Shelby, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

509
FXUS65 KTFX 300816
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
216 AM MDT Mon Jun 30 2025

.KEY MESSAGES...

- Dry conditions start out the week, with daily chances for
  showers and thunderstorms moving in region wide starting
  Wednesday.

- Hotter temperatures settle in for the week, with a cool down
  starting on Friday.


&&

.DISCUSSION...

 - Meteorological Overview:

The upper-level ridge building in and surface high pressure will
allow for mostly sunny skies tomorrow besides cumulus clouds
across higher terrain. Subsidence in place will keep the region
dry for Monday. The increased thickness in heights aloft will
allow for the heat to start building in for the week. Wednesday
looks to be the hottest day, as southwest flow aloft will advect
in warm and moister air. Starting on Tuesday, an upper closed low
will start to advect in monsoon moisture from the Southwest U.S.
This will begin daily chances for showers and thunderstorms
through the forecast period as a series of disturbances move
through. Tuesday`s precipitation chances will mainly be along and
south of the I-90 corridor, with the rest of the week having at
least a slight chances for precipitation through the week. Hot
temperatures and drier low levels of the atmosphere can allow for
a few strong wind gusts with thunderstorms. Though, chances for
severe storms remain isolated at this moment. Increased PWATs to
0.75-1" at times will bring brief heavy downpours with storms as
well.

Towards the end of the week, a cold frontal passage Thursday through
Friday morning will bring a relief to the hot temperatures Friday
and Saturday. Temperatures look to moderate out to near
seasonable for the beginning of next week.

 - Forecast Confidence & Scenarios:

Moisture advection is trending earlier, with it arriving by Tuesday.
There is an increasing signal for isolated showers and
thunderstorms Tuesday afternoon and evening mainly along and
south of the I-90 corridor as a result. Convection this week
doesn`t look robust overall with weaker shear and CAPE in place.
Hot temperatures Wednesday will create deep inverted V profile
soundings. This and DCAPE at 1,000+ will create an environment
for a few strong wind gusts with collapsing thunderstorms.
Thursday is looking similar across Southwest MT.

There is good confidence for 90 degree temperatures this week at
lower elevations. There`s a 80-100% chance for 90 degree
temperatures Tuesday afternoon for the lower elevated Southwest
valleys and along the Missouri and Milk River valleys. Wednesday,
there`s a 80-100% chance for 90 degrees in the same areas,
including most of the North-Central MT plains. The thermal belt
region in the Bear Paws is currently forecasted to have minimum
temperatures at the low to mid 60s Wednesday and Thursday, which
can elevate the heat impact. -Wilson

&&

.AVIATION...
30/06Z TAF Period

Ridging aloft will maintain widespread VFR conditions for the
duration of the TAF period. Winds will generally be light and
variable in the southwest and will develop an easterly component
over the plains on Monday. - RCG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  88  56  91  58 /   0   0   0   0
CTB  84  52  87  55 /   0   0   0   0
HLN  89  58  92  59 /   0   0   0  10
BZN  90  53  94  55 /   0   0  10  20
WYS  80  41  83  44 /   0   0  20  20
DLN  86  52  88  53 /   0   0  20  20
HVR  87  54  93  58 /   0   0   0   0
LWT  80  54  86  58 /   0   0   0  10

&&

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

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