Inverness, Montana Weather Forecast Discussion

810
FXUS65 KTFX 290159
AFDTFX
Area Forecast Discussion
National Weather Service Great Falls MT
759 PM MDT Sun Sep 28 2025
.KEY MESSAGES...
- Isolated showers and thunderstorms south of I-90 tonight.
- Coverage of precipitation increases Monday and Tuesday, with
  the best chances along the Continental Divide.
- A cool down in temperatures for the second half of the week.
&&
.UPDATE...
A weak wave within an increasingly cyclonic southwesterly flow
aloft will maintain the opportunity for isolated showers for a few
more hours across Southwest Montana this evening. The going
forecast describes this well, hence no updates are needed this
evening. -AM
&&
.DISCUSSION...
/Issued 527 PM MDT Sun Sep 28 2025/
- Meteorological Overview:
The ridge in place will keep most of the region dry today. However,
increasing moisture and ascent aloft towards the MT/ID border will
produce some isolated showers and thunderstorms later this
evening. Monday, with more influence under the trough propagating
eastwards, a small embedded shortwave will increases coverage of
afternoon/evening showers and thunderstorms. Best chances for
precipitation will be along the Continental Divide, but there
will be some isolated showers/thunderstorms across the plains.
Tuesday, a cold front passing through will bring another round of
showers and thunderstorms along with an increase in winds in
Southwest MT.
The trough will continue to bring sporadic chances for
precipitation through the rest of the week. This trough will also
help bring in cooler air to bring back fall-like temperatures.
Cooler conditions look to trend still heading into next weekend.
Though there remains uncertainty in how much precipitation and how
cool it gets with the next weekend`s system.
- Forecast Confidence & Scenarios:
For thunderstorms Monday, low CAPE and shear will keep thunderstorms
on the weaker side overall. A mid/low level jet Monday will allow
for the isolated potential for a few stronger wind gusts with
showers/thunderstorms (40-50 mph). Precipitation with
showers/storms will stay light overall (~.10") but a few heavier
showers can create locally higher amounts.
For the system next weekend, there is uncertainty in the models of
the evolution of this trough and how much colder air it brings.
This will affect how much precipitation we get and snow levels.
Right now, there`s a 20-40% chance for 1" of snow at the higher
peaks Friday through Sunday.- Wilson
&&
.AVIATION...
29/00Z TAF Period.
Isolated showers and thunderstorms will affect portions of
southwest MT along and south of a line from Dillon to Ennis to Big
Sky through early this evening with local mountain obscuration
and gusty/erratic winds possible in the vicinity of cells.
Otherwise, VFR conditions prevail across the area under a south
to southwest flow aloft with mainly clear skies across
central/north-central MT tonight giving way to an increase in mid
to higher level clouds on Monday. Surface winds across the plains
will gradually veer to the east and southeast this evening with
southerly surface winds developing across much of the area on
Monday. Hoenisch
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF  46  86  55  79 /   0   0  10  20
CTB  41  81  49  72 /   0   0  10  20
HLN  49  83  53  76 /   0  10  30  40
BZN  47  80  49  74 /   0  20  10  30
WYS  36  68  39  60 /  20  30  20  70
DLN  45  77  48  69 /  20  10  40  40
HVR  46  85  53  79 /   0   0   0   0
LWT  49  83  53  79 /   0  10   0  20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls

NWS TFX Office Area Forecast Discussion