118
FXUS65 KTFX 090933
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
Issued by National Weather Service Missoula MT
333 AM MDT Thu Oct 9 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Dry and mild conditions persist through Friday

 - A cold front moving across the region Saturday brings windy
   conditions, showers and a few thunderstorms followed by a
   period of rain and mountain snow Saturday night into early
   Sunday.

 - Much cooler temperatures and unsettled conditions are expected
   Sunday through the first half of next week.

&&

.DISCUSSION...
/Issued Issued by National Weather Service Missoula MT/

 - Meteorological Overview:

Upper level ridging extending from MT east across the north-
central US will maintain dry conditions through Friday with
unseasonably mild temperatures peaking Friday afternoon. A closed
upper level low currently centered offshore of the Pacific NW
will move inland this weekend and open to upper level trough with
a leading shortwave ejecting out of the trough across the region
Saturday night. Southerly flow increases ahead of this wave late
Friday through Saturday, bringing breezy to windy conditions
while also drawing unseasonably high atmospheric moisture
northward into the region ahead of a Pacific cold front that cross
the area late Saturday afternoon/evening.

Showers increase Saturday ahead of the cold front with a few
thunderstorms possible across primarily southwest into eastern
portions of central MT saturday afternoon, where some instability
will be present. An area of widespread precipitation develops
Saturday night following the frontal passage with snow levels
lowering enough to bring accumulation mountain snow to elevations
above 6000 ft by early Sunday morning.

Temperatures on Sunday will be much colder, in the 40s, form most
locations with the colder conditions likely to persist through
the first half of next week. Shortwave energy arriving from the
north/northwest into the upper trough causes it to deepen and
elongate southwestward next week with additional precipitation
chances as these features move through or eject out of the trough.
Snow levels look to lower to around 4000-5000ft and potentially
lower across northern areas with chances for low elevations
snowfall at times, through there is still considerable uncertainty
with the timing and location of any precipitation early next
week.

 - Forecast Confidence & Scenarios:


Models continue to depict an area of widespread moderate
precipitation developing Saturday night in response to
frontogenic forcing as the ejecting shortwave lifts through
region following the frontal passage and is supported by favorable
upper level jet dynamics. While most guidance shows snow levels
falling to around 6000 ft by Sunday morning where heavier
precipitation focused across eastern portions of SW and central
MT, there is potential for snow levels to fall more rapidly and
lower than currently indicated due to dome of the previously
mentioned dynamics. This will need to be monitored as an earlier
transition to snow could bring impactful winter conditions to
Bozeman pass in this scenario and even the Bozeman area it self
if snow levels would fall even quicker with more intense
precipitation. Hoenisch


&&

.AVIATION... 09/12Z TAF

A dry southwesterly flow aloft beneath upper level high pressure
will maintain VFR conditions at all terminals through the TAF
period with generally light surface winds. Hoenisch

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  64  38  76  48 /   0   0  10  10
CTB  60  33  69  42 /   0   0   0  10
HLN  68  40  77  48 /   0   0  10  20
BZN  72  39  76  46 /   0   0  10  10
WYS  67  33  65  40 /   0   0  40  40
DLN  72  39  72  44 /   0   0  10  30
HVR  67  38  74  44 /   0   0   0   0
LWT  66  41  76  49 /   0   0  10   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$
http://www.weather.gov/greatfalls