318
FXUS65 KTFX 110501
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1101 PM MDT Thu Jul 10 2025

Aviation Section Updated.

.KEY MESSAGES...

- Isolated to scattered showers and thunderstorms and breezy to
  gusty winds across North Central MT this afternoon.

- A drier and warmer weekend.

- Precipitation and cooler than average temperatures for the
  beginning of next week.

&&

.UPDATE...
/Issued 830 PM MDT Thu Jul 10 2025/

A cooler airmass continues to surge south across the region this
evening behind a cold front that has shifted winds to the north
across most of the area. North winds gusting as high as 35-40 mph
in the 1-2 hr period following the initial frontal passage will
spread south through the remainder of southwest MT over the next
several hours while winds gradually diminish from north to south
in the overnight period. Showers that developed behind the front
across north-central MT will persist for a few more hours from
Great Falls to Lewistown before dissipating. Satellite imagery
shows the back edge of this area of clouds and showers already
nearing the AB/MT border and this clearing will gradually spread
south through the overnight period. Hoenisch

&&

.DISCUSSION...
/Issued 830 PM MDT Thu Jul 10 2025/

 - Meteorological Overview:

A cold front passage today will bring isolated to scattered showers
and thunderstorms south from Canada and into North-Central MT.
Weak CAPE and DCAPE will keep winds sub severe with showers and
thunderstorms. Gustier 700mb winds and the cold front passage
will help keep breezy to gusty winds across the North-Central MT
Plains this afternoon. Behind this, high pressure and northwest
flow aloft kicks in for the weekend. Subsidence at the surface
will keep the region mostly dry Friday through Sunday. Across the
Hi-line Sunday, an increase in PWATs ahead of the next incoming
system will bring a slight chance for isolated showers and
thunderstorms Sunday afternoon. Temperatures also increase back
to above average this weekend.

The drier and warmer weather won`t last too long. Ensembles are
starting to hint at a weather system passing through Monday and
Tuesday, bringing wetter and cooler conditions to start out the
week.

 - Forecast Confidence & Scenarios:

PWATs reaching close to 1" towards the Canadian border will allow
for a few isolated, brief moderate to heavy shower this afternoon
along the Hi-line, but widespread wetting rain is not anticipated
today.

Recent ensembles runs are starting hint at a more wetter, cooler
system moving in beginning of next week. There are some
inconsistencies still on how cool it gets, but confidence is
increasing for below average temperatures. A few models show
maximum temperatures Tuesday fall 10-15 degrees below normal.
There`s a 20-50% chance for 0.25" of rain Monday and Tuesday and a
20-40% chance for 0.5". -Wilson

&&

.AVIATION...
11/06Z TAF Period

VFR conditions will prevail at all terminals through the TAF
period.

Scattered showers behind the cold front will continue to make
their way to the south bringing some low-VFR ceilings and periods
of mountain obscuration through the first 6 hours of the period.
Winds will diminish heading into the overnight hours and remain
light through the remainder of the period. Low to mid-level clouds
will give way to mostly clear skies across all terminals by
11/16Z.  -thor


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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  80  53  91 /  40   0   0   0
CTB  42  78  52  85 /  40   0   0   0
HLN  51  83  54  90 /  20   0   0   0
BZN  49  81  50  90 /  10   0   0   0
WYS  41  74  38  81 /  10  10   0   0
DLN  46  78  48  87 /   0   0   0   0
HVR  46  81  53  90 /  40   0   0   0
LWT  43  73  50  85 /  30   0   0   0

&&

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

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