Lewistown, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

296
FXUS65 KTFX 062331
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
531 PM MDT Fri Jun 6 2025

Aviation Section Updated.

.KEY MESSAGES...


 - Breezy to locally windy conditions, especially along the Rocky
   Mountain Front, will diminish tonight with a turn to north or
   northwest winds and cooler temperatures expected Saturday.

 - Mainly dry conditions are expected through at least Monday with temperatures
   rebounding to as warm as the 80s to around 90 for Monday and
   Tuesday.

 - A transition back to seasonal temperatures with opportunities for
   precipitation is expected by mid to late next week.

&&

.DISCUSSION...
/Issued 217 PM MDT Fri Jun 6 2025/

 - Meteorological Overview:

A series of shortwaves currently moving through northern BC and AB
will dive southeast and carve out a trough across the Canadian
Prairie Provinces this weekend downstream of a building upper level
ridge along the west coast. Breezy west to southwest winds,
primarily across north-central MT with higher gusts along the Rocky
Mountain Front, will diminish some tonight but enough wind persists
to keep minimum temps relatively mild tonight (in the 50s) across
the plains. A cold front associated with the energy moving
through AB drops south through the area Saturday morning, shifting
winds to the north and northwest with a cooler airmass and
surface high pressure sliding south along the Rockies and cooling
temperatures back to near or even slightly below seasonal
averages. While most locations will see a brief period of gusty
north or northwest winds with frontal passage, eastern portions of
north-central MT will see sustained windier conditions through
Saturday afternoon and into the evening in closer proximity to
larger scale troughing moving across SK. Moisture is limited with
this system but northwesterly upslope flow into the central MT
mountains will generate widespread mid level clouds across north-
central MT with a few sprinkles or light showers possible, mainly
near the central MT mountains.

The Canadian trough moves on toward the Great Lakes Sunday allowing
upper level ridging to shift inland Sunday and across the Northern
Rockies and MT Monday. Temperatures rebound back to near or slightly
above seasonal averages Sunday, climbing to well above average
daytime maximum temperatures in the 80s to around 90 at many lower
elevation locations for Monday and Tuesday.

The upper level ridge begins to flatten by late Tuesday with general
agreement among models on a series of fairly weak shortwaves and
associated moisture moving east/northeast across the region in the
more zonal flow that follows through much of next week. Confidence
in the timing and location of these disturbances is still low but
the risk for showers and thunderstorms looks to increase beginning
late Tuesday through much of next week.

 - Forecast Confidence & Scenarios:

There is some potential for the transport of Canadian wildfire smoke
into the area this weekend as steering flow behind the trough moving
across the prairies would put at least central and eastern portions
of the state downstream of fires currently burning in northeast BC and
northwest AB. These areas are under cloud-cover and may be receiving
some precipitation today so there is uncertainty in how much fire
activity and smoke is being produced. Smoke modeling does show
some lower concentration smoke moving into eastern portions of
north-central MT later Saturday into Sunday. Hoenisch

&&

.AVIATION...
07/00Z TAF Period

VFR conditions are mostly expected for this TAF period, but
variable cloudiness and an isolated shower or sprinkle can be
expected tonight in the wake of a passing shortwave trough. West
to northwesterly surface winds will generally remain gusty during
the overnight hours, especially along the Rocky Mountain Front and
the plains west of I15 where gusts will exceed 30 kts at times. A
cold front will cross the Canadian border around 07/10Z and
continue moving through the plains Saturday morning. Its southward
momentum will slow considerably while moving through the
southwest later in the day. Isolated shower activity and 10 to 20
kt northwesterly winds develop behind the front, mostly over
Central and North- central Montana. - RCG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  53  71  49  77 /  10  20   0   0
CTB  51  68  44  77 /  10  20   0   0
HLN  54  78  50  80 /  10  10   0   0
BZN  45  78  46  76 /  10  10  10   0
WYS  37  72  39  73 /  10  10  10   0
DLN  44  79  47  77 /  10   0   0   0
HVR  54  71  44  76 /  10  10   0   0
LWT  50  67  45  69 /   0  20  10   0

&&

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

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