Lewistown, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

315
FXUS65 KTFX 150025
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
525 PM MST Wed Jan 14 2026

Aviation Section Updated.

.KEY MESSAGES...

 - A cold front will bring cooling temperatures through the day on
   Thursday to all locations, along with strong north winds to the
   plains of Central and North Central Montana.

 - A light rain/snow mix or snow is possible along the cold front
   on Thursday, most notably over the Island Ranges of Central
   Montana.

 - Temperatures moderate over the weekend after near normal highs
   on Friday.

&&

.DISCUSSION...
/Issued 222 PM MST Wed Jan 14 2026/

 - Meteorological Overview:

H500 ridge over the Northern Rockies today will shift westward and
back over the western seaboard by Thursday as a shortwave over the
Gulf of Alaska crests the ridge axis in Northern BC/Alberta and digs
southeast over the Northern High Plains through Thursday night. At
the surface a cold front will dive south and through North Central
Montana during the mid- to late morning hours and Central and
Southwest Montana during the afternoon hours on Thursday. This front
will bring cooler, near normal, temperatures to all locations for
the day on Friday, along with a period of strong and gusty north
winds to areas east of the I-15 corridor over the plains of Central
and North Central Montana. Additionally, a period of light rain/snow
mix or snow is possible along the southward advancing front, most
notably in the northerly upslope areas of Central Montana, but any
accumulations will be minor.

Temperatures will begin to moderate across Southwest through North
Central Montana through the weekend and early next week as upper
level ridging amplifies over the western seaboard and predominately
dry, northwest flow resides over the Northern Rockies. - Moldan

 - Forecast Confidence & Scenarios:

High Winds Thursday and Thursday night...

Climate anomaly indicators such as the NAEFS and ECMWF EFIs continue
to support to the potential for a climatologically unusual wind
event from the afternoon hours on Thursday through Friday morning in
wake of a southward advancing cold front, generally along and
northeast of a line from Judith Gap to the Sweet Grass Hills. H850
winds per NAEFS analysis are prog`d to reach between 35-45kts, which
combined with strong pressure rises and cold air advection in wake
of the aforementioned front could lead to the transport of these low
level winds to the surface. NBM probabilities for wind gusts in
excess of 48kts continue to run/have increased to in excess of a 70%
chance on the downwind/downsloping side of the Island Ranges (i.e.
Sweet Grass Hills, Bears Paw, Highwoods, Judith, and Snowy) of
Central and North Central Montana, along with extreme northeastern
portions of Northern Blaine County.

A High Wind Watch remains in effect for the Bears Paw Mountains and
Southern Blaine, Fergus County below 4500ft, and Northern Blaine
County from Thursday afternoon through late Thursday night given the
potential for strong north winds; with additional High Wind Watches
now in effect from Thursday afternoon through Thursday night for
Eastern Toole and Liberty Counties, Hill County, and Judith Basin
County and Judith Gap. Areas that will see the strongest north winds
through these timeframe will once again be in lee of the Island
Ranges, along with any terrain gaps where the the north winds will
be funneled through and subsequently enhanced. - Moldan

&&

.AVIATION...
15/00Z TAF Period

VFR conditions will prevail throughout the duration of the TAF
period, but mid- to upper level cloudiness will increase this
evening over the plains of Central and North Central Montana as a
weak disturbance moves southeast within northwest flow aloft.

&&

.CLIMATE...
The all time record high temperature for January for Great Falls
is 67 degrees. There is a 20 percent chance the high temperature
could go above the current forecast today of 62 and reach the all
time for January of 67 degrees.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  34  45  20  37 /  20  20  20   0
CTB  31  41  17  36 /  10   0   0   0
HLN  28  47  20  37 /   0   0  10   0
BZN  23  47  15  33 /   0   0   0   0
WYS   6  35   4  28 /   0   0   0   0
DLN  26  48  17  36 /   0   0   0   0
HVR  28  40  18  31 /  10  20   0   0
LWT  32  44  17  31 /  10  30  10   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from Thursday afternoon through late Thursday
night for Eastern Toole and Liberty-Hill County-Judith Basin
County and Judith Gap.

High Wind Watch from Thursday afternoon through late Thursday
night for Bears Paw Mountains and Southern Blaine-Fergus County
below 4500ft-Northern Blaine County.

&&

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