A stronger winter storm produced several waves of new snow and high winds that impacted the region during the third week of January. A relatively long-duration atmospheric river from 9-11 January supported forcing and moisture for the first in the series of winter systems that brought heavy Sierra snowfall with accumulations ranging from 3-6 feet across the Sierra Crest.
Every event with a place to put it; 3 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.
A stronger winter storm produced several waves of new snow and high winds that impacted the region during the third week of January. A relatively long-duration atmospheric river from 9-11 January supported forcing and moisture for the first in the series of winter systems that brought heavy Sierra snowfall with accumulations ranging from 3-6 feet across the Sierra Crest. The heaviest snowfall occurred in Mono County over the 3-day period with heavy, unrelenting snowfall that forced a prolonged closure of US-395 from Bridgeport to Bishop from late morning January 9th through the afternoon January 11th. On January 9th, heavy rain across the Lake Tahoe Basin changed to heavy snow below 7000 ft, leading to snowfall totals ranging from 8-20 inches through January 11th. Over 2 feet of snowfall was observed in parts of northeast California above 5000 feet. On January 9th mostly rain fell across western Nevada with storm total precipitation amounts ranging between 0.75-2 inches across much of Douglas, Carson City, southern Washoe, Mineral, and Lyon counties. The heavier rainfall across those contributed to a major rockfall and subsequently lead to an extended road closure on SR-208 in Wilson Canyon (Figure 4). Reports of areal flooding included I-80 near Lockwood, NN, Geiger Grade at Toll Rd in the Virginia City highlands, and along US-395 south of Reno with flooding from Steamboat Creek spilling over Towne Road. The changeover to snow in western Nevada arrived during the morning commute on January 10th which led to several related traffic incidents that included a 19-car pile-up on the Galena Bridge on I-580.
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 Jan 9, 5:10 AM PST, 2 hours 50 minutes earlier.
Area Forecast Discussion
National Weather Service Reno NV
510 AM PST Mon Jan 9 2023
.UPDATE...
Snow accumulations will be possible down to valley floors of
western Nevada Tuesday as a colder system moves into the region.
Therefore, the Winter Storm Watches for western Nevada were
upgraded to Winter Weather Advisories, which are in effect from 2
AM to 4 PM Tuesday.
&&
.PREVIOUS DISCUSSION... /issued 340 AM PST Mon Jan 9 2023/
SYNOPSIS...
A strong atmospheric river making landfall this morning will bring
heavy Sierra snow, strong winds, and a mixture of heavy wet snow and
lower elevation flood concerns today through Tuesday. Snow levels
will vary widely Monday so the primary impacts will be winter
travel in the Sierra and minor urban and small creek flooding
risks in the lower elevations. A short storm break is possible
mid-late week but more storms appear likely next weekend and
beyond.
DISCUSSION...
STRONG ATMOSPHERIC RIVER (TODAY - TUESDAY PM):
TODAY:
* SUMMARY: The initial part of the storm is currently moving into
the region as of this writing. We will likely see variable
waves of precipitation and moisture throughout the day, with a
short break in activity for a portion of this evening and early
night, with a heavier precipitation round Tuesday morning.
* VARIABLE SNOW LEVELS: Current observations along the valley
floors of far western Nevada show warm air currently in place
with south-southeasterly winds. Light rain is ongoing, which is
mixing moisture down to the surface, causing dewpoints to rise
from out of the mid-upper 20s. High-resolution model soundings
show valley floor temperatures and dewpoints bouncing between 34
to 39 degrees this morning through 7:00 AM PST. This will limit
the potential for snow down to valley floors this morning. We'll
likely see rain or a rain-snow mix. However, above 5000 feet,
we could see a dusting to an inch as temperatures and dewpoints
hover around 32 to 34 degrees. Some spotty freezing rain will
also be possible in warmer pockets of air. By 10:00 AM PST, snow
levels rise to around 7000 feet, bringing rain to western
Nevada. Snow levels then slowly drop to 4500 to 5000 feet late
this afternoon into this evening in far western, bringing some
light snowfall accumulations to areas above 5000 feet by 7:00 PM
PST. Lower snow levels are possible over the Basin and Range
into the evening, so we could see a brief moment of snow late
this afternoon. A break will occur tonight, until the next wave
of moisture enters western Nevada early Tuesday morning. More on
this in the next section.
* SIERRA SNOW: Variable snow levels this morning continue to bring
headaches to the forecast. Snow began moving into the higher
Sierra around 10:00 PM PST yesterday evening. Drier air within
Sierra valleys is currently having an effect on snow levels.
Snow levels as of this writing are hovering around 6000 feet,
with cameras along I-80 over Donner Summit showing moderate
snowfall. Deterministic models and the NBM show snow levels
bouncing between 5500 to 7000 feet before 10:00 AM PST. There
remains a high boom/bust potential due to these widely variable
snow levels through the day. We'll likely see moderate-to-heavy
snowfall rates above 6500-7000 feet, with accumulations of 6 to
18" possible through this evening, with locally higher amounts
to 2 feet above 7000 feet. Below 6500 feet, we'll likely see 2
to 6" of snow. Dangerous travel conditions are expected all day
across the Sierra. So delay your travel if you can.
* URBAN AND SMALL STREAM FLOODING/MAINSTEM RIVER RISES: With
model snow levels looking to be lower than were previously
forecast, flooding potential could be mitigated partially.
Urban, small stream, and mainstem river rises are still likely,
especially with rain falling below about 6500 to 5000 feet.
* WINDS: Sierra ridge gusts are increasing this morning. We'll see
a peak gust potential of 130 to 150 mph until mid-morning. For
lower elevations, the heavier precipitation will hinder some of
the wind potential. However, gusts 50+ mph are possible in
Surprise Valley- far northeast California-northwest Nevada and
Mineral/southern Lyon-Churchill counties where more lulls in
precipitation are likely due to dry air entrainment. After
seeing wind prone areas along US-95 peak out around 80 mph
Saturday night, it is possible that areas near Walker Lake could
see short burst of 70+ mph gusts today.
TONIGHT - TUESDAY PM:
* SUMMARY: We'll see a short break between shortwaves tonight
from around 8:00 PM to 12:00 AM PST Tuesday. Another wave of
moisture will then enter the region early Tuesday morning
bringing a myriad of impacts to the region through Tuesday
evening/night.
* SNOW DOWN TO VALLEY FLOORS: Snow will affect the lower valley
floors of western Nevada through the early afternoon Tuesday,
with 1 to 3" possible on valley floors, and 3 to 6" possible
above 5000 feet. In the Sierra, we'll see continuous snowfall
through the day and part of the evening, bringing 6 to 12" to
areas west of US-395 in northeast California, 12 to 24" above
7000 feet and 6 to 12" less than 7000 feet in the Sierra.
* MAINSTEM RIVER RISES: The most recent CNRFC forecast (9:00 AM
PST Saturday) shows mainstem rivers such as the Susan, Feather,
Truckee, and Carson coming up late Tuesday night. We'll see
appreciable rises, but likely most rivers will not hit monitor
or flood stage. The next CNRFC forecast is slated for 9:00 AM
PST this morning, so we'll get a better idea of flooding
potential then.
* WINDS: Ridge winds are expected to increase Tuesday morning and
gust up to 80+ mph, while lower elevations could see increased
breezes to 30 mph, especially during lulls in precipitation. -
ANOTHER WEAK WAVE WEDNESDAY:
* Another shortwave trough will bring chances for light snow to
the Sierra (0.5 to 3"), with slightly heavier accumulations
possible along the higher terrain near the Sierra Buttes and
Lassen National Park (1 to 4") Wednesday. After that, we'll see
a weak ridge build in over the Great Basin bringing mainly dry
and quiet conditions to the region. Ensemble models do hint at
a moderate storm affecting the Sierra and western Nevada
Saturday through Sunday, but it is low confidence. Looking
ahead, there are still signals for storms to affect the West
Coast through the end of January.
-Johnston
AVIATION...
* A strong storm will move through the Sierra and western NV tonight
through Tuesday with strong upper level winds likely to bring
turbulence, LLWS and periods of heavy precipitation. Our airports
continue to be in that zone of uncertainty when it comes to snow
levels, especially between 4500-6500 feet MSL, as snow levels will
be highly variable at times. Right now, we are looking at some
snow early on Monday before the warmest and heaviest precipitation
arrives late in the morning into the afternoon. Snow levels then
will generally favor valley floors as we head into Monday night
and Tuesday.
* WINDS: Ridge level winds will remain strong through the event, but
a couple of periods stand out, 08Z-20Z Monday and 09Z-20Z Tuesday.
FL100 winds increase to 60-70 kts during these times with ridge
level gusts approaching or possibly exceeding 115 kts. The
probability for widespread moderate turbulence with occasional
bouts of severe turbulence increase dramatically for these periods
in addition to LLWS/rotors and strong surface south to southwest
wind gusts in excess of 40 kts along the eastern Sierra. For
tonight and Monday morning, these more extreme conditions will be
possible along the entire east side from KSVE-KMMH with the focus
shifting to KCXP-KMMH late Monday night into Tuesday morning.
* PRECIPITATION: At some point, all airports will likely see
accumulating snow. Given the uncertainty in snow levels,
especially Monday, snow amounts could vary considerably, even at
Tahoe level sites where periods of rain are possible during the
warm part of the storm Monday. Latest indications show things
starting as snow early Monday morning (06-12Z) then a change over
to rain or a rain-snow mix below 5500-6500 feet MSL late morning
to mid afternoon Monday, then falling to valley floors by Monday
evening and continuing into Tuesday. Latest projections indicate
total accumulations of 1-2 feet at Sierra terminals with 2-6
inches for KRNO-KCXP-KMEV (most falling Monday night into Tuesday
morning for the lower elevation sites). Bottom line: be prepared
for snow accumulations during the entire storm and be ready for
adjustments to amounts as conditions unfold. Between the wind and
the heavy precipitation, flying is going to be a rough venture
late tonight through Tuesday!
* A few light snow showers are possible Wednesday-Wednesday night as
a weak system moves through northern CA. Otherwise, there will be
an overall break from the intense atmospheric river systems.
Another storm is possible the weekend of the 14-15th with the
track favoring a trajectory more toward southern CA-NV-AZ, but
quickly followed by a colder storm early next week. More on this
later.
Johnston/Hohmann
&&
.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory from 2 AM to 4 PM PST Tuesday NVZ005.
Winter Storm Warning until 4 AM PST Wednesday NVZ002.
Winter Weather Advisory from 2 AM to 4 PM PST Tuesday NVZ001.
Winter Weather Advisory from 2 AM to 4 PM PST Tuesday NVZ003.
CA...Winter Weather Advisory from 2 AM to 4 PM PST Tuesday CAZ070.
Winter Storm Warning until 4 AM PST Wednesday CAZ071.
Winter Storm Warning until 4 AM PST Wednesday CAZ072.
Winter Storm Warning until 4 AM PST Wednesday CAZ073.
&&The national radar mosaic for the moment the first event began.
3 heavy rain, 2 heavy snow, 1 high wind, 1 debris flow. Local standard time, as filed.
COCORAHS stations located 1.7 mi E of Sparks, NV (NV-WH-31), and 1.7 mi WSW of Reno, NV (NV-WH-133), reported a 24 hour rainfall amounts of 0.97 and 0.99 inches respectively.
COCORAHS station located 0.9 mi ESE of the Diamond Peak Ski Base (NV-WH-121) reported a 24 hour rainfall amount of 1.66 inches.
An ASOS located at the Reno-Tahoe International airport and an official NWS observation located 2.0 SSW of Sun Valley, NV, reported a 24 hour rainfall amounts of 1.00 and 1.07 inches respectively.
A trained spotter located 1.0 mi NNW of Incline Village reported a 24 hour snowfall total of 15.5 inches (SWE: 1.59 inches), as well as 3 day storm total snowfall amount of 27.5 inches.
The public at the Mount Rose Ski Base and Diamond Peak Ski Base reported 24 hour snowfall totals of 12 and 22 inches respectively, as well as 3 day storm total snowfall amounts of 56 and 31 inches respectively.
Mesonet Station (NV DOT-REV) located along US-95 near Walker Lake, NV reported a peak wind gust from the south at 75 mph at 11:57 AM.
A massive landslide on State Route 208 through Wilson Canyon forced the closure of the highway for an indeterminate amount of time. The Nevada Department of Transportation (NDOT) says the rockslide was likely caused by the recent heavy precipitation. The debris fell across roughly 400 feet of roadway around 6:00 PM Tuesday night, NDOT estimates.
There were no immediate indications of any injuries due to the landslide.
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: 1080875, 1080878, 1080879, 1080871, 1080872, 1086429, 1086435.