Shelby, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

392
FXUS65 KTFX 160159
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
759 PM MDT Sun Mar 15 2026

.KEY MESSAGES...

- It will remain dry through the day today.

- Periods of mostly light mountain rain/snow expected this week.

- There will be periods of strong winds Monday-Friday along the
  Rocky Mountain Front and North-Central MT plains.

- There will be warmup in temperatures starting Monday, reaching
  well above normal towards the end of the week.

&&

.UPDATE...

Satellite imagery this evening shows high clouds advancing into
the Northern Rockies as Pacific moisture moves over a building
upper level ridge centered offshore of the west coast. Expect
clouds to increase through the rest of tonight as the upper ridge
begins to shift inland, though any precipitation looks to be very
light and limited to areas near the continental divide.
Temperatures were falling quickly this evening across portions of
central MT where clouds were still thin and a widespread snowpack
is in place. Overnight minimum temperatures were nudged down some
for areas from Helena to Great Falls and Lewistown, however the
incoming cloud-cover should slow or end the cooling for many of
these areas after midnight. Otherwise, forecast is on track with
winds increasing along the immediate east slopes of the Rocky
Mountain Front overnight, potentially leading to the onset of some
drifting snow as well as some localized blowing snow there.
Hoenisch

&&

.DISCUSSION...
/Issued 558 PM MDT Sun Mar 15 2026/

 - Meteorological Overview:

High pressure over the region today will keep dry weather through
the rest of the day. Warm air advection with a small increase in
moisture moves in overnight Monday morning. This will develop
light snow for mainly the mountains. A warm front lifting to the
east will bring slight chances for light rain/snow to lower
elevations throughout the day Monday. The upper-level ridge
flattening out through the week will result in westerly flow
aloft bringing light, orographic rain/snow over the Continental
Divide. Temperatures are expected to warm up throughout the week,
with temperatures reaching the 60s-70s across lower elevation
towards the end of the week. Some melting of the recent snowpack
is expected with the warmer temperatures. However, overnight lows
in the mountain peaks look to stay in the 30s, which will help
the moderate melting overall. Also, any rain in the mountains if
any will be light, and doesn`t look to have an impact for
enhanced snow pack melting. Increased stream/river flows are
expected, but overall flooding risk is low at the moment.

Increasing westerly flow aloft will bring in a persistent mid level
jet through the week. These stronger winds mixing down to the
surface will bring periods of strong winds to the Rocky Mountain
Front and the North-Central MT plains throughout the week.


 - Forecast Confidence & Scenarios:

There is a little uncertainty in how soon the strong winds begin
to mix down to the surface Monday. Some models begin having
stronger 700mb winds in the morning, while some push it back more
towards the afternoon to evening. There seems to be better
agreement that the winds peak Tuesday morning with the better jet.
There is good enough confidence for these winds to mix down to
the surface at times to upgrade to a High Wind Warning. With the
uncertainty in how quickly the strong winds come in, and using the
latest HREF ensembles runs, I decided to bump up the start time
for the warning to earlier in the day Monday. This also will
decide how impactful blowing snow will be before temperatures warm
up Monday. Since guidance did hint at winds picking up sooner
Monday morning before the snow pack settles in the afternoon along
the Rocky Mountain Front, I decided to issue Winter Weather
Advisories to account to that. Farther east across the North-
Central MT plains, blowing snow will be more patchy/isolated so
they were left out of the Advisory for now.

Synoptics also support Wednesday being another windy day for the
Rocky Mountain Front. Another 700mb jet of 60-85kt winds and a
pressure gradient tightening brings the concern for another round
of strong winds. There is a 50-70% chance for 75 mph wind gusts
along the Rocky Mountain Front foothills and a 70% chance for 58
mph wind gusts farther east towards Cut Bank. -Wilson


&&

.AVIATION...
16/00Z TAF Period

Clouds will increase from SW to NE heading into the overnight
hours with increasing chances for precipitation across Southwest
Montana. At KBZN, KEKS, and KHLN, precipitation will start off as
snow and transition to a rain/snow mix by the mid-morning before
becoming all rain by the late morning/early afternoon. Periods of
MVFR/IFR conditions are possible after 16/06Z both as a result of
low ceilings and reduced visibility around heavier showers.
Mountain obscuration will remain a concern over the next 24-30
hours.

Surface winds along the Rocky Mountain Front will start to
increase after 16/12Z with high winds expected by the afternoon.
Gusty winds will spread out along the Hi-Line and portions of
Central Montana by the late afternoon/early evening with the
potential for high winds lasting through Tuesday afternoon. With
the initial increase in winds, there is a concern for BLSN at KCTB
and KGTF which may reduce visibility at times. In general, the
main threat for BLSN is expected to subside by 16/18Z but
depending on if the stronger winds take longer to reach KGTF,
there is a potential some BLSN may last into the mid-afternoon.
-thor

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  13  48  42  57 /  10  20  30  10
CTB  15  47  39  56 /  10  10  10  10
HLN  17  50  39  61 /  30  50  30  10
BZN  20  53  38  64 /  40  40  50  10
WYS  16  42  28  53 /  50  60  50   0
DLN  27  55  38  64 /  10  20  10   0
HVR   8  46  35  62 /   0  10  10   0
LWT   7  46  38  56 /  10  10  20  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 3 AM to noon MDT Monday for East
Glacier Park Region-Eastern Glacier, Western Toole, and Central
Pondera-Northern High Plains-Southern High Plains-Southern Rocky
Mountain Front.

High Wind Warning from 9 AM Monday to 6 PM MDT Tuesday for East
Glacier Park Region-Eastern Glacier, Western Toole, and Central
Pondera-Northern High Plains-Southern High Plains-Southern Rocky
Mountain Front.

High Wind Warning from 3 PM Monday to 6 PM MDT Tuesday for Bears
Paw Mountains and Southern Blaine-Eastern Toole and Liberty-
Fergus County below 4500ft-Hill County-Judith Basin County and
Judith Gap-Northern Blaine County-Snowy and Judith Mountains-
Western and Central Chouteau County.

&&

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