Area Forecast Discussion
Issued by NWS Great Falls, MT

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49
953
FXUS65 KTFX 231451
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
851 AM MDT Mon Jun 23 2025

.KEY MESSAGES...

 - Cooler weather will continue through today before gradually
   warming up through the week.

 - Daily chances for isolated to scattered afternoon showers and
   thunderstorms through the remainder of the work week.


&&

.UPDATE...

A surface pressure trough this morning can continue to produce a
few isolated showers across North-Central MT and the Continental
Divide this morning. Fog is currently lifting with surface heating
from the sun kicking in. Though, satellite trends shows fog
around the West Yellowstone area can linger for a few more hours
this morning. Isolated showers and thunderstorms move in this
afternoon, particularly across North-Central MT. Thunderstorm
develop doesn`t look robust. -Wilson


&&

.DISCUSSION...
/Issued 533 AM MDT Mon Jun 23 2025/

 - Meteorological Overview:

The system that has brought rain and snow to our region over the
past couple days will continue its departure to the east leaving
just enough moisture behind to allow for isolated to scattered
showers and thunderstorms this afternoon. Otherwise, no
widespread significant moisture is expected through the rest of
the day.

Behind this system, southwest flow will set up and remain through
much of the week allowing temperatures to moderate back to near to above
normal through at least Friday. Throughout the week, weak
shortwaves are expected to move through providing just enough
moisture and forcing to kick of daily afternoon showers and
thunderstorms across the region.


 - Forecast Confidence & Scenarios:

Fog This Morning:

There is still a concern for fog developing this morning across
the southwest valleys and portions of the northern plains. A
couple areas of fog have started to show up on satellite in
southwest Montana but so far conditions have either stayed just
dry enough or just cloudy enough to prevent any widespread fog
from developing. The prevailing thought is the fog is unlikely to
be widespread or dense enough to warrant any advisories but
motorists should be prepared to encounter patches of low
visibility in fog-prone areas that received rain and/or snow last
night.


Daily Thunderstorm Risk:

There will be a daily chance for isolated to scattered afternoon
thunderstorms across our region through the work week. For the
most part, little in terms of accumulation is expected although
locally higher amounts are possible under heavier showers.

As of now, there is no one day in particular this week that
stands out with the potential for severe weather across our
portion of Montana. Generally we can expect typical afternoon
thunderstorms with the potential for one or two stronger storms
that may produce gusty winds and small hail. But otherwise the
dynamics are generally lacking in our region for severe weather.


Potential Warmup Next Week:

There is increasing agreement between the models for warmer
temperatures arriving by early next week. Ensemble clusters point
towards a ridge building over the western CONUS starting this
weekend and lasting through at least Tuesday. As of now, it is too
early to tell exactly how hot it will get. But the latest model
guidance suggests there is a greater than 70% chance for highs
exceeding 85 and a 30-50% chance of highs exceeding 90 across the
plains and valleys of north-central, central, and southwest
Montana early next week.



&&

.AVIATION...
23/12Z TAF Period

Potential for fog development exists at most terminals for a
brief period early this morning, though surface winds to around
10 kts across north-central MT and lingering scattered mid-level
clouds across southwest MT remain a limiting factor, with lower
river valleys (including KHVR) and higher elevations basins
(including KWYS) having the highest probability for fog impacts.
Next disturbance rotating through the Northern Rockies will bring
an increase in mid-level clouds again late this morning with a few
showers across N-central MT and somewhat breezy west winds
developing by this afternoon. Hoenisch

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  69  43  79  49 /  20  20   0  10
CTB  65  40  75  45 /  20  20   0   0
HLN  69  44  79  50 /  30  20  10  10
BZN  71  39  78  43 /  20  20  10  10
WYS  61  25  69  30 /  20  20  20  10
DLN  64  36  72  40 /  20   0  10   0
HVR  71  45  79  50 /  20  20   0   0
LWT  66  41  75  48 /  20  20  10  10

&&

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

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