The strongest winter storm of December finished up early on New Year's day. This atmospheric river (AR) enhanced winter storm initially produced very high snow levels near 9000 feet on 30 December with heavy rainfall continuing below that elevation.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS REV wrote it up.
The strongest winter storm of December finished up early on New Year's day. This atmospheric river (AR) enhanced winter storm initially produced very high snow levels near 9000 feet on 30 December with heavy rainfall continuing below that elevation. But colder air and enhanced forcing, coupled with the final push of extensive moisture worked in unison to rapidly drop snow levels to most valley floors (above 4000 feet) during the morning of New Year’s Eve that carried over into the overnight hours through early morning New Year’s day. Some foothill areas received 1-2 feet plus of new snow with Sierra snowfall totals generally ranging from 18-30 inches below 7000 feet. Higher Sierra areas and passes received 3-4 feet plus of accumulating snow above 7000 feet before the winter system exited the region.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Reno, NV wrote its last area forecast discussion before the first event at Dec 31, 2:08 PM PST, 9 hours 53 minutes earlier.
Area Forecast Discussion
National Weather Service Reno NV
208 PM PST Sat Dec 31 2022
.SYNOPSIS...
Snow will continue to bring hazardous driving conditions through
tonight with slick roads into New Year's Day morning. The active
weather pattern is going to continue through the first week to 10
days of the New Year with storms lined up, starting with a weaker
system late Monday into early Tuesday followed by a bigger storm
Wednesday through early Friday. If you have travel plans over the
next couple of weeks, prepare for winter weather and stay
attentive to the latest forecasts.
&&
.SHORT TERM (Through Sunday evening)...
Snow levels have tumbled across the Eastern Sierra into western
Tahoe, and current observations are reflecting the changeover from
rain to snow. Temperatures across the region are agreeing,
supporting the snow levels rapidly falling. Reports of travel
troubles are showing up this afternoon on I-80, around Lake Tahoe
and northern Nevada. Radar depicts an intense swath of
precipitation along and north of I-80, which high resolution model
guidance suggests will continue to drape south along the Sierra
and western NV through tonight.
This translates to periods of heavy snow persisting through the
evening. Valleys could accumulate 3-8+" of fresh, heavy, wet snow
before this system exits this evening. Elevations above 5000' will
see higher totals, on the order of 12+", possibly higher where
stronger and persistent snow bands occur. Travel will continue to
be impacted through the evening and overnight, and will likely
still be troublesome by sunrise. The snow on roads will allow
slushy conditions that could freeze through the overnight, so
slick conditions are expected into New Year's Day morning.
Clearing skies will allow temperatures to fall well below
freezing, with valleys dipping into the 20s while Sierra and Lake
Tahoe locations find the mid teens.
HRICH
The earlier than anticipated transition to snow has helped slow the
hydrologic response and avoid more significant flooding impacts.
Mainstem river flooding is currently only ongoing along the East
Fork of the Carson River near Gardnerville. Along other rivers
and reaches, high flows will take some time to move through the
system, but additional flooding is not expected. As of early
afternoon Saturday, a few streams in the Tahoe Basin have yet to
crest and other streams in the region remain very high. It will
take until this evening or early New Year's Day for high flows to
fully recede - longer for our main stem rivers and larger
streams.
-TB
.LONG TERM (Monday Onward)...
* The next week to 10 days will remain active as latest cluster
analysis holds on to negative height anomalies near the west
coast and strong trans-Pacific flow persists at our latitude.
Several larger storms interspersed with weaker waves and warm
advection will keep things rather gray and wet with plenty of
moisture to work with based on the latest GEFS/EPS IVT
probabilities. Timing of the first couple of waves this week are
fairly agreed upon with some nuances, but after Friday,
confidence in timing and character of incoming storms is quite a
bit lower.
* Monday PM-Tuesday AM Storm: This is a fast moving and colder
system. While it has a weak moisture tap, the open nature of
this wave as it moves quickly through CA-NV will limit residence
time for any prolonged period of precipitation to develop.
Latest WPC guidance indicates total QPF 0.50-0.75" along the
crest, around 0.25" in the Tahoe Basin and eastern Sierra
through Mono County, and amounts tapering to 0.10" or less
elsewhere. Snow levels will be down to all valley floors, so an
additional 4 to 8" of snow area expected for the Sierra
communities with up to a an inch or two possible for western NV
valleys. This could impact the Monday evening and Tuesday
morning commutes. Some medium range models show a weak shortwave
on the heels of this one for Tuesday night, but confidence is
low on this feature and blended ensemble guidance keeps some
light QPF along and to the west of the crest.
* Wednesday PM-Friday AM Storm: This will be our next bigger storm
as it is more developed (less open) and has a decent PWAT tap
like our current storm. Some solutions show a more elongated
trough initially which would bring more southerly flow and keep
heaviest precipitation on the west side of the Sierra until
frontal passage late Wednesday night or Thursday morning.
However, this detail is still to be worked out given the storm
is still a number of days out. It appears to be a colder system
overall, but snow levels could rise as high as 6000-7000' at
some point prior to frontal passage. Latest WPC guidance is a
bit drier than the blended guidance, especially to the lee of
the Sierra. Even so, current projections show another 3-5" of
water along the crest, 2-3" in the Tahoe Basin and 0.25-0.75" in
western NV. That's several more feet or more of snow for the
high Sierra and some accumulating snow possible even down to
lower valley floors. Breezy conditions will precede the
precipitation, especially the ridges/backcountry, as 700 MB
winds increase to 45-50 kts.
* Another wet storm is possible next weekend with more variability
in timing and track. A number of scenarios bring a major storm
into the Sierra and western NV while others bring a few weaker
systems through the region and then a bigger one early the
following week.
Hohmann
&&
.AVIATION...
* Moderate to heavy snow will continue through 02-06Z for the
Tahoe and western NV terminals and through 09Z for KMMH along
the eastern Sierra with widespread IFR/LIFR conditions.
Conditions should slowly improve from north to south overnight,
although low clouds and light snow may persist into New Year's
Day morning for the eastern Sierra KMEV-KMMH.
* Generally VFR conditions Sunday-Monday AM with light winds. The
next storm is a weaker storm but will be capable of light snow
at all elevations late Monday into early Tuesday morning. This
will be followed by a more substantial storm Wednesday PM to
Friday AM.
Hohmann
&&
.REV Watches/Warnings/Advisories...
NV...Winter Storm Warning until 4 AM PST Sunday NVZ002.
Winter Storm Warning until 4 AM PST Sunday NVZ001-004.
Winter Storm Warning until 4 AM PST Sunday NVZ003.
Winter Weather Advisory until 10 PM PST this evening NVZ005.
CA...Winter Storm Warning until 4 AM PST Sunday above 5000 feet for
CAZ071.
Winter Storm Warning until 4 AM PST Sunday CAZ072.
Winter Storm Warning until 4 AM PST Sunday CAZ073.
&&The national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
The public at the Mount Rose Ski Base and Diamond Peak Ski Base both reported Storm total snowfall of 40 inches during the period from 12/31/22 through 1/1/23.
A CO-OP observer (DAGN2) located at Dagget Pass, NV, as well as the public (via social media) located 2.0 miles SE of Gardnerville, NV, and 10.0 mi E of Gardnerville Ranch reported storm total snowfall of 31, 30, and 25 inches respectively during the period from 12/31/22 through 1/1/23.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2023Every state in 2023This day in weather historyWarnings in Nevada, January 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1078731, 1078786.