Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 282341
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
540 PM MDT Wed Oct 28 2020

...UPDATED AVIATION SECTION...

.SYNOPSIS...

A few light showers are possible through this evening across the
mountains and eastern portions of north-central MT. Otherwise,
dry conditions prevail with winds increasing for some areas on
Thursday as temperatures continue to moderate. Gusty winds and
another chance for mainly mountain showers are expected as a
frontal system moves across the region Friday. After some slight
cooling Saturday, mild and at times windy conditions redevelop
through early next week.

&&

.DISCUSSION...

Area remains under a WNW flow aloft around ridging centered off the
west coast with the main upper level jet situated to the north
across SW Canada. Some very light rain/mountain snow showers
remain possible across mainly northern portions of the forecast
area through this evening. Otherwise, dry conditions prevail across
the area. Surface pressure gradient across the Rockies will increase
late tonight through Thursday morning, bringing some gusty winds
to mainly areas along the east slopes by Thursday morning.

A more potent shortwave disturbance moves over the ridge and
drops SE across the region Friday with surface low pressure
emerging in southern AB and moving east into souther SK while an
associated cold front moves across central and SW MT Friday
afternoon. Main impact from this system will be increased winds
across the entire area Friday with particularly windy conditions
expected across north-central MT as a mid-level wind maximum of
60-70kts is progged to move across in association with the
shortwave and surface frontal feature. Will issue a High Wind
Watch for areas from Glacier county south through Cascade and
Judith Basin counties to highlight the potential for strong wind
gusts Friday. Precipitation will be limited to mainly areas along
the continental divide with just a small chance for showers
further east with the frontal passage and later Friday night as
flow aloft turns more northwesterly again.

Slightly cooler temperatures follow on Saturday with lighter winds
also expected. The offshore upper ridge shifts inland this weekend
with more substantial warming expected into early next week before
the ridge begins to flatten. Dry conditions should prevail
through at least the first half of next week with windy conditions
likely to develop as the ridge begins to flatten. Medium range
models show a zonal westerly flow for mid to later next week, with
temperatures cooling back to seasonal averages and increasing
chances for light precipitation. While confidence is low at this
time range, there is a growing trend among longer range models
for a transition back to colder/wintry conditions next weekend.
Hoenisch

&&

.AVIATION...
540 PM MDT Wed Oct 28 2020 (29/00Z TAF period)

The strong northwest flow aloft will continue mountain wave
turbulence over the area through the next 24 hours, along with low
level wind shear across much of North Central and Central Montana.
Otherwise, VFR conditions will prevail across the area with areas of
mid and high level cloudiness passing overhead. A weak frontal
boundary will move east of the Rocky Mountain Front and across the
plains through 12Z, which will spread breezy and gusty westerly
downslope winds across that area.  Coulston

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  34  50  29  56 /  10  10   0   0
CTB  29  44  26  50 /  10  10   0  10
HLN  34  54  29  56 /   0   0   0   0
BZN  25  48  22  56 /   0   0   0   0
WYS   8  46  15  47 /   0   0   0   0
DLN  27  55  27  58 /   0   0   0   0
HVR  26  46  25  53 /  10  10   0   0
LWT  32  49  29  56 /  10  10   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from Friday morning through Friday evening
Cascade...Eastern Glacier...Eastern Pondera...Eastern Teton...
Judith Basin...Northern Rocky Mountain Front...Southern Rocky
Mountain Front...Toole.

&&

$$

http://www.weather.gov/greatfalls


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