952
FXUS65 KTFX 201535
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
935 AM MDT Sat Jul 20 2024

.SYNOPSIS...

For today, there is an isolated chance of showers and
thunderstorms across higher terrain. Otherwise, dry conditions and
well above normal temperatures are expected to continue through
the middle of next week.

&&

.UPDATE...

While the forecast from last night remains on track for most of
the area, I did add in some precipitation chances along the Rocky
Mountain Front and across the Mountains of Southwest Montana due
to ongoing rain shower and thunderstorm activity. Ludwig

&&

.AVIATION...
20/12Z TAF Period

VFR conditions will prevail through the 2012/2112 TAF period;
however, slantwise visibility reductions due to smoke/haze from
wildfires burning across the Western US and Canada will be common
across Southwest through North Central Montana. Additionally,
afternoon through evening cumulus development will once again occur
over the higher terrain on Saturday, with an isolated shower or
thunderstorm also being possible over these same areas and
along/east of a KEKS, to KBZN, to KLWT, to KHVR line. With the
chance for any one shower or storm being below 20% across the
aforementioned terminals this afternoon I have withheld mention at
this time. - Moldan

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

&&

.PREV DISCUSSION...
/ISSUED 448 AM MDT Sat Jul 20 2024/

Today through Monday... The upper level ridge will remain over the
Northern Rockies through the weekend keeping temperatures well
above normal across the region. Winds will generally remain less
than 15 mph with an occasional gust up to 25 mph. While most
locations will remain dry through the weekend, isolated to
scattered showers and thunderstorms will be possible during the
afternoon and evening hours, most notably over higher terrain.
The primary threat from any shower or thunderstorm will be gusty
and erratic winds given the model inverted-v soundings.

Tuesday through next Saturday... Heading towards the middle of
next week, an upper level trough sets up off the coast of British
Columbia. As it tries to push to the east, it compresses the
ridge into a more positive tilt with the ridge axis stretching
into eastern Montana/southern Saskatchewan. This will lead to
significant warm air advection over Montana and a heatwave
lasting Tuesday through Thursday with widespread highs in the
upper 90s to low 100s across the lower elevations of the state. By
Thursday the trough starts to shove the ridge to the east with
ensemble clusters favoring the breakdown of the ridge towards the
end of next week. There is relatively good agreement amongst the
clusters that the trough will be positioned over southern British
Columbia by Thursday afternoon. From there, disagreement starts to
creep in as to how quickly the trough will be able to push east.
A couple of the clusters have the trough making it to southern
Alberta by Friday afternoon while other clusters have the trough
hanging back around southern BC. By Saturday, there is a general
agreement that the ridge will break down to some degree. What
will be interesting to watch is, compared to the model runs 24
hours ago, more clusters are agreeing on the trough digging
further south over the western CONUS. Depending how the trough
eventually sets up, at the very least, central Montana can expect
temporary relief by next weekend in which temperatures will be
brought back down closer to normal for this time of year. -thor

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  92  61  92  61 /   0   0   0   0
CTB  92  58  91  58 /   0   0   0   0
HLN  96  62  95  62 /   0   0   0   0
BZN  92  55  91  55 /  20   0   0   0
WYS  82  44  82  42 /  20   0  10   0
DLN  88  52  90  52 /  20   0   0   0
HVR  94  62  94  62 /  10   0   0   0
LWT  87  57  87  57 /  20  10   0   0

&&

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

$$

http://www.weather.gov/greatfalls