Anaconda-Deer, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

351
FXUS65 KMSO 150928
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
328 AM MDT Thu May 15 2025

.DISCUSSION...

KEY MESSAGES:

-  Persistent showers across northwest Montana, generally north of
   Highway 200 today.

-  Friday morning valley fog, followed by afternoon showers.

-  Mild/dry start Saturday morning then increasing showers.

-  A very wet Sunday with cold/wet backcountry conditions.


The main focus for showers today will be over the Divide and
across northwest Montana generally north of Highway 200. If a few
sunny breaks occur, then there could be a few thunderstorms.
Partial clearing tonight will lead to possible fog by Friday
morning, though western Montana valleys could see a better chance
as north-central Idaho will start with rain.

A subtle yet significant change with the Sunday system is that
the trough is not digging as far south. This means more
precipitation amounts over the region as the better dynamics will
be closer. Right now, it appears that much of our region will
receive at least a tenth of an inch of rainfall(wetting rain).
This will be a soaking rain, with some areas across north-central
Idaho and portions of west-central Montana receiving 0.50 to 1"
plus amounts. The northern Clearwater Mountains have a 50 percent
chance for over an inch of precipitation. Snow levels will range
between 6,000 and 7,000 feet. So there could be periods of
moderate wet snow in the mountains Saturday night into Sunday.
Mountain passes that will be affected include Lost Trail, Williams
Creek Summit, Bannock, Lemhi, Nez Perce and Gilmore.

There could be patchy fog that develops by Monday morning across
the region, with residual clouds that hang on during the day.
Temperatures will begin to gradually moderate next week. It will
continue to be unsettled through Tuesday. Southwest flow with
milder temperatures from mid to late week could support spring
thunderstorms. Then the upper ridge is progged to build by next
weekend...NBM has 50 to 75 percent chance for highs getting back
into the 80s!


&&

.AVIATION...Showers will bring periodic reduction in ceilings and
visibility across the region today. The chance for showers lessens
across north-central Idaho and portions of southwest Montana this
afternoon. A few thunderstorms are possible across northwest
Montana between 15/1700 and 16/0000Z (11 am to 6 pm MDT). Patchy
valley fog is possible across western Montana Friday. Rain
develops in the Camas Prairie, Idaho by daybreak Friday.

&&

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

$$