High Wind Warning 8, NWS Great Falls, MT

544 
WWUS75 KTFX 171802
NPWTFX

URGENT - WEATHER MESSAGE
National Weather Service Great Falls MT
1102 AM MST Fri Feb 17 2023

MTZ302-303-171915-
/O.CAN.KTFX.HW.W.0008.000000T0000Z-230217T2000Z/
Northern High Plains-Eastern Glacier, Western Toole, and Central
Pondera-
Including the following locations: Browning, Dupuyer, Heart
Butte, Cut Bank, Santa Rita, and Ethridge
1102 AM MST Fri Feb 17 2023

...HIGH WIND WARNING IS CANCELLED...

The risk for strong wind gusts in excess of 60 mph has ended, but 
gusts up to 50 mph are possible through this afternoon.

$$

Hoenisch

Area Forecast Discussion
National Weather Service Great Falls MT
1110 PM MST Thu Feb 16 2023

...Aviation Section Update...

.UPDATE...

Only adjustment made to the overnight period of the forecast was
to lower low temperatures in some wind-protected valleys of
Southwest Montana. This mainly includes the valley areas around
Bozeman, West Yellowstone, Wisdom, and the Elk Park region of
Interstate 15 in Jefferson County. Temperatures there are falling
a bit more than previously forecast, so have lowered lows there
about 5 to 8 degrees to better reflect temperature trends from
last night, putting overnight lows there at or below zero.

The remainder of the forecast appears to be on track. Mainly high
cloudiness will pass overhead with a passing disturbance. Gusty
westerly winds on the east slopes of the Rockies may decrease a
bit overnight as well, but they should increase once again by
mid-morning on Friday.
-Coulston

&&

.SYNOPSIS...

High pressure shifts across the region tonight for continued dry
conditions with increasing clouds through Friday morning. Breezy
to windy conditions persist across the plains, with localized
strong wind gusts along the Rocky Mountain Front. A northwesterly
flow aloft develops this weekend with increasing moisture
bringing some accumulating snow to mountain areas with snow
showers possible at lower elevations. A turn to more wintry
conditions with snow and much colder temperatures is likely next
week.

&&

.AVIATION...
1110 PM MST Thu Feb 16 2023 (17/06Z TAF Period)

VFR conditions prevail for the duration of this TAF period.
Increasing and lowering clouds, along with snowfall along The
Continental Divide, favor mountain obscuration. Winds/wind gusts
cause the greatest impact to aviation operations. Westerly winds
gust to 49KT at KCTB, tomorrow late morning and through the
afternoon. Strong gusty winds are forecast across portions of north
central and central Montana. Mountain wave activity is forecast. Low
Level wind shear conditions are included in the KHVR TAF. Generally
light winds are forecast for KHLN and KBZN. A south southeasterly to
south southwesterly wind component favors gusty winds up to 35KT at
KEKS. Aircraft encounter strong funneled winds through north-south
oriented mountain valleys and passes across southwest Montana.
- Fogleman

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

&&

.PREV DISCUSSION...
/ISSUED 435 PM MST Thu Feb 16 2023/

An upper level ridge extending north into western MT this
afternoon will flatten later tonight as the northern portion of a
splitting trough off the west coast moves into western Canada and
east across AB/SK Friday. At the surface, a low pressure trough
exists to the lee of the Canadian Rockies and Rocky Mtn Front and
will deepen tonight in response to the flatting ridge and
increasing westerly flow aloft before shifting east with the
shortwave energy moving across AB/SK Friday morning. The main
impact from this feature will be increased winds across most of
north-central MT tonight with strong winds (gusts greater than 55
mph) likely to be confined to areas from the Rocky Mtn Front east
to US-89, where winds will peak late tonight. There is some
potential for mountain wave enhancement to produce isolated gusts
in excess of 70 mph in a few locations just east of the Rocky Mtn
Front. Otherwise, clouds will increase across the area with the
influx of mid-high level moisture, but mainly dry conditions are
expected through early Saturday morning across all but areas near
the continental divide north of Lincoln to the Canadian border,
where some snow showers are possible beginning as early as Friday
afternoon.

Moving through the weekend, a slightly cyclonic NW flow aloft
develops across the region as upper level ridging amplifies in
the eastern Pacific with troughing downstream expanding across
western Canada. Increasingly unsettled but only slightly cooler
conditions develop as mid level moisture increases in the NW flow
with a fairly potent upper level jet nosing southward into
Northern Rockies by Saturday night and Sunday. Snow showers will
increase across the mountains Saturday and Sunday with periods of
accumulating snow likely over the mountains as embedded shortwave
disturbances moves through the area. There is some uncertainty
and spread among models with the track of the shortwave moving
through the area Saturday night, but this is a favorable set up
for locally enhanced snowfall across the Little/Big Belt and
Bridger mountain ranges. Models have trended up some with
precipitation coverage and amounts late Saturday into Sunday,
particularly across central MT and eastern portions of SW MT with
most areas now having a 50% or better probability for at least
some minor snow accumulation with similar probabilities for snow
accumulation greater than 2 inches limited to the mountains of
central and eastern portions of SW MT.

Confidence in an impactful period of winter weather next week
continues to increase as medium range model ensembles and cluster
analysis show broad support for the deepening and SW expansion of
the large scale Canadian trough into the NW US while Pacific
moisture continues to stream east across the region through the
early part of next week. There are still many details to be
resolved with timing and precipitation amounts but latest
guidance suggests an initial period of snow with colder
temperatures arriving Monday/Monday night before a more impactful
period of winter weather potentially develops with the arrival of
a deeper cold/Arctic airmass in the Tue/Wed period. Very cold
temperatures are likely to follow Wed through Fri of next week
with latest guidance indicating a better than 50% chance for
daytime temperatures near zero and low temperatures in the teens
below zero next Thursday and Friday. Hoenisch

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  30  41  31  41 /   0   0   0  30
CTB  25  39  25  39 /   0   0   0  10
HLN  18  39  25  39 /   0   0   0  30
BZN   0  33  10  33 /   0   0   0  30
WYS -14  26  -2  24 /   0   0   0  40
DLN   8  31  11  32 /   0   0   0  10
HVR  26  36  22  36 /   0  10   0  20
LWT  25  38  23  37 /   0   0   0  30

&&

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

http://www.weather.gov/greatfalls