Heavy Snow and High Wind in Nevada, December 22 to 24, 2021

Area Forecast Discussion
National Weather Service Elko NV
228 PM PST Wed Dec 22 2021

.SYNOPSIS...Winter weather has returned to the silver state as a
series of winter systems pass across the West. These systems will
bring rounds of precipitation with Thursday seeing the heaviest
precipitation. This can cause icy road conditions and impact
travel during the holiday season.

&&

.SHORT TERM...Today through Friday.

A frontal system will impact the West Thursday and Friday
bringing unsettled winter weather to the silver state. This system
is proving to be fairly complex as it brings a whole slew of
possible precipitation types to NV as it passes through. What is
most likely to occur is the lower valleys will see rain to a
rain/snow mix on Thursday that will transition to snow on Friday.
For the mid to higher valleys this is looking to be snow/rain mix
that will then transition to pure snowfall. This transition will
likely occur as the precipitation picks up along the cold front.
This transition time will be key to how much snow can actually
accumulate as a faster transition will allow much more snowfall
than a slower one. This question is most pronounced near Elko and
Spring Creek on Lamoille Summit. This summit does look like it
will transition sooner allowing for enhanced snow accumulation
that can lead to travel impacts. Thus the Winter Weather Advisory
was expanded to SW Elko to account for this. Another very
impactful curve ball that cant be ignored is the possibility of
freezing rain. This would require a narrow range of warm air aloft
to set up ahead of the cold front that also doesn't cool to fast
as the heavier precipitation starts. While this overall doesn't
look likely, and indeed similar events in the past did not yield
freezing rain, several of these ingredients do line up so the
chance cannot be ignored. So use extreme caution if rain is
observed while the air temperatures is at or below freezing. Back
to more likely snow occurrence, snow amounts are looking to be an
inch or less for the low valleys as these see mostly rain to a
mix. The mid valleys will see 1 to 4 inches and for the upper
valleys 2 to 5 inches. The mountains like always will be the
winner with half a foot to upwards of 2 feet possible. A Winter
Weather Advisory remains in effect for higher elevations where
these heavier snow amounts are expected. Be sure to use caution
while traveling as any snow or the refreezing of melted snow can
lead to icy conditions. Winds will also be breezy ahead of and
along the cold front. While not the strongest they can blow around
light objects, especially if those light objects are on icy
surfaces. Temperatures will begin to cool on Friday following the
passage of the cold front. This should see the low temperatures
become colder by 5 to 10 degrees while the daytime highs drop a
couple of degrees. Wind chill effects will make the apparent
temperature colder with the passage of this system.

.LONG TERM...Saturday through next Wednesday.

Active weather pattern continues throughout the long term period
and beyond, with a long wave pattern in control of the western
U.S. and periodic trofs rotating through the long wave. The
temperatures in the column will be colder throughout the period,
so while qpf amounts overall will be lower than in the short term
period, the snow making will be more efficient and accumulations
will be easier to come by, especially from Sunday and on. Best
probabilities for accumulating snowfall is Christmas Day through
Sunday morning and then again on Monday through Monday night,
where each storm could drop an additional couple of inches each
time into valleys, with higher amounts in the mountains. In
between systems, conditions remain unstable enough for flurries
and/or isolated to scattered light snow showers. Blowing snow
looks to be an issue throughout the long term period, especially
in the mountains, with snow being light and fluffy. Even in
valleys, 15 to 20 mph winds can be enough to reduce visibility and
transport the snow around. Sunday and Monday appear at this time
to be the best probability for more elevated gusty winds.

Saturday high temperatures will be in the 30's, but then go into a
cooling trend throughout the remainder of the longterm, and by
Wednesday are expected to be in the mid teens through the mid
20's. Low temperatures follow the same trend, with lows Sunday
morning in the teens and then by Tuesday and Wednesday morning
look to be in the single digits and possibly lower, with the
addition of new snowfall.

&&

.AVIATION...KWMC, KBAM, and KEKO could see an isolated shower or
two this afternoon. Showers generally are not expected to reduce
VIS below 6sm and CIGs will likely remain VFR, with a low
probability of tempo MVFR conditions. There is also a low chance
of occurrence of light freezing rain at the northern Airports. Use
caution if rain is encountered with below freezing air as this
may cause icy airport conditions.

A stronger system is expected to begin to move into KWMC on
Thursday morning, bringing rain and snow showers. These showers
will spread east/southeast through the afternoon into KBAM, KEKO,
and KTPH. MVFR conditions will be prevalent, with IFR CIGs/VIS
probable in the more moderate showers and a lower chance for LIFR.
Once again, there is a low probability (10%) chance for freezing
rain through Thursday afternoon, but kept out of the TAF's for
now.

&&

.LKN WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 10 AM Thursday to 10 AM PST Friday
for Northern Elko County-Ruby Mountains and East Humboldt Range.

Winter Weather Advisory from 4 PM Thursday to 10 AM PST Friday
for Northwestern Nye County-Southern Lander County and Southern
Eureka County-White Pine County.

&&

99/90/90