Area Forecast Discussion
Issued by NWS Missoula, MT

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

FXUS65 KMSO 230959

Area Forecast Discussion
National Weather Service Missoula MT
359 AM MDT Wed Aug 23 2017

.DISCUSSION...The Northern Rockies will remain under a ridge of
high pressure for most of the day today. This will result in
fairly stable conditions, that will keep areas of smoke trapped in
the valleys degrading air quality. Missoula, Ravalli, and Granite
counties will be impacted the most, where an air quality alert
remains in place.

The high pressure will begin to breakdown and shift eastward
overnight tonight, allowing for a southwesterly flow to develop.
This pattern will aide in the development a few showers and
isolated thunderstorms around midnight tonight across north-
central Idaho and northwestern Montana along the ID/MT. Gusty
outflow winds and lightning will be the main threat, potentially
increasing fire weather concerns. Most areas will not see a
wetting rain (0.10" or more) out of this first wave.

Scattered showers and thunderstorms will shift eastward through
west-central and southwestern Montana as a quick moving cold
front moves across the region Thursday morning and afternoon.
Gusty outflow winds and lightning will once again be the highest
concern. Chances for wetting rains will increase for the area, but
will remain fairly spotty. Gusty southwesterly winds will occur
outside of the thunderstorms as well along and behind the front,
that will keep area wildfires active through the evening. The
region should remain breezy through the night into Friday morning,
with showers/thunderstorms lingering over southwestern Montana.

A ridge of high pressure will begin to build over the region
Saturday afternoon and will continue to strengthen throughout the
first half of next week. Hot and dry weather is expected to return
next week with highs in the upper 80s to low 90s expected for many
valleys. Stable conditions will keep smoke trapped in the valleys
and air quality will likely worsen during the first half of next


.AVIATION...Smoke from area wildfires will continue to reduce
visibility at area terminals especially at KMSO. Improvement in
visibility is expected later this afternoon/evening as the ridge
of high pressure moves off to our east. Isolated showers and
thunderstorms will be possible at area terminals late this
evening into tonight as a weak disturbance moves in.



$$ is the U.S. government's official web portal to all federal, state and local government web resources and services.