133
FXUS65 KTFX 110958
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
358 AM MDT Fri Sep 11 2026

.KEY MESSAGES...

- Scattered showers today, especially over North Central MT,
  otherwise much cooler.

- Another chance for lower elevation rain and mountain snow over
  the Rockies Sunday into Monday.

- Temperatures start to warm back up by late next week.

&&

.DISCUSSION...

 - Meteorological Overview:
A weak upper level disturbance is moving from west to east across
North Central MT this morning, producing a few thunderstorms along
the divide and scattered showers over the Plains of North Central
MT. That trend will continue through the morning hours, before the
precipitation starts to diminish this afternoon. Generally quiet
conditions expected tonight through Sunday morning, before the
next upper level low arrives by Sunday evening. The forecast
models have been decreasing precipitation amounts with this
system, and also pulling the precip a bit further north. This
system exits the region on Monday, with showers decreasing.

For Tuesday through Friday of next week, northwesterly flow aloft
develop by Wednesday, as a another upper level disturbance moves
southward through the area, producing some scattered showers. This
disturbance quickly exits the area by Thursday as an upper level
ridge tries to rebuild over the Northern Rockies by Friday. This
will result in warmer air moving back into the CWA by next Friday.

 - Forecast Confidence & Scenarios:
The main concern is how much precipitation falls Sun into Mon and
how low do the snow levels get. Overall the forecast models
generally have the max QPF of only around an inch over the
Northern Rockies. The probability of 1 inch of QPF in Glacier Park
is only 60 percent, with less than a 20 percent over much of the
northern Plains. Thus snow accumulations look mainly to be in the
advisory criteria, of 3 to 7 inches. Snow levels will be slow to
fall as well, but could fall down to about 6000 feet or so by
Monday morning. It is likely that a winter statement will be
needed for the Glacier Park area for this event.

Otherwise, just expect much cooler temperatures over the CWA for
the next week or so. That being said, temperatures will be quite a
bit cooler over North Central MT compared to Southwest MT, where
afternoon temperatures over Southwest MT will still be mostly in
the upper 60s and lower 70s yet. Brusda

&&

.AVIATION...
11/12Z TAF Period

Rain and isolated thunderstorms will affect much of North Central
MT this morning, with some IFR conditions expected at times.
Conditions improve this afternoon through this evening. There is
some fog potential by Saturday morning, just depending on how much
drying occurs this afternoon, but the probability is too low to
include at terminal sites at this time. Mountains/passes will be
obscured at least through mid day over North Central MT. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  58  43  58  40 /  90  10  40  20
CTB  52  39  50  36 /  80  30  40  30
HLN  65  45  64  44 /  70  10  10  30
BZN  71  41  71  40 /  10  20   0  20
WYS  70  30  71  38 /   0   0   0  30
DLN  73  38  73  41 /   0   0   0  20
HVR  64  39  59  37 /  60  10  30  10
LWT  58  40  59  37 /  90  30  20  30

&&

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

&&

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