705
FXUS65 KTFX 251859
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1259 PM MDT Wed Jun 25 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Near to above normal temperatures will continue through the
   rest of the week.

 - Daily chances for afternoon showers and thunderstorms through
   Saturday.

&&

.UPDATE...
/Issued 834 AM MDT Wed Jun 25 2025/

Today it will be warm with isolated showers this afternoon and
evening across North-central Montana with the greatest coverage
along the Hi-Line. For the update PoPs were increased along the
Hi-Line to better reflect the latest Hi-res model guidance.
Hourly temperatures were re-run. The rest of the forecast is on
track. -IG

&&

.DISCUSSION...
/Issued 834 AM MDT Wed Jun 25 2025/

 - Meteorological Overview:

Southwest flow aloft will continue through the rest of the week
bringing near to above normal temperatures across the region
through Saturday. With just enough moisture and instability to
keep things going, there will be daily chances for afternoon
showers and thunderstorms through Saturday. The most notable and
widespread chance for showers and thunderstorms will correspond
with a weak shortwave arriving on Thursday with the potential for
some isolated severe thunderstorms across portions of north-
central into northeastern Montana. Saturday and Sunday will be the
transition period from southwest flow to an upper level ridge
giving way to general warm and dry conditions through the weekend.
By the start of next week, the ridge starts to build over the
western CONUS allowing for the potential of much warmer
temperatures across Montana through the start of next week.


 - Forecast Confidence & Scenarios:

Showers/Thunderstorms Today:

Generally weak dynamics will allow for some shower and
thunderstorm development across the Continental Divide into
portions of central and north-central Montana this afternoon. The
main concern with any thunderstorm this afternoon will be gusty
winds up to 40 mph. Otherwise, most locations will remain dry over
the next 24 hours.


Thunderstorms on Thursday:

SPC has continued a Marginal Risk for Blaine and Fergus counties
as well as the eastern portions of Hill, Chouteau, and Judith
Basin counties. Overall, the setup is a true to form marginal
risk. MLCAPE and shear are within the range of what typically
kicks off a few stronger to severe thunderstorms. The limiting
factor that gives pause to the severe potential is the anticipated
cloud cover Thursday morning. If the clouds stick around through
the mid to late morning this may be what keeps the afternoon from
getting too feisty. On the other hand, should the morning clouds
clear out, there is continuing suggestion from a few of the CAMs
that the potential for stronger storms may even extend into
eastern Cascade county beyond where the current Marginal Risk is
located. At this point in time, the main threat with storms that
develop on Thursday afternoon will be strong, gusty winds and
small hail.


Showers/Thunderstorms Friday and Saturday:

Isolated thunderstorms are expected to pop up Friday and Saturday
afternoon with Friday having more of a focus across central and
southwest Montana and Saturday being more isolated along the
Canadian border as well as portions of Gallatin and Madison
counties in southwest Montana. At this point in time, the threat
for severe weather both days is quite low with most showers
staying on the more benign side of things.  -thor


&&

.AVIATION...
25/18Z TAF Period

VFR conditions continue for all airfields throughout this 25/18Z
TAF period. Winds are, generally, light and variable, with KCTB
forecast to experience periods when winds gust southwesterly to 25
mph. This afternoon and evening, there is a slight (< 25%) chance
for showers and a few thunderstorms across higher elevations of
central and north central Montana. Virga should be expected.
Tomorrow afternoon and evening, there is a 30% to 40% chance for
showers and thunderstorms to move across the region from southwest
to northeast. With warming summer temperatures, density altitude
becomes and issue.
- Fogleman

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  84  54  81  55 /  10  20  40  20
CTB  79  53  76  53 /  20  20  20   0
HLN  83  55  80  54 /  10  20  40  20
BZN  84  49  84  50 /  10   0  20  20
WYS  72  36  75  39 /  10   0  10  10
DLN  78  49  80  48 /  10  10  30  10
HVR  85  55  84  54 /  20  20  20  20
LWT  79  52  79  51 /  10  20  40  40

&&

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

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