644
FXUS65 KTFX 151740
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1040 AM MST Sat Nov 15 2025

Aviation Section Updated.

.KEY MESSAGES...

- Lingering rain and snow over central and north-central
  Montana diminishes and ends by this afternoon.

- Temperatures cool closer to average by the weekend while passing
  weather systems bring periods of mountain snow and lower
  elevation rain and snow showers.

&&

.UPDATE...
/Issued 845 AM MST Sat Nov 15 2025/

Current forecast mostly remains on track this morning. The main
precipitation shield looks to exit off to the east a little bit
earlier than forecasted. However, I left low end chances with
lingering moisture along the stationary front through the rest of
the morning (along the Continental Divide through the Little
Belts). -Wilson


&&

.DISCUSSION...
/Issued 845 AM MST Sat Nov 15 2025/

 - Meteorological Overview:

A stalled surface front over the plains will retreat back
northward today, allowing gusty west to southwesterly winds to
redevelop over central/North-central MT by the afternoon hours.
North of the front, an area of light rain and snow continues over
portions of the Hi- Line, mostly over Hill and Blaine counties.
Otherwise, most of the mountain snow will be over the higher
terrain of the Rocky Mountain Front and precipitation looks to
diminish and end for all areas by early afternoon.

There will be a brief period of transient ridging later today
through early Sunday before additional Pacific troughs slowly
meander through the Northern Rockies via weak and disorganized
flow aloft. This will bring periods of precipitation, most
widespread Monday through Wednesday. Temperatures aloft will be on
the warmer side with around -5C at 700 mb much of the time. This
should mostly confine light snow accumulations to the mountains.

Another trough moves into the western CONUS for the second half
of the week, but the reoccurring theme of the main low pressure
center shearing off to our south looks to reduce overall
confidence of widespread impactful precipitation and winter like
temperatures. - RCG

 - Forecast Confidence & Scenarios:

Light rain and snow over central/north-central MT today...

Light snow will impact the Hi-Line this morning with snowfall
amounts ranging from a dusting up to a couple of inches, highest
over northern Hill and Blaine counties. The snow will generally
accumulate over grassy surfaces, leaving mostly wet roadway
surfaces, with the exception of bridges and overpasses. The snow
will begin mixing with rain later this morning and the
precipitation will diminish and end by early afternoon.

Mostly mountain snow opportunities next week...

Decreasing middle and upper level flow aloft will result in
weaker and slower troughs moving through the Northern Rockies next
week. The lack of a defined steering current also reduces
confidence in forecast tracks. Overall, light snow accumulations
look to be mostly confined to mountain areas Monday through
Wednesday with lighter end shower activity for lower elevations.
This doesn`t mean that heavier snows can`t materialize in a
localized fashion depending on smaller scale dynamics.

Another opportunity for scattered areas of precipitation will
come at the end of the week, but uncertainty is high with at least
a portion of the responsible trough`s energy progged to shear off
to the southeast towards the Great Basin. Looking ahead,
ensembles have been dabbling with some better quality troughs with
colder air aloft for the Thanksgiving holiday week. These systems
are being monitored and more information will be given in the
near future as forecast confidence increases. - RCG

&&

.AVIATION...
15/18Z TAF Period

Low to mid-level clouds will linger through the first 6 hours of
the period across central and southwest Montana creating periods
of mountain obscuration through 16/00Z. Gusty winds will be
possible along the Rocky Mountain Front into portions of central
Montana with gusts up to 40kts possible for KGTF and KCTB.

Between 16/00Z and 16/10Z, winds will become lighter and cloud
decks are expected to lift with only few to scattered high clouds.

After 16/10Z, another round of low to mid-level clouds returns to
central and southwest Montana bringing back concerns for mountain
obscuration through the remainder of the period as well as a 30%
chance for rain/snow mix for portions of southwest Montana.

Dense fog will be a concern across the Hi-Line after 16/08Z with
the greatest impacts expected for KHVR. Right now there is high
confidence in visibility down to 1SM, however, hi-res model
guidance is pointing towards at least a 50% chance for
visibilities less than 1/4SM between 16/10Z and 16/16Z. For now,
the TAF will prevail IFR conditions but periods of LIFR/VLIFR
cannot be ruled out.  -thor

The KWYS TAF will not be issued until airport operations resume
next spring.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  59  34  54  38 /  20   0   0  10
CTB  54  28  49  32 /  20   0   0  10
HLN  58  34  54  37 /  20   0  10  20
BZN  60  31  55  35 /   0   0  10  10
WYS  47  26  47  30 /   0  10  60  60
DLN  56  32  55  35 /   0   0  10  20
HVR  54  27  52  32 /  80   0   0  10
LWT  58  32  57  36 /  40   0   0  10

&&

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

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