651
FXUS65 KTFX 032007
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
207 PM MDT Thu Apr 3 2025

.KEY MESSAGES...

 - Snow diminishes for northern areas this evening, but wet,
   slushy road surfaces may refreeze and become slippery near and
   after sunset.

 - Snow shower activity and even a few rumbles of thunder
   are expected in southwest Montana by this evening, with some
   localized heavier areas of snow, especially in Madison and
   Gallatin counties.

 - Gusty northerly winds will move through Southwest Montana
   this evening, some areas will see gusts up to 40 mph at times,
   especially in the Townsend, Dillon, and Ennis areas.

 - A warming and drying trend then push temperatures back above
   average this weekend into early next week.

&&

.DISCUSSION...

 - Meteorological Overview:

Snow is gradually tapering off in northern areas this afternoon
while snow shower activity picks up in Southwest Montana amid weak
instability. Localized areas of heavy snow can be expected
through the evening hours, especially over Madison and Gallatin
counties where snowfall rates my exceed a half inch per hours at
times.

All areas observing wet road surfaces during the afternoon and
early evening hours will be susceptible to refreezing and becoming
slippery. Also, partial clearing of skies over the plains may
encourage patchy fog development, although most locations have
less than a 30% chance for visibility falling below a half mile.

Ridging aloft begins to build in heading into the weekend, but
northwesterly flow aloft may send some passing mid- and higher
level clouds moving through the area and keep temperatures on the
cooler side for the next day or so. Regardless, expect high
temperatures to warm 10 to 20 degrees above average by Monday.

Ensembles remain in good agreement with the ridge being flattened
some late Monday through Wednesday, allowing some unsettled
weather to pass through the Northern Rockies. Temperatures will
still be mild, it will just be windier with increasing chances for
scattered showers and some mountain snow. - RCG

 - Forecast Confidence & Scenarios:

Snow and winds this afternoon and tonight...

Snow is decreasing in a north to south fashion this afternoon and
the advisories along the Hi-Line were let go. No changes were
made to the advisories along the Southern Rocky Mountain Front and
the Little Belts with some snow still expected this afternoon in
addition to refreezing of wet surfaces around sunset. Snow over
the Little Belts fell a little below expectation, likely due to a
lower froude number in this wind set up.

Southwestern areas will be the bigger concern going forward with
the increasing snow shower activity and potential convective
enhancement. Some of the heavier snow showers will have localized
snowfall rates north of a half inch per hour. This will be
especially true in Madison and Gallatin counties where the current
winter weather advisories are going into effect this afternoon.

Southwestern areas will also see at least a brief period of
stronger winds, especially within the narrow north to south
oriented valleys, including the Dillon, Ennis, and Townsend areas
where gusts may approach and exceed 40 mph at times. - RCG

Winds Tuesday and Wednesday...

NBM probabilistic guidance indicates mostly a 50 to 80 percent
probability of 50+ mph wind gusts both days for the Rocky Mountain
Front and east into the Cut Bank area, with a 30 to 50 percent
probability of exceeding 70 mph wind gusts right along the Front.
These probabilities warrant monitoring for potential High Wind
highlights there. Elsewhere across North Central, Central, and
Southwest Montana, the probabilities of 50+ mph wind gusts
increase Tuesday into Wednesday, ranging mostly between 20 and 50
percent on Wednesday, which will also need to be watched.
- Coulston

&&

.AVIATION...
03/18Z TAF Period

A cold front pushing southward across Central Montana is causing
a mix of VFR to IFR conditions in a band snow and fog. Conditions
will gradually improve through the afternoon for KGTF/KCTB/KHVR.
On the other hand, conditions will deteriorate this afternoon and
evening as the frontal band of snow moves through Southwest MT
including KLWT/KBZN/KEKS. Weak instability may cause isolated
bands of convective snow along and south of I-90, with low
confidence but potentially significant impacts to afternoon
flight operations at KBZN. The frontal passage is also associated
with a shift to northerly winds gusting to 25kt for 1-3 hours.

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  32  18  43  23 / 100  30   0   0
CTB  31  13  41  22 / 100  10   0   0
HLN  41  20  44  23 /  70  50   0   0
BZN  41  20  38  17 /  80  80  20   0
WYS  38  13  38   7 /  60  60  20   0
DLN  42  21  41  21 /  60  80  10   0
HVR  36  16  43  21 / 100  10   0   0
LWT  35  16  37  21 / 100  50   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM MDT this evening for Southern
High Plains-Southern Rocky Mountain Front.

Winter Weather Advisory until midnight MDT tonight for Little
Belt and Highwood Mountains.

Winter Weather Advisory until 3 AM MDT Friday for Big Belt,
Bridger and Castle Mountains-Gallatin Valley-Gallatin and
Madison County Mountains and Centennial Mountains-Madison River
Valley.

&&

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