout Sunday.
The cool and wetter pattern change still looks good beginning
Tuesday and continuing into next weekend as a trough settles over
the Pacific Northwest. Daytime temperatures return to seasonable
levels with low/mid 70s in western MT valleys, mid 70s to low 80s
for north-central ID valleys. Showers and a few thunderstorms will
be common each day with hints of a closed low sliding south of the
region late week. If this closed low does develop, then
widespread precipitation would be the outcome. Still a lot of
details to be ironed out but certainly a cooler and wetter pattern
ahead.
&&
.AVIATION...Mid-level moisture will gradually work south to north
across the Northern Rockies this afternoon through Sunday.
Scattered showers and a few thunderstorms are anticipated to
develop in southern Idaho and Lemhi counties by mid afternoon
lifting northward to about the I-90 corridor by late evening.
Watch for gusty outflow of 30-40 mph with convective activity. One
caveat that could limit convective potential is the abundant
wildfire smoke across the region, which will also continue to
reduce visibility to MVFR levels at times.
A weak shortwave may keep a few showers and thunderstorms going
into Sunday morning, once again mainly I-90 southward. Improved
instability and wind shear will open up the potential for a few
strong thunderstorms on Sunday afternoon, gusty outflow winds and
small hail will be the main concerns. A gradual reduction in
smoke impacts is shown in high resolution models Sunday afternoon
and evening.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&
$$

NWS MSO Office Area Forecast Discussion