169
FXUS65 KMSO 150840
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
240 AM MDT Tue Jul 15 2025

.DISCUSSION...

KEY MESSAGES:

- A potent storm with unusually cold, wet, and windy conditions
  will continue through today

- Mostly dry rest of the week, warming back up to near and above
  normal


Satellite imagery early this morning is depicting a well-formed
low pressure circulation over the northeast corner of Washington.
Radar returns indicate steady precipitation with several convective
cells over Lincoln, Flathead, and Lake counties. Some of these
cells are producing lightning. Gusty northeasterly winds from a
cold front associated with this low are showing up in observations
from across northwest and west-central Montana. Observers have
chimed in with reports of downed trees and power outages due to
the winds.

Today, the low pressure circulation will continue on an east-
southeast trajectory through the Idaho Panhandle and western
Montana. Model soundings and cross sections over northwest Montana
indicate a deep layer of moisture that will support 24-hour
rainfall amounts through this evening of one to two inches over
the Continental Divide in Glacier Park and surrounding mountain
ranges including the Whitefish, Swan, and Flathead. The lower
elevations of Flathead and Lincoln counties should expect one half
to one inch of rainfall. Snow levels will be around 8000 ft, so
you may see a dusting of snow on the high peaks in Glacier Park
when the clouds lift.

In addition to precipitation, the cold front moving from
northeast to southwest will continue to produce strong
northeasterly or easterly winds today. Gusts of 30 to 40 mph will
continue across northwest Montana into this afternoon, while
easterly winds will increase over west-central Montana this
morning. Winds will be more northerly over southwest Montana and
Lemhi County and will last through this evening. Temperatures
behind the cold front will be much cooler than yesterday. A 20-30
degree drop in daytime highs from yesterday to today will bring
some locations close to record cool high temperatures for this
date.

Upper level flow will begin to flatten on Wednesday. A warming and
drying trend will take place going into the weekend. Temperatures
will rebound to seasonable values. On Thursday, most ensemble
members are showing a fast-moving shortwave trough traversing the
northern border. This system will bring slight chances for
precipitation and increasing clouds to the Glacier Park region and
areas along the border such as Yaak and Eureka. Otherwise, expect
mostly dry conditions going into the weekend.



&&

.AVIATION... Radar returns early this morning are indicating
widespread convection over northwest Montana including KGPI. These
storms are capable of producing small hail, heavy rain causing
reductions in visibility, and frequent lightning. Expect
thunderstorms to continue through about 15/1300Z. Strong
northeasterly and easterly winds will continue throughout today.
KGPI and KMSO will see gusts of 20-30 kts. Winds will increase at
KBTM (northeasterly) and KSMN (northerly) around midday and
continue into this evening.



&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Wind Advisory until 2 PM MDT this afternoon for Flathead/Mission
     Valleys...Kootenai/Cabinet Region...West Glacier Region.

     Wind Advisory until 8 PM MDT this evening for
     Bitterroot/Sapphire Mountains...Butte/Blackfoot Region...
     Lower Clark Fork Region...Missoula/Bitterroot Valleys...
     Potomac/Seeley Lake Region.

ID...None.
&&

$$