708
FXUS65 KTFX 121126
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
525 AM MDT Sat Sep 12 2026

Aviation Section Updated.

.KEY MESSAGES...

 -Mountain snow of 1-3" confined to the highest peaks of the Rocky
  Mountain Front with no expected pass impacts.

 -Additional rounds of showers through Sunday bringing rain and
  gusty winds with any storms that are able to develop Sunday
  evening.

 -Widespread gusty winds Sunday and Monday with High Wind Watch
  out for the Madison River Valley.

&&

.DISCUSSION...

A weak upper-level ridge briefly builds in through Today,
bringing cool and mostly dry conditions across the region. On
Sunday, the main closed upper-level we have been tracking over the
past several days continues to correct slower and further
northwest. As a result, QPF continues to drop and temperatures
have gradually moderated as the signal grows for strong
southwesterly winds Sunday and Monday area wide. Sunday remains
the primary day for precipitation and impacts, with shower
activity largely focused along the Hi-line and Rocky Mountain
Front closest to the low. Further south, an embedded shortwave
looking to primarily impact north-central Montana Sunday evening
into early Monday morning. Despite limited instability, decent
low-level lapse rates and mid-level forcing will support the
potential for a few weakly convective showers. Model soundings
show the classic inverted-v profiled, which combined with 40-50kt
700mb winds, will allow showers to transfer stronger winds down
to the surface. While the severe threat is low, localized strong
winds gusts remain a possibility with any of the stronger showers
or "storms".

On Monday, the low exits but low level winds remain elevated.
Mid-week, models are showing a healthy signal for another upper-
level low pressure to try and swing through the forecast area.
Uncertainty in regards to timing and strength is high but worth
keeping an eye on as it could bring additional chances of
precipitation or at least unsettled weather. Beyond mid-week, our
pattern remains locked in place with ridging anchored over the
South-Central Plains bringing multiple opportunities for weak
shortwaves to move through the regional flow. Additionally, models
are hinting at a stronger trough to attempted to push into the
Pacific Northwest before becoming a cut-off low introducing
additional uncertainty into the extended forecast.

 - Forecast Confidence & Scenarios:

Confidence is high that winter weather impacts will be negligible.
Snowfall of 1-3" remains strictly confined to high mountain peaks
along the RMF with no impacts to road surface or passes. If the
low pressure continues its trend of NW, QPF amounts will continue
to slip as we lose the forcing needed for more widespread
precipitation.

Confidence is moderate, but growing, in regards to elevated
surface winds Sunday into Monday. The new orientation and track of
the upper-low will increase surface winds across the area,
bringing widespread gusts over 30kt especially in the Plains and
Southwest flow aligned valleys in Southwest Montana. Madison River
Valley looks particularly favorable for winds gusting upwards of
55kts thus the placement of the High Wind Watch.

Confidence in the general forecast past mid-week remains low.
Questions in regards to upper-level pattern remain aplenty with a
wide array of potential from a cut-off low plaguing the region to
continued rounds of swift moving shortwaves. In the instance the
cut-off scenario takes place, generally expect prolonged period of
unsettled weather and cooler temperatures with increased cloud
cover. On the flip side, if the wave remains open than well see
much of the same with the current pattern. Quick moving
shortwaves bringing new rounds of weather to watch and
temperatures much more seasonal.

-JR

&&

.AVIATION...
12/12Z TAF Period.

Expect passing clouds across the CWA through the period. Ceilings
will be just above IFR conditions for most areas, mostly this
morning. Humidity is near 100 percent in many areas this morning,
but cloud cover is preventing fog development. That being said, some
patchy fog can`t be ruled out before 15z today. A few
sprinkles/light showers are possible today, but any rainfall impacts
should be minor. Mountains/passes will be obscured through at least
this afternoon. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  58  41  64  45 /  10   0  30  80
CTB  52  37  54  39 /  20   0  50  50
HLN  65  42  69  43 /   0   0  40  40
BZN  71  40  75  37 /   0   0   0  40
WYS  72  37  67  26 /   0  10   0  10
DLN  74  39  73  35 /   0   0   0   0
HVR  60  36  66  43 /  10   0  10  80
LWT  59  37  68  41 /  10  10   0  70

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from Sunday afternoon through Sunday evening for
Madison River Valley.

Fire Weather Watch for portions of Southwest MT on Sunday.

&&

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