284
FXUS65 KTFX 031458
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
858 AM MDT Thu Jul 3 2025

.KEY MESSAGES...

 - Showers and thunderstorms possible this afternoon across
   southwest Montana into portions of central Montana.

 - Potential for more widespread rain Friday and Saturday.

 - Mild temperatures over the weekend before warming up by the
   middle of next week.

&&

.UPDATE...

Today it will be another warm day with showers and thunderstorms
in Southwestern Montana up to Central Montana today. For the
update temperatures across the area were increased to reflect the
latest hi-res model guidance. PoPs across Southwestern Montana
into Central Montana were increased to reflect current radar
imagery and the latest hi-res model guidance. The rest of the
forecast is on track. -IG

&&

.DISCUSSION...
/Issued 531 AM MDT Thu Jul 3 2025/

 - Meteorological Overview:

Another round of afternoon showers and thunderstorms are expected
this afternoon and evening. Isolated showers are possible across
north-central Montana but the main focus will be south of Highway
200 particularly into southwest Montana. Similar to the previous
days, the main concerns will be lightning and strong, gusty
winds with a slight chance for small hail (<0.5"). Otherwise,
Thursday will be another warm day, particularly across north-
central Montana with highs in the mid 80s to mid 90s.

An upper level trough moves across the region Friday into Saturday
bringing cooler temperatures and a chance for widespread
precipitation. Temperatures will remain closer to normal through
the weekend before a slow warming trend starts early next week as
upper level ridging builds across the western CONUS.


 - Forecast Confidence & Scenarios:

Thunderstorms Today:

The greatest concern for thunderstorms this afternoon will be in
southwest Montana where DCAPE is enough to cause problems with
any thunderstorm that develops. Around thunderstorms this
afternoon, wind gusts of 40-50 mph are possible with some isolated
higher gusts possible. One thing to watch will be any collapsing
thunderstorm which may let out a strong outflow causing gusty
winds miles away from the parent thunderstorm. Another concern
this afternoon will be lightning. Already yesterday a few
wildfires were sparked by lightning strikes and there is a concern
we could see a repeat again this afternoon. Conditions are not
dry enough to raise alarms but dry enough that those recreating
outdoors and setting off fireworks need to be extra careful to
prevent wildfires from starting.


Widespread Rain Friday and Saturday:

Rainfall amounts have continued to back off with successive model
runs, a trend that seems to be moderating the previously higher
amounts that were seen in the earlier model runs. As of right now,
the current storm total amount probabilities are as follows:

  - >0.10": 60-80% chance
  - >0.25": 50-70% chance
  - >0.50": 30-50% chance
  - >0.75": 10-30% chance
  - >1.00": Generally less than 10% chance except for the island
    ranges of central Montana with a 10-20% chance

It is worth noting that some of the higher amounts seen in the
previous model runs may still be possible. But the catch is the
higher amounts will be more localized and dependent on where more
robust convection is able to set up. Thus the lower amounts are
seen as the most likely scenario with the built in caveat that
localized heavier amounts are always on the table should a band of
stronger showers develop.


Warming Back Up Next Week:

Ensemble clusters are in moderate agreement that an upper level
ridge will build over the western CONUS, allowing for warmer
temperatures to slowly return to Montana. The main uncertainty is
the exact placement and strength of the ridge which will have
impacts on how warm it gets and whether or not any monsoonal
moisture is able to make its way up here which could cause some
afternoon thunderstorm activity if it pans out.  -thor


&&

.AVIATION...
03/12Z TAF Period

Isolated showers/virga and a few thunderstorms over Central and
North- central Montana will gradually fade shortly after sunrise,
but another area of showers over Idaho will be moving into
Southwest Montana later this morning. The more widespread showers
and thunderstorms will develop later this afternoon and evening,
mostly impacting Southwest Montana and central areas along and
south of a KHLN to KLWT line. The stronger cores will produce
erratic, gusty winds, brief downpours, and isolated instances of
hail. Westerly winds will become gusty at times over the plains
today, especially along the Rocky Mountain Front where gusts over
35 kts will be common. - RCG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  92  55  77  54 /  10   0  30  70
CTB  84  48  74  50 /   0   0  10  60
HLN  89  57  74  51 /  30  20  70  70
BZN  92  54  79  49 /  40  30  80  70
WYS  79  45  69  39 /  40  40  90  60
DLN  84  50  72  45 /  50  30  90  60
HVR  96  53  83  54 /   0   0  10  60
LWT  85  55  75  49 /  20  30  40  80

&&

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

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