012
FXUS65 KTFX 141132
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
532 AM MDT Mon Jul 14 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Warm temperatures will continue across southwest Montana today
   while a strong cold front starts to make its way in from the
   north bringing cooler temperatures to north-central Montana.

 - Showers and thunderstorms will start along the Hi-Line by the
   late afternoon and become more widespread across the region by
   Tuesday morning.

 - Cooler temperatures and a widespread chance for rain will
   continue across the region Monday through Wednesday.

 - Return to more seasonable temperatures and dry conditions by
   the weekend.

&&

.DISCUSSION...
/Issued 259 AM MDT Mon Jul 14 2025/

 - Meteorological Overview:

Over the next couple days an upper level trough will make its way
across the state of Montana bringing a chance for widespread
rain and even some high-mountain snow. Temperatures today will be
the dichotomy of warmth across the southwestern portion of the
state while the northern portion of the region starts out warm
before a strong cold front makes its way into central Montana by
the overnight hours. The first wave of precipitation will start
this evening as showers and thunderstorms fire off across the Hi-
Line and gradually become more widespread by early Tuesday
morning.

Rain, heavy at times, will continue through most of the day on
Tuesday with the potential for snow showers above 8000ft. Rain
will slowly taper off from northwest to southeast on Wednesday as
the trough starts to exit the region by Wednesday evening.

Behind the trough, quasi-northwest flow will help moderate
temperatures Wednesday afternoon into Thursday afternoon. This
gradual warmup will be slowed by an incoming shortwave that
arrives Thursday afternoon and brings another chance for more
isolated to scattered showers and thunderstorms. Behind the
shortwave upper level ridging starts to build over the weekend
allowing seasonable temperatures and dry conditions to return to
the region.


 - Forecast Confidence & Scenarios:

Severe Weather Potential Today:

Similar to what occurred late Sunday night with storms coming down
into Canada and making their way across the northern portions of
the Hi-Line, a similar set up is expected this afternoon and
evening ahead of the cold front. There is currently a marginal
risk for severe thunderstorms today and the main concern will be
wind gusts up to 65 mph. As of now, storms are expected to cross
the International Border between 6-8PM and move east-southeast
across the Hi-Line.


QPF Monday-Wednesday:

In general, QPF amounts have remained roughly the same compared to
previous forecast runs. The heaviest precipitation is still
expected along the Rocky Mountain Front as well as portions of
central Montana including the Judith Basin, southern Chouteau, and
Fergus county area.

There is a slight hesitancy that the NBM QPF amounts are running
a little high in some places. Some of the uncertainty is due to
the disconnect between the deterministic amounts and the
probabilities from the NBM. Right now the NBM has wide patches of
1"+ across central and north-central Montana but
probabilistically, the NBM says there`s only a 30-50% of reaching
1" and only a 40-60% chance of these locations receiving 0.75" or
more.

The most likely scenario that I see occurring is many locations
north of a line between Helena and the southern Fergus county
border will receive at least 0.5" through Wednesday. Locations
along the Rocky Mountain Front and portions of central Montana
including the Judith Basin and Fergus county areas have the
highest chance to reach 0.75". Higher amounts are most likely
going to be fairly localized and very dependent on where the
stronger embedded storms form within the band of precipitation. In
a lot of ways this thought process justifies the 30-50% chance
from the NBM of all locations in central and north-central Montana
seeing 1" rain. It is certainly possible but it is generally less
likely.


Snow/Wind Along the Rocky Mountain Front:

Snow levels will start out at 10-12,000 feet late Monday evening
and gradually drop behind the cold front down to 8-10,000 feet by
Tuesday morning. 700mb temperatures continue to build confidence
in snow falling at the highest peaks of Glacier National Park. At
this time, snow is not expected to impact Logan Pass or locations
below pass level. Thus the main impacts will be to those
recreating in the backcountry. Winds will also pick up out of the
northeast along the Rocky Mountain Front as the cold front makes
its way south. At this point in time, winds east of the divide are
not strong enough to warrant any high wind products, however,
wind gusts up 50 mph should be expected for anyone recreating in
the area. -thor


&&

.AVIATION...
14/12Z TAF Period

Several concerns will be around this TAF period. Initial concerns
will be for showers and thunderstorms this afternoon across SW MT,
mainly along and south of I-90. Meanwhile, a cold front will be
pushing south out of Canada beginning late afternoon, bringing gusty
northerly winds along and behind it. Showers and thunderstorms look
to develop near and behind the front for a few hours before
precipitation begins a transition to be more stratiform in nature.
As this happens, ceilings will lower from north to south across the
region. The developing low clouds will cause increasing mountain
obscuration from north to south late today into tonight. -AM

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  91  53  57  49 /  10  80  90  70
CTB  74  48  53  44 /  40  90  80  40
HLN  95  55  62  49 /  10  60  80  80
BZN  95  54  72  48 /  10  30  80  80
WYS  84  44  77  41 /  30  20  70  70
DLN  90  51  75  47 /  10  10  70  50
HVR  85  52  62  47 /  20  80  70  50
LWT  90  50  57  46 /  10  70  90  90

&&

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

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