High Wind and Winter Weather in Nevada, January 2 to 4, 2025

Area Forecast Discussion
National Weather Service Reno NV
153 PM PST Thu Jan 2 2025

.SYNOPSIS...

* Quiet weather today through early Friday morning provides a good
  travel window over the Sierra ahead of a fast moving storm.

* Expect winter travel impacts for the Sierra on Friday from late
  morning through late evening, with gusty winds, mountain snow
  and valley rain.

* After a cooler and drier weekend, a reinforcing cold front may
  bring light shower chances and increased winds early next week.

&&

.DISCUSSION...

Today's dry and mild weather will give way to a fast moving but
relatively robust storm for Friday. For Sierra travel, the best
windows to avoid snowy and hazardous conditions would be to
complete the trip by early Friday morning or wait until Saturday.

Otherwise on Friday, expect rapidly worsening conditions by mid-
late morning. Winds will increase late tonight in higher
elevations and mix down to valleys for Friday morning, with a 3-6
hour period of downslope enhancement during the day prior to the
onset of precip along a cold front boundary. Wind advisories are
in place for the eastern Sierra and into western NV from the Reno
area southward to Mineral County, to highlight this enhanced wind
potential. Winds don't look to be quite as strong compared to the
previous wind event last Sunday, but still sufficient for land/air
travel and recreation impacts.

Forcing with Friday's storm precip rates will likely be strong
enough to pull snow levels down to near 5500 feet in northeast CA
and 6000 feet around Tahoe. Enhanced snowfall rates of 1-2"/hour
are anticipated with the main snow band, which would be sufficient
for daytime accumulation of snow on the main passes from
northeast CA southward to the Tahoe region. Therefore we issued a
Winter Weather Advisory for these areas--see the advisory message
at weather.gov/reno for more details on snow amounts. As colder
air continues filtering in during the afternoon, snow shower bands
behind the front are likely to fill in across the advisory areas,
producing travel impacts for the PM commute into Friday evening.
Farther south into Mono County, the precip band loses some of its
punch as it moves through--the higher elevations west of US-395
could still end up with 3-6" of snow with a couple inches possible
for higher passes along US-395. These amounts are below advisory
levels for Mono County, with limited impacts since the high Sierra
passes are in seasonal closures.

For western NV, rain or a rain-snow mix is likely to arrive by
early Friday afternoon, with peak precip rates between 2-6 pm.
This timing could produce PM commute travel issues, especially for
foothill locations near or above 5000 feet where snow is more
likely to accumulate on roads. Ensemble guidance projections show
potential for a burst of 1-3" snow in these foothill elevations
also including Virginia City, and if these trends are maintained
(especially if the peak precip arrives near/after sunset) an
advisory may be needed for far western NV. Lower valleys in
western NV will see mostly rain (0.10-0.25" around Reno-Sparks-
Carson Valley and Pershing County, mainly 0.10" or less for much
of Churchill, Mineral-Lyon counties), but may end as a rain-snow
mix by early evening. Wet roads could develop some icy patches
late Friday night if not able to dry out after skies clear out and
temperatures drop below freezing.

For this weekend, drier and cooler conditions are expected as
a rather flat ridge sets up over CA-NV, with highs near early
January averages of upper 30s-mid 40s Saturday, then edging up
by 3-7 degrees on Sunday. A slider-type system looks to drop
southward into NV on Monday with possible light showers, followed
by brisk and chilly conditions Tuesday. Strong NE-E wind gusts
are projected to develop for Sierra ridges Tuesday into Wednesday
as a more amplified high pressure ridge sets up off the CA coast.
MJD

&&

.AVIATION...

* VFR conditions and light winds prevail through this evening,
  followed by increasing ridge top/FL100 winds after 07Z late
  tonight producing areas of mountain wave turbulence and periods
  of LLWS near/east of the Sierra crest.

* Wind impacts on aviation will peak on Friday with Sierra ridge
  top/FL100 wind gusts of 70-85 kt leading to more widespread
  mountain wave turbulence all day, along with LLWS mainly prior
  to 20Z. Surface wind gusts at the main terminals increase to
  south 30-35 kt between 13-16Z, except around 18Z at KMMH. These
  gusts could reach 40-45 kt at times for the far western NV sites
  on Friday between 18-00Z, with wind directions varying from SE
  to SW including rotor potential.

* In addition to winds, CIGS/VIS will quickly drop to IFR/LIFR for
  KTVL/KTRK on Friday mainly between 18Z-00Z due to onset of
  SN/+SN. These conditions then arrive to KMMH mainly between
  00-04Z Friday evening. Runway snow accumulations could reach
  1-3" for these sites, with -SHSN lingering until around 06Z. For
  western NV terminals, MVFR-brief IFR conditions with mountain
  obscurations are most likely between 22-02Z due to onset of RA.
  While -SN may mix in near the end of this precip band and linger
  until 04Z, no runway snow accumulations are anticipated at
  KRNO/KCXP/KMEV.

* Lighter winds and mainly VFR conditions are expected for this
  weekend, except for patchy FZFG around KTRK each morning. MJD

&&

.AVALANCHE...

Friday's storm will be short duration, but produce a period of
heavy snowfall rates along with strong winds for the Sierra crest.

* Max Snowfall Rates: Up to 2"/hour, mainly between 12 noon and 5
  pm.

* SWE: Between 0.70-1.10" from Yuba Pass southward to Ebbetts
  Pass, dropping off to 0.30-0.70" south of Ebbetts Pass to
  Mammoth Mountain.

* Max Ridge Top Wind Gusts: 80-100 mph mainly between 4 am-4 pm,
  but could continue through 8 pm for Mono County.

&&

.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory from 10 AM to 10 PM PST Friday NVZ002.

     Wind Advisory from 7 AM to 7 PM PST Friday NVZ001-003.

     Lake Wind Advisory from 10 AM to 7 PM PST Friday NVZ004.

CA...Winter Weather Advisory from 7 AM to 10 PM PST Friday CAZ071.

     Winter Weather Advisory from 10 AM to 10 PM PST Friday CAZ072.

     Wind Advisory from 7 AM to 7 PM PST Friday CAZ073.

&&