Winter Storm and Avalanche in Nevada, March 1 to 4, 2018

Area Forecast Discussion
National Weather Service Elko NV
356 PM PST Thu Mar 1 2018

.SYNOPSIS...A major winter storm will impact Nevada beginning
tomorrow afternoon and will persist into the weekend for central
Nevada. Widespread and significant snowfall is expected. This will
cause roads to become slick and snow covered, leading to
dangerous travel at times. The storm will slowly exit the region
through Saturday night. Below average temperatures and dry weather
is expected for the start of next week.

&&

.SHORT TERM...Today through Sunday. Confidence remains high for
a major winter to storm to impact the region beginning tomorrow
and persisting through Sunday. Low to moderate confidence exists
for forecast snow amounts in Humboldt, and northern Lander/Eureka
Counties. High confidence exists elsewhere, especially across the
highway 50 corridor.

Today - Strong southerly winds are still widespread across the
region. The highest gusts have been in the 40-55 mph range and
mostly confined to the higher elevations. Winds will remain strong
until the frontal band moves across the reigon later this evening
through tomorrow morning.

Valley rain and mtn snow is quickly streaming into Humboldt
County with snow being observed above 65000 feet. Snow levels will
gradually fall initially, before crashing later this evening and
night. The tricky part of the forecast will be for how long rain
mixes with snow at the onset. Earlier changeover for WMC/Humboldt
Co, more snow and vice versa. Current thinking is light rain at
the onset and then quickly change to snow due to
diabatic/dynamical effects. A quick 2-6 inches of snow will be
possible, with closer to 3 inches near WMC through Friday morning.

As the large elongated upper level trof slowly pushes eastward
through Friday morning, energy and the associated frontal band
will move east. Heavy snow and gusty winds will accompany the
bndry as it moves into the Elko and Spring Creek region. A quick
several inches will be likely in Elko, with the heaviest snow
during the morning Fri. For Spring Creek, Lamoille, Lee, Jiggs
etc...Snow will linger into the evening and likely into Sat
morning, due to upslope enhancement. In fact, the overall upslope
component for the storms has improved, meaning higher confidence
for significant amounts of snow in these areas. Localized amounts
amounts will approach 12 inches in these areas. The Ruby Mtns,
especially the southern portion of the range, could see 1-2 feet.
Favored NW flow regions within the Ruby mtns could see greater
that 2 feet.

By Fri late morning through the evening, the frontal band will
slide south and settle into central NV. This is where the greatest
impacts are expected. Significant snow is expected, with
widespread accumulations nearing 1 foot. Localized and favorable
locations like Eureka, Austin, Ruth, could see totals nearing 18
inches. This will cause dangerous and nearly impossible travel
Friday night through Saturday.

The front will be in no hurry to move, due to the slow movement of
the associated upper level trof. Additional moisture and energy
will be traversing through central NV, keeping the snow going
through at least Sat aftn/eve.

Finally by Sunday morning, the bulk of precip will have exited
the state. As the trof axis and some weak energy slides across
northern NV, additional light snow showers with little to no
accumulation are expected.

This will likely be the largest and most significant winter storm
of the season for many locations. Travel is not recommended
during the night where the heavier snow is forecast. Heavy
snowfall rates and cold temps will create an environment for snow
packed roads. Gusty winds will also cause patchy areas of
blowing/drifting snow, especially across passes/summits. If you
must travel, you should have an emergency roadside kit and be
prepared for adverse/dangerous driving conditions.

.LONG TERM...Sunday night through next Thursday. Model agreement is
good through about Tuesday of next week. And it seems to be a
generally dry stretch of days upcoming. There is still a lot of
upstream energy out over the Pacific Ocean and by late Tuesday,
the models are having a difference of opinion. Seems that there
will be another storm moving in however Wednesday may or may not
be that day.

Sunday through Sunday night. There could be some lingering shower
activity Sunday, tapering off quickly Sunday night. The axis of
the low pressure wave will be passing over the 4-corners area of
the country, well east of the state, and mild ridging will begin.
High temperatures will range from the mid 20s to the mid 30s. Low
temperatures will range from the near zero to the single digits
above zero.

Monday through Tuesday night. This is expected to be a dry
period. A deepening low pressure area will nearly close off out
over the Pacific Ocean west of northern California. Ridging over
the Great Basin will be of moderate amplification. High
temperatures will range from the 30s to around 40 degrees. Low
temperatures will range from the single digits to the teens.

Wednesday through Thursday. Model agreement suffers at this
juncture. Both the ECMWF and the GFS now propose a dual-center
trough structure and the GFS has reversed its depiction of a
spread of QPF all across the LKN CWFA. The later timing is now
closer to that of the ECMWF which was much drier on model runs 24
hours ago. It is likely that at least mild ridging will continue
for Wednesday. However will gingerly reduce pops across the
eastern portion of the LKN CWFA and keep limited chances for
precipitation going towards western Nevada. High temperatures will
generally rise to around 40 degrees. Lows will generally be in the
20s.

&&

.AVIATION...A major winter storm will be moving through northern
and central Nevada today through Saturday. This will bring MVFR
to IFR ceilings to all terminals through to course of the storm
system. Snow and blowing snow is expected at all terminals. This
can cause reduced visibilities of MVFR to IFR and at times
drastically reduced visibility of VLIFR. Gusty wind to 40kts is
expected at all terminals with 50kt gusts possible briefly at
KELY just before the frontal passage at KELY around 08z Friday.

&&

.LKN WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 10 PM this evening to noon PST
Saturday for Northern Elko County-Ruby Mountains/East Humboldt
Range-South Central Elko County-Southwestern Elko County.

Winter Weather Advisory until 4 PM PST Friday for Humboldt
County-Northern Lander County and Northern Eureka County.

Winter Storm Warning from 10 AM Friday to 4 PM PST Saturday for
Southeastern Elko County.

Winter Storm Warning from 4 AM Friday to 7 PM PST Saturday for
Northeastern Nye County-Northwestern Nye County-Southern Lander
County and Southern Eureka County-White Pine County.

&&

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