042
FXUS65 KTFX 231850
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1250 PM MDT Mon Sep 23 2024

.SYNOPSIS...

Well above normal temperatures are expected through Wednesday as
upper level ridging moves over the Northern Rockies, with some
locations potentially reaching 90 degrees on Wednesday. Overall dry
conditions are expected through the work week, with the next
chance for more widespread light precipitation returning
Sunday night.

&&

.DISCUSSION...

Rest of today through Wednesday...Anomalously strong (1 to 2
standard deviations) H500 ridge over the Pacific Northwest will
build eastward and over the Northern Rockies on Tuesday, with the
ridge axis shifting over the Northern High Plains on Wednesday.
High temperatures beneath this ridge will warm some 10 to 15
degrees above normal on Tuesday and 20 degrees above normal on
Wednesday. Outside of the cold prone valleys of Southwest and
Central MonTana where overnight lows will consistently fall into
the 20s and 30s each night, most areas will remain in the mid-40s
to mid-50s with the warmest locations being where downsloping
southwest to west surface winds keep the boundary layer well mixed
throughout the overnight hours. Dry conditions are expected
across all of Southwest through North Central Montana over the
next 60hrs, with decreasing cloud cover through this evening
giving way to clear/mostly clear to sunny/mostly sunny skies. -
Moldan

Thursday through Friday... The Pacific trough will weaken as it
moves east across the area Thursday into Friday, but it will be
strong enough to break down the high pressure ridge and move a
weak cold front through the area. The breakdown of the ridge will
put the forecast area under a stronger westerly flow aloft, and
these winds will mix down to the surface at times in the wake of
the cold front; much of the area will have at least a 30 percent
probability of gusts exceeding 30 mph, but the Rocky Mountain
Front will have at least a 30 percent probability of 40+ mph
gusts. Although temperatures will cool down a bit closer to
seasonal averages, moisture will be somewhat lacking, so humidity
will remain on the low side, continuing fire weather concerns.
The downsloping winds will limit any potential for precipitation
to the mountains of the Rocky Mountain Front.

Saturday through next Monday... The NBM is showing that another
low pressure trough from the Pacific is forecast to approach and
move through the area this weekend into early next week,
potentially bringing more unsettled weather and cooler than normal
temperatures. However, ensemble forecast model clusters continue
to be in disagreement between this scenario and one with a broad
high pressure ridge that would favor a less cool and unsettled
pattern. As a result, confidence is only moderate in the forecast
for this time period for now. -Coulston

&&

.AVIATION...
23/18Z TAF Period

The primary concern today will be for breezy winds at times out of
the west to northwest, primarily across the plains. A few instances
of mountain wave turbulence will be around, but are not forecast to
be widespread nor strong. Otherwise, VFR conditions prevail as cloud
bases lift and eventually diminish through the afternoon and early
evening. A brief instance of fog cannot be ruled out around daybreak
tomorrow in high-elevation Southwest Montana valleys. -AM

Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  51  83  53  88 /  10   0   0   0
CTB  52  82  47  85 /  10   0   0   0
HLN  47  82  50  88 /  10   0   0   0
BZN  41  79  45  86 /  10   0   0   0
WYS  30  72  32  74 /  10  10   0   0
DLN  39  78  46  82 /  10   0   0   0
HVR  51  81  49  89 /  10   0   0   0
LWT  44  79  52  85 /  10   0   0   0

&&

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

$$

http://www.weather.gov/greatfalls