Freeze Watch 1, NWS Missoula, MT

341 
WWUS75 KMSO 151944
NPWMSO

URGENT - WEATHER MESSAGE
National Weather Service Missoula MT
144 PM MDT Wed Sep 15 2021

MTZ001-161500-
/O.UPG.KMSO.FZ.A.0001.210916T0600Z-210916T1500Z/
/O.NEW.KMSO.FR.Y.0002.210916T0600Z-210916T1500Z/
Kootenai/Cabinet Region-
144 PM MDT Wed Sep 15 2021

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM MDT
THURSDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...Highway 2 Kalispell to Libby, Highway 37 Eureka to 
  Libby, Highway 56 Bull Lake Road, and Highway 93 Eureka to 
  Whitefish.

* WHEN...From midnight tonight to 9 AM MDT Thursday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Area Forecast Discussion
National Weather Service Missoula MT
259 AM MDT Tue Sep 14 2021

.DISCUSSION...Slightly warmer than normal temperatures are
expected this afternoon with weak high pressure over the region.

A trough and cold front moving south through British Columbia
will impact the Northern Rockies tonight and Wednesday. Available
moisture is coming in at around 200 percent of normal in northwest
Montana tonight, and convection-allowing models are starting to
show a higher likelihood for showers. As such, the coverage for
showers and rain amounts have been increased for Wednesday morning
in northwest Montana. Most of the rest of north-central Idaho and
western Montana are mainly only going to have gusty westerly
winds. West-central Montana and especially along the Divide will
have wind gusts of 35-45 mph.

Thursday is still expected to start out chilly with most valleys
dropping in the 30s, but high temperatures will rise to slightly
below normal.

The next trough, which is expected to bring a bigger change to
cooler and wetter, will move into the Pacific Northwest on Friday.
Cloud cover looks to increase with a breezy afternoon. Model
guidance are highlighting an atmospheric river of moisture,
associated with the trough, in southwesterly flow, which increases
confidence for widespread rain. North of Highway 12 in Idaho and
north of I-90 in Montana have the highest probability of a rain
event from Friday night through Saturday. There is a 40-50 percent
probability of 24-hour rain amounts from Clearwater County
through northwest Montana to be over 0.50 inches by Saturday
evening. Rain chances are high south of I-90 by late Sunday but
rain amounts are less certain.

&&

.AVIATION...Valley fog is showing up on current satellite loops
in northwest Montana. Most of the surface observations in the
valleys of northwest Montana are also coming in near saturated, so
fog is expected to increase in coverage through sunrise. Model
soundings show impacts from fog to decrease after 14/1600z.
Westerly winds will increase in the afternoon, otherwise, pleasant
flying conditions are expected in most of north-central Idaho and
western Montana.

&&

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