Another winter storm enters the region with a second round of snow and strong winds across Sierra ridges. Travel and commute impacts related to not only heavy snow but also accompanying strong winds causing areas of blowing snow.
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.
Another winter storm enters the region with a second round of snow and strong winds across Sierra ridges. Travel and commute impacts related to not only heavy snow but also accompanying strong winds causing areas of blowing snow.
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 15, 3:33 AM PST, 5 hours 27 minutes earlier.
Area Forecast Discussion
National Weather Service Reno NV
333 AM PST Wed Dec 15 2021
.SYNOPSIS...
Another winter storm will bring moderate to heavy snowfall with
windy conditions this afternoon through Thursday morning. Whiteout
conditions are possible in the Sierra. We should see a break from
significant storms Friday through Sunday, but a weak system is
possible later this weekend. An active storm pattern is likely for
next week. Plan on delays and impacts for holiday travel.
&&
.SHORT TERM...
While all winter warnings and advisories will remain intact, this
storm system looks more potent and we will trend snow totals
upward by a few inches in the headlined areas. We will continue
highlighting the gusty winds with blowing snow and whiteout
conditions again for the Sierra, with travel conditions at times
potentially even worse compared to the previous storm.
Here are the highlights for our next winter storm, which arrives
by midday-early afternoon for northeast CA-northern Sierra crest
and spreads rapidly across the remainder of eastern CA-western NV
from late afternoon through tonight. Expect another round of
difficult travel and plan extra time for the commutes this
evening and Thursday morning, which could continue into Thursday
evening as cold conditions lead to icy roads after the snow ends.
WINDS:
S-SW winds will increase along ridgelines through today, mixing
down into the lower elevations this afternoon and evening. Based
on HREF guidance, the strongest winds are expected this evening
and overnight. Wind gusts of 40-50 mph are likely across the
eastern Sierra and far western NV, while Sierra crest ridge gusts
could peak in the 100-120 mph range. Short bursts of gusts over
60 mph may impact some of the wind prone sites along US-395 and
I-580.
SNOW LEVELS:
Once again snow levels will be tricky for lower valleys. While
there is plenty of cold air in place for all elevations, these
aforementioned S-SW winds will bring some warming to the region,
Snow levels could rise above some valley floors in far western NV,
although the same guidance holds temperatures near or below
freezing through tonight. While a rain-snow mix is possible at
times, the latest trend seems to indicate more snow than rain for
the advisory area of northwest-far western NV and northeast CA.
Therefore we will nudge snowfall totals up a bit but still within
advisory values. Regardless of the precip type, expect messy
travel conditions this afternoon through Thursday night with all
hazards from wet/slush to snow and ice on most roads.
SNOW TOTALS:
This incoming storm doesn't have quite the moisture tap compared
to the previous monster storm, but is still respectable and
actually looks a little more robust with the most recent guidance.
We will trend snow amounts up a few inches for the Sierra zones
and increase lower elevation amounts by an inch or two, with
details included in an upcoming update of the warning and
advisory statement. Even outside the advisory areas in west
central NV, amounts from a dusting up to 2" could produce
hazardous slick conditions as the potential mixing of winds
mentioned in the previous segment is less likely to push
temperatures above freezing in those valleys along US-95 and
US-50. The highest snowfall rates will be from around sunset
today through daybreak Thursday, with the added hazard of blowing
snow due to the expected gusty winds.
BEYOND THIS SYSTEM:
The snow will taper to showers Thursday afternoon before ending,
but tricky travel will continue Thursday night and Friday, with
very cold temperatures leading to freezing of road surfaces again
each night into the start of the weekend. Valley inversions
reinforced by the expanding snow cover will keep daytime
temperatures near or below the mid 30s Friday even with some sun
returning. MJD
.LONG TERM...Saturday through next week...
Early Saturday will be quiet, with winds increasing into the
afternoon as another short-wave trough brushes by the region. Light
snow showers are possible, especially in northeast California and
the upper elevations of the Sierra late Saturday afternoon through
Sunday. These showers could cause travel impacts over the northern
Sierra and upper elevations of Lassen-Plumas counties.
Turning our attention to early next week, ensembles are in very
strong agreement in a long-wave trough digging off the West Coast.
This will open the storm door for our region, with waves of moisture
impacting the Sierra through midweek. To be determined on how
large, but there is a good shot at additional mountain and
foothill snow with valley precipitation type to be determined.
Signals point towards this progressive pattern continuing through
late next week, which would affect Christmas travel.
-Johnston
&&
.AVIATION...
The next winter storm arrives today, with impacts expected late this
morning through Thursday afternoon.
This morning:
* High-level clouds are moving over the Sierra early this morning.
These high clouds are restricting the formation of FZFG at TRK and
TVL. TRK has some very shallow FZFG near the observing station,
but the terminal and runways are not affected by this. TVL has not
had any formation of FZFG this morning. 12Z TAFs will reflect this
change.
This afternoon into Thursday:
Snow:
* Snow showers will begin in northeast California (SVE) between 16-
18z, 18-20z in the northern Sierra (TRK-TVL), and 01-04z in the
Eastern Sierra (MMH). Snowfall rates look significant again, with
1-2" per hour rates possible tonight into Thursday morning and an
80+% chance of runway accumulations. IFR/LIFR conditions, mountain
obscurations, and an increased supercooled liquid drop threat (in-
flight icing) are all probable during this storm.
* Precipitation types within the lower valleys of western Nevada
(RNO-CXP-MEV-NFL) could be problematic during this storm as snow
levels waver during this evening. High-resolution guidance from
the HRRR, NAM 3 km, and WRF-ARW/FV3 are showing periods of rain
mixing in with snow below 5000 feet. Chances for runway
accumulations are higher than the previous forecast, with 70-90%
chance of at least a dusting, 50-70% of a least 1", and 20-50%
chance of at least 2". Chances of greater than 4" at RNO-CXP-MEV
are 10-40%.
Winds:
* Wind shear and turbulence are expected with periods of south to
west surface winds to 40 kts at all regional terminals. Strong
winds will likely persist into this evening-Thursday morning
timeframe.
Icing:
* Icing impacts to aviation will be elevated across the Sierra and
into western Nevada this afternoon through Thursday morning. Be
sure to check forecast icing conditions and PIREPs at
aviationweather.gov before departing or arriving at area
terminals.
-Johnston
&&
.REV Watches/Warnings/Advisories...
NV...Winter Storm Warning from 1 PM this afternoon to 10 AM PST
Thursday NVZ002.
Winter Weather Advisory from 1 PM this afternoon to 10 AM PST
Thursday NVZ005.
Winter Weather Advisory from 4 PM this afternoon to 10 AM PST
Thursday NVZ003.
CA...Winter Storm Warning from 1 PM this afternoon to 10 AM PST
Thursday CAZ072.
Winter Weather Advisory from 1 PM this afternoon to 10 AM PST
Thursday CAZ070-071.
Winter Weather Advisory from 7 PM this evening to 1 PM PST
Thursday CAZ073.
&&
For more information from the National Weather Service visit...
http://weather.gov/renoPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
839 AM PST WED DEC 15 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 AM HEAVY SNOW JUNE MOUNTAIN SKI BASE 37.76N 119.09W
12/15/2021 M44.0 INCH MONO CA PUBLIC
STORM TOTAL SNOWFALL ENDING YESTERDAY.
0700 AM HEAVY SNOW 1 SW TOMS PLACE 37.55N 118.71W
12/15/2021 M16.0 INCH MONO CA TRAINED SPOTTER
SNOWFALL IN PAST 24 HOURS. STORM TOTAL OF 27
INCHES.
0600 AM SNOW MT. ROSE SKI BASE 39.32N 119.89W
12/15/2021 M12.0 INCH WASHOE NV PUBLIC
12 TO 14 INCHES IN THE PAST 24 HOURS. STORM
TOTAL OF 78 TO 86 INCHES.
0625 AM SNOW MAMMOTH MOUNTAIN SKI BA 37.65N 119.04W
12/15/2021 M12.0 INCH MONO CA PUBLIC
11 TO 13 INCHES OF SNOWFALL IN PAST 24
HOURS. STORM TOTAL SNOWFALL OF 44 TO 53
INCHES FROM 9000 FEET TO 11000 FEET,
RESPECTIVELY.
0645 AM SNOW HEAVENLY SKI BASE 38.93N 119.93W
12/15/2021 M9.0 INCH EL DORADO CA PUBLIC
STORM TOTAL OF 59 INCHES.
0630 AM SNOW PALISADES TAHOE SKI 39.19N 120.24W
12/15/2021 M8.0 INCH PLACER CA PUBLIC
4 TO 8 INCHES OF SNOWFALL IN PAST 24 HOURS.
STORM TOTAL OF 33 TO 58 INCHES AT 6463 FEET
AND 8000 FEET, RESPECTIVELY.
0550 AM SNOW 1 SSW NORTHSTAR SKI 39.26N 120.13W
12/15/2021 U6.0 INCH PLACER CA PUBLIC
SNOWFALL IN PAST 24 HOURS. STORM TOTAL OF 50
INCHES.
0700 AM SNOW 2 N TRUCKEE 39.35N 120.20W
12/15/2021 M2.1 INCH NEVADA CA COCORAHS
SNOWFALL IN PAST 24 HOURS. STORM TOTAL OF
21.1 INCHES.
0630 AM SNOW HOMEWOOD MOUNTAIN SKI 39.09N 120.16W
12/15/2021 M2.0 INCH PLACER CA PUBLIC
1-2 INCHES IN PAST 24 HOURS. STORM TOTAL OF
31 TO 47 INCHES FROM 6432 FEET TO 8000 FEET,
RESPECTIVELY.
&&The national radar mosaic for the moment the first event began.
1 avalanche, 1 heavy snow. Local standard time, as filed.
Trained spotters and the public reported heavy snowfall amounts up 12 at Diamond Peak Ski Base, 14 at 1.0mi NNW of Incline Village, and 24 at the MT. Rose Ski Base.
NDOT employee reported a moderate snowfall ranging 2-4 over the Montgomery Pass along US 6.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2021Every state in 2021This day in weather historyWarnings in Nevada, December 2021
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: 992608, 991417.