340
FXUS65 KTFX 091128
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
428 AM MST Sun Nov 9 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Mild through the upcoming week, warmest Monday and Thursday.

 - Gusty winds return late tonight into Monday, gustiest on the
   plains west of I-15.

 - Next opportunity for more widespread precipitation does not come
   until late this week.

&&

.DISCUSSION...
/Issued 210 AM MST Sun Nov 9 2025/

 - Meteorological Overview:

High amplitude upper level ridging is building in across the region
early this morning. The only impact from weather through the day
today will be for some patchy fog and/or low clouds in the Havre
area this morning. Although the fog/low clouds to look to diminish
through the morning, it will result in another day of near average
temperatures for the Havre area while remaining areas across the
region take a step warmer.

A quick moving shortwave initially off the BC coast early this
evening flattens the ridge as it progresses eastward across southern
BC, AB, and eventually SK tonight and through the day Monday.
Guidance continues to hint at stronger cross barrier flow developing
from north to south along the Rocky Mountain Front late tonight into
Monday morning. BUFKIT soundings show support for ridgetop
stability/mountain wave activity. Strong winds/gusts along the Rocky
Mountain Front and across the adjacent plains will be a concern
after midnight near the Canadian border, spreading further south
through the remainder of the night and into the morning Monday.
While strong mid level flow continues into the day Monday,
confidence in any stronger winds being translated to the surface is
much lower during the day, outside of any additional mountain wave
activity, given ample mid to upper level cloud cover that is
forecast.

A lower amplitude ridge begins to build in across the western CONUS
Tuesday as the aforementioned trough contiues eastward across
Canada. Breezy winds look to linger on the plains into at least
early Tuesday. While temperatures look to remain on the mild side
Tuesday, they will be a bit cooler than Monday on the plains.

The axis of the upper level ridge slowly shifts eastward through the
middle of the week, shifting east of the region Thursday. Warm air
advection looks to be strongest Thursday ahead of an approaching
Pacific trough, which will result in another very mild day.

Details become more uncertain at this range, but there is increased
confidence for a cold front moving across the region Thursday night
or Friday, which will introduce the next more widespread opportunity
for precipitation. That said, the probability for precipitation on
the plains remains low at this time. -AM


 - Forecast Confidence & Scenarios:

Rocky Mountain Front and adjacent plains winds late tonight into
Monday:

The timeframe with the greatest confidence in strong winds/gusts
being translated to the surface is primarily focused on the ~3AM-
Noon timeframe Monday and is associated with mountain wave activity.
The area of greatest concern is in the typically windy areas along
the Rocky Mountain Front, adjacent plains, and out to the Cut Bank
area. While probabilistic guidance isn`t overly supportive of these
stronger winds/gusts (Only localized areas of 50% or greater
probability for High Wind criteria), the combination of strong cross
barrier flow and at least marginal ridgetop stability give me enough
confidence to go ahead with a High Wind Watch for the aforementioned
areas.

While gusty winds will certainly spread over the remaining plains
Monday morning and afternoon, it appears that the strongest mid-
level winds will struggle to mix down to the surface in any
widespread fashion. Hence no additional High Wind Watches are being
considered at this time further east over the plains.


Lingering gusty winds Monday night into Tuesday:

There is a small subset of guidance that continues a stronger cross
barrier flow into the evening and early overnight along the Rocky
Mountain Front Monday night. Should this higher end guidance verify,
it would result in another night of at least breezy winds along the
Rocky Mountain Front.

Heading into Tuesday, the probability for a 40 mph gust over the
plains largely falls in the 30-60% range, highest in typical wind
prone areas. -AM

&&

.AVIATION...
09/12Z TAF Period

Patchy fog in the Milk River valley may impact the KHVR terminal
this morning. Otherwise, a dry northwest flow aloft will maintain
VFR conditions with a gradual increase in high clouds. Increasing
westerly flow across the Rockies tonight will result in the
development of gusty surface winds at KCTB and KGTF by Monday
morning. Hoenisch

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  57  43  65  43 /   0   0   0   0
CTB  54  39  63  38 /   0   0   0   0
HLN  53  33  61  41 /   0   0   0   0
BZN  51  30  61  34 /   0   0   0   0
WYS  44  18  47  23 /   0   0   0   0
DLN  52  31  59  31 /   0   0   0   0
HVR  47  28  63  35 /   0   0   0   0
LWT  52  34  65  38 /   0   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from late tonight through Monday afternoon for
East Glacier Park Region-Eastern Glacier, Western Toole, and
Central Pondera-Northern High Plains-Southern High Plains-
Southern Rocky Mountain Front.

&&

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