Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 290229
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
829 PM MDT Thu Mar 28 2024

.SYNOPSIS...
Moisture falls across most of our region, today, with little to
no snow accumulation forecast for lower elevations. Mountain
passes will see minor snow accumulation with several inches of
snow likely across the mountains near Yellowstone National Park. A
cooler airmass settles across the area through the weekend with
some additional snow showers possible at times. A warmer and dry
weather pattern returns for early next week.

&&

.UPDATE...
Updated forecast is out. Just minor adjustments this evening.
Overnight lows adjusted towards current trends. Added at least
isolated rain/snow showers all areas through late this evening, as
showers are slow to diminish. However, the widespread impactful
snowfall in the West Yellowstone area has ended, thus the winter
weather advisory was cancelled earlier this evening. Also, the
airmass is becoming stable, so removed the mention of thunder.
Patchy fog is also likely tonight, especially over North Central
MT in areas where precipitation fell. Expect another round of
rain/snow showers on Friday. A few pockets of heavier snowfall are
possible Friday afternoon/evening, but I don`t think it will be
widespread enough for a winter weather advisory. Midnight shift
will take a closer look. Brusda

&&

.AVIATION...
645 PM MDT Thu Mar 28 2024 (29/00Z TAF Period)

A Pacific cold front has moved east out of North Central (KCTB
KHVR), Central (KGTF KLWT KHLN), and Southwest Montana, mostly
taking the more widespread rain/snow showers and MVFR/IFR conditions
with it. This leaves much of the area under scattered to broken VFR
clouds with only isolated rain/snow showers likely causing brief
periods of MVFR/IFR conditions through around 04Z. However, a
Canadian cold front will continue moving south of the border over
the plains through around 09Z, bringing mountain-obscuring MVFR/IFR
ceilings. After today`s showers, patchy fog will also be possible,
but the probability for dense fog is relatively low due to the
cloudiness. Ceilings should start to lift and break up after 16Z due
to daytime heating, but weak instability from KHLN south over
Southwest Montana may cause isolated to scattered rain/snow showers
to redevelop after 18Z. -Coulston

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

&&

.PREV DISCUSSION...
/ISSUED 645 PM MDT Thu Mar 28 2024/

Note: The forecast area for the National Weather Service Great
Falls Weather Forecast Office includes north-central, central and
southwest Montana.

Today...A Pacific upper level closed area of lower heights
resides off of the Washington State/Oregon west coast. Moisture
advects into our region, and widespread precipitation is forecast.
A Winter Weather Advisory is in place for the Gallatin and
Madison County Mountains and the Centennial Mountains where total
snowfall between 2 to 4 inches is forecast at lower elevations,
between 4 to 7 inches at mountain pass level, and higher amounts
at higher elevations. After sunset, moisture on surfaces freezes,
creating hazardous conditions. Additionally, mountain ridge winds
gust to as high as 35 mph. Visibility is reduced, at times, in
snow and blowing snow. All things considered, travel could be
difficult. Also, a few (<20% chance) thunderstorms may occur,
particularly across portions of central and southwest Montana,
this afternoon.

Tomorrow through Sunday...The afore mentioned upper level area of
lower heights dives south southeastward along the U.S. west coast,
while an upper level ridge builds over the Pacific Ocean, just
upstream, and the upper level pattern becomes highly amplified.
A cooling trend continues, and below normal high temperatures are
forecast through the weekend. An unsettled pattern prevails
through the weekend period, favoring periods of rain/snow by day,
and snow by night. Most moisture falls over the mountains;
however, periods of precipitation is forecast for our lower
elevations, as well.
- Fogleman

Next Week...A warmup is still on tap for early next week with good
multi-model ensemble support for ridging with daytime temperatures
likely to reach into the 60s for many areas by Tuesday. Beyond that
there are some differences in how quickly the ridge is broken down
by stronger troughing digging southward from the Gulf of AK with
cluster analysis showing around 40% of longer range model ensemble
members breaking down the ridge by Wed and 60% delaying the break
down until Thursday or Friday.
- Hoenisch

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  25  42  25  39 /  20  20  40  20
CTB  22  36  20  37 /  20  10  30  10
HLN  27  46  27  42 /  20  20  20  20
BZN  24  46  23  42 /  60  20  20  20
WYS  17  38  13  41 /  60  10  20  40
DLN  25  44  25  44 /  20  10  10  10
HVR  21  36  20  36 /  20   0  20  10
LWT  22  40  22  34 /  40  20  40  40

&&

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

&&

$$

http://www.weather.gov/greatfalls


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