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 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

000
FXUS65 KMSO 232108
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
308 PM MDT Wed Jul 23 2014

.DISCUSSION...

Complicated forecast picture next 24 hours for the Northern
Rockies with several threats on the horizon. The first threat is
convection late this afternoon and into the overnight hours. While
the atmosphere is currently favorable for thunderstorm
development, a mid-level cap has prevented anything thus far this
afternoon. It appears we will break that cap soon, and
thunderstorms are expected to generate across a good portion of
Southwest Montana. Meanwhile, the potent upper-level support and
associated cold front are still on tap to move into Western
Montana by this evening. This should strengthen storms, allowing
some to become strong while producing heavy rain, hail, and
strong winds. There is still some uncertainty with the timing of
the front, but the latest guidance suggests it will reach the
Bitterroot and Mission Valleys around 9pm-midnight as it moves
eastward. Behind the front, very gusty winds can be expected along
with strong showers and thunderstorms. Another concern worth
mentioning is flash flood potential over burn scars with cells
capable of heavy rain.

Windy conditions are expected to persist through Thursday, with
the strongest winds over Northwest Montana and especially Glacier
NP. This will combine with much cooler temperatures to create raw
conditions for the backcountry. Area boaters should expect choppy
conditions on Lakes in Western Montana, including Flathead Lake.
Cannot rule out a few snowflakes over the peaks of Glacier NP, but
nothing more than a dusting at the most. Showers and a few
thunderstorms should diminish from south to north during the day.

Friday will have a cool start for most locations. The current
forecast is near record lows, but still a bit warmer most
locations. The temperatures will be sensitive to winds, which may
linger a bit longer and keep the temperatures up. Dry weather is
on tap for Friday into the weekend with warming temperatures.

A ridge of high pressure will build over the Northern Rockies
later this week into next week. This ridge will cause temperatures
to steadily warm to above normal readings by Sunday, as many
locations will be back into the 90s. The models are hinting at
some moisture moving into the area by early next week, which might
cause some high-based thunderstorms during the afternoon/evening
hours.


&&

.AVIATION...Showers and thunderstorms are expected to initiate
around by around 23z in North Central Idaho and Western Montana
and intensify as they move to the northeast, affecting primarily
KBTM but possibly KMSO as well. Meanwhile, an upper-level
disturbance and surface cold front will be moving into N Central
ID and Western MT from Washington state. This should increase
thunderstorm chances at all terminals as the evening progresses
and into the overnight hours. Gusty winds will be the main threat,
with lightning strikes and hail also possible as well as brief
visibility reductions due to rain. After the front passes, winds
of 10-20 kts with gusts to 30 kts are possible at KMSO, KGPI, and
KBTM into Thursday, with breezy winds though not as strong at
KSMN.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$

Follow us on Facebook and Twitter!
https://www.facebook.com/US.NationalWeatherService.Missoula.gov
https://www.twitter.com/NWSMissoula









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