236
FXUS65 KTFX 061504
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
904 AM MDT Sun Apr 6 2025

.KEY MESSAGES...

 - Temperatures trend warmer through Monday before a Pacific cold front
   trends the region closer to normal for Tuesday and Wednesday.

 - Gusty winds at times Monday through Wednesday, mostly on the
   plains.

 - A quick return to warmer and dry conditions late week before
   another period of cooler weather next weekend.

&&

.UPDATE...

It will be warm and sunny today across North-central, Central, and
Southwestern Montana. For the update, high temperatures across
North-central, Central, and Southwestern Montana were increased
to better reflect current observations, trends, and the latest
model guidance. Wind speeds across the area were adjusted today to
better reflect current observations and trends. The rest of the
forecast is on track. -IG

&&

.DISCUSSION...
/Issued 536 AM MDT Sun Apr 6 2025/

 - Meteorological Overview:

Amplified upper level ridging across the west, stretching well up
into Canada, will being to slump late today as a series of upper
level disturbances move in across the Pacific Northwest beginning
Monday. Temperatures continue to trend warmer in the meantime,
peaking on Monday for most before a Pacific cold front moves
through sometime late Monday or Monday night cooling the region
closer to normal for mid-week. A subset of guidance sneaks weak
instability along the Continental Divide and into Central Montana
Monday afternoon, giving a low-end chance for a shower or isolated
thunderstorm.

The larger concern going into Tuesday and Wednesday will be for a
period of gusty winds, mostly across the plains thanks to a zonal
flow aloft. The period for the strongest winds across the western
plains looks to be Tuesday afternoon, while eastern plains locations
are trending toward Wednesday morning as the gustiest period. All
that said, forecast soundings do not favor strong winds at this time
(Gusts of 50 kts or sustained winds of 35 kt), with max gusts mostly
in the 40-50 mph range at their strongest.

The other concern will be for a few instances of showers and snow
showers, mostly in the mountains Tuesday into Wednesday. While
enough instability will exist for a rumble of thunder, it appears
to be an isolated risk at this time. Light snow amounts and timing
of snow showers (mainly during the day) does not appear conducive
for widespread impacts at this time.

Zonal flow transitions back toward upper level ridging briefly
Wednesday night through at least Friday morning, allowing for
temperatures to warm back up and keep the region dry. Uncertainty
in specifics increases toward the weekend, but a trend back closer
to average temperatures and active weather is favored. -AM

 - Forecast Confidence & Scenarios:

Wind Tuesday and Wednesday:

Probabilistic guidance has trended upward with chances for a 58 mph
gust around Cut Bank on Tuesday. Deterministic guidance largely
does not support this however, with only a small subset resulting in
strong gusts. As such, a High Wind Watch is not being considered at
this time for the Cut Bank area Tuesday afternoon.

Snow amounts in the mountains:

Marias and Chief Joseph Passes have the best chance for briefly
impactful snow. Reasonable high end amounts for these passes (90%
chance for less than the given amount) is roughly 3 inches from late
Monday night through Wednesday afternoon. It should be noted that
even in this higher end scenario, the chance for any impacts is low
at these locations.

Late week warm-up:

A transition back to above normal conditions is strongly favored
late week. The chance for a 70F high Friday is at or greater than
50% for most lower elevation locations.

Next weekend:

Cluster guidance is in relatively good agreement that troughing will
be around across the Northern Rockies next weekend. Specifics such
as magnitude and timing of the troughing is low confidence at this
range, however. Regardless, troughing across the Northern Rockies
would favor a cooler period with opportunities for precipitation. -AM

&&

.AVIATION...
06/12Z TAF Period

VFR conditions will prevail across the CWA through the period.
Do expect increasing mid and high level clouds to move into the
CWA from west to east, mostly after 01z Mon. Brusda

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  65  36  67  40 /   0   0   0  20
CTB  63  32  64  37 /   0   0   0  10
HLN  65  35  66  38 /   0   0  10  50
BZN  60  30  62  35 /   0   0   0  40
WYS  53  20  53  30 /   0   0   0  60
DLN  62  31  61  35 /   0   0   0  40
HVR  66  31  72  38 /   0   0   0  20
LWT  59  34  66  39 /   0   0   0  30

&&

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

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