Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 251631
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1031 AM MDT Mon Mar 25 2024


.SYNOPSIS...

Unsettled northwesterly flow aloft will allow for primarily mountain
snow showers the next few days along the Continental Divide and
across Southwest and Central Montana. Temperatures trend warmer mid-
week before another series of weather systems bring precipitation to
the region late week into the weekend.

&&

.UPDATE...

The morning update has been published. Partial clearing is
underway over the N/NW portions of the CWA while clouds and
periodic light snow lingers farther southeast. Additional snow
showers may develop this afternoon through early evening, mostly
for areas over and adjacent to higher terrain. Another shortwave
and associated moisture moves in late tonight into Tuesday for
more light snow potential. This snow may be a bit more widespread
and may initiate more icy road conditions Tuesday morning despite
accumulations mostly remaining under 1 inch. Primary forecast
adjustment was to bring pops more in line with current trends
through Tuesday afternoon. - RCG


.AVIATION...
505 AM MDT Mon Mar 25 2024 (25/12Z TAF Period)

The primary concerns for this TAF period will include light
lingering snow and low clouds across the region this morning.
Ceilings rise/scatter out late this morning after lingering light
snow diminishes. Otherwise a few scattered snow showers look to
develop this afternoon along the Continental Divide and across
Southwest Montana terrain. Low ceilings look to redevelop across
portions of North-central Montana again tonight. Mountains will be
obscured this morning and again tonight. -AM

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

&&

.PREV DISCUSSION...
/ISSUED 254 AM MDT Mon Mar 25 2024/

Through Tuesday... The axis of a broad upper level trough is
shifting eastward across the central CONUS, allowing a northwesterly
flow to develop across the Northern Rockies. Mainly light snow
has lingered across the plains so far this morning. The thought is
that the snow will slowly subside as we head toward daybreak
across the plains, but continue a bit longer into Central and
Southwest Montana this morning. No changes are planned to the
going Winter Weather Advisory across northwest Beaverhead county
at this time, though most snow that will accumulate has already
done so. Although temperatures at the surface are below average
still, cold air being ushered in aloft will, in combination with
weak disturbances traversing the northwesterly flow, allow for
snow showers over the next couple days, primarily over and near
terrain along the Continental Divide and across Central and
Southwest Montana. Temperatures remain on the cooler side of
average for the next two days, but do trend closer to average
heading toward mid-week.

Wednesday into the weekend... Low amplitude ridging will build in
between large scale troughs well to the east and west for Wednesday.
Resultant flow aloft becomes zonal, allowing for a westerly to
southwesterly surface wind to develop. Wednesday looks to be dry for
most as a result, with temperatures trending to around average.
Something worth monitoring will be the potential for some blowing
snow along the Rocky Mountain Front late Tuesday night into
Wednesday, though with temperatures likely rising to and above
freezing in this area once winds develop, confidence in appreciable
blowable snow being around is low.

As quick as the ridging builds in Wednesday it will begin to be
displaced by broad upper level troughing heading into Thursday
through the early weekend. The first sign of this transition will be
a shortwave ejecting out of the broad trough across the Pacific NW
Thursday within a southwesterly flow aloft. This will re-introduce
chances for precipitation for most on Thursday into Thursday night
along and behind a Pacific cold front. Given temperatures behind this
front don`t look to fall too much, a mix of rain and snow looks most
likely at lower elevations, though details on specifics will need to
be worked out as confidence in timing of precipitation increases.
The chance for 0.25" liquid equivalent precipitation between
Thursday morning and Thursday night is only up to 20% at lower
elevations.

Looking toward Friday and next weekend, the pattern aloft becomes a
bit more complicated. The broad Pacific NW trough splits, with most
of its structure diving southward becoming a cutoff low off the
coast of California. Another portion of this trough will shift
eastward toward the Northern Rockies, eventually merging with
another trough diving southeastward out of northwestern Canada late
this weekend. The main takeaway is that an unsettled pattern looks
to remain Friday into the weekend, with temperatures falling to a
bit below average. At this point, no one day looks to be
particularly precipitation laden, but the chance for precipitation
will be around until upper level ridging looks to build in late
weekend or early next week. -AM

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  30  16  38  25 /  20  30  40  10
CTB  24  11  35  22 /  10  20  20   0
HLN  38  25  46  27 /  20  20  50  10
BZN  35  20  44  21 /  30  30  40  20
WYS  30  11  37  15 /  40  20  70  30
DLN  36  24  43  23 /  20  10  30   0
HVR  27   6  28  14 /  20  30  40   0
LWT  27  12  35  21 /  20  30  60  10

&&

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

$$

http://www.weather.gov/greatfalls


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