Alert archive / California / Winter Storm Warnings in 2021

Winter Storm Warning 2, NWS Reno, NV

October 23, 20215 counties in California; Douglas County, Washoe County, Nevada

NWS Reno, NV issued this winter storm warning at Oct 23, 2021, 11:43 AM PDT for 5 counties in California; Douglas County, Washoe County, Nevada. It took effect at Oct 24, 2021, 5:00 PM PDT. It was in force for 28 hr. 10 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Oct 23, 2021, 11:43 AM PDT (18:43 UTC)
In effect from
Oct 24, 2021, 5:00 PM PDT
Expired
Oct 25, 2021, 9:02 PM PDT
In force
28 hr
Issued by
NWS Reno, NV

Counties Alpine County, CA, El Dorado County, CA, Mono County, CA, Nevada County, CA, Placer County, CA, Douglas County, NV, Washoe County, NV

The radar

The Reno radar (KRGX), 92 km from the middle of the area, began a volume at 18:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Oct 25, 6:30 AM PDTHEAVY SNOW 123 Ssw Meyers, CAMEDIA REPORTED 12 INCHES OF HEAVY SNOW ON ECHO SUMMIT.
Oct 25, 7:00 AM PDTSNOW 4.51 Ssw Boca Reservoir, CAOBSERVER REPORTED 4.5 INCHES OF SNOW WITH A 24 HOUR TOTAL OF 4.72 INCHES OF LIQUID PRECIPITATION.
Oct 25, 7:15 AM PDTHEAVY SNOW 52 Sw South Lake Tahoe, CAPOWER OUTAGE IN SOUTH LAKE TAHOE LIKELY DUE TO HEAVY WET SNOW.
Oct 25, 7:30 AM PDTHEAVY SNOW 257 W Truckee, CALAW ENFORCEMENT REPORTED 25 INCHES OF SNOW NEAR SODA SPRINGS SINCE 10 PM LAST NIGHT.
Oct 25, 8:00 AM PDTSNOW 9Tahoe City, CACOOPERATIVE OBSERVER IN TAHOE CITY (AT LAKE LEVEL) REPORTED 24 HOUR TOTAL OF 9.0 INCHES OF SNOW WITH 6.10 INCHES OF LIQUID WATER.
Oct 25, 8:00 AM PDTHEAVY SNOW 104 Nnw Washoe City, NVPUBLIC REPORTS 10 INCHES OF NEW SNOW AT 6200 FEET.
Oct 25, 8:00 AM PDTHEAVY SNOW 121 Nnw Homewood, CATRAINED SPOTTER MEASURED 12 INCHES OF SNOW ALONG WITH 6.4 INCHES OF LIQUID OVER THE LAST 24 HOURS.
Oct 25, 8:00 AM PDTHEAVY SNOW 15Dollar Point, CAPUBLIC REPORTS 15 INCHES OF SNOW ON DOLLAR HILL DR. IN TAHOE CITY.
Oct 25, 8:00 AM PDTSNOW 201 Nw Dollar Point, CATAHOE CITY COOP OBSERVER ESTIMATED 20 INCHES OF SNOW WAS ON THE GROUND AT HIS HOUSE UP NEAR THE HIGH SCHOOL. ELEVATION APPROX 6500 FEET.
Oct 25, 8:20 AM PDTSNOW 181 Ne Incline Village, NVTRAINED SPOTTER IN INCLINE VILLAGE AT 6700 FEET REPORTED 18 INCHES OF SNOW, AND STILL FALLING. HE RECEIVED 5.00 INCHES OF RAINFALL (UNTIL IT STARTED SNOWING) SINCE THURSDAY.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Reno, NV (KREV), launched 12:00Z, 6.7 hours before the alert went out and 166 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Reno, NV at 12:00Z on 2021-10-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Reno, NV at 12:00Z on 2021-10-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1411 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

742 
WWUS45 KREV 231843
WSWREV

URGENT - WINTER WEATHER MESSAGE
National Weather Service Reno NV
1143 AM PDT Sat Oct 23 2021

CAZ072-NVZ002-242300-
/O.UPG.KREV.WS.A.0006.211025T0600Z-211026T0600Z/
/O.NEW.KREV.WS.W.0002.211025T0000Z-211026T0600Z/
Greater Lake Tahoe Area-
1143 AM PDT Sat Oct 23 2021

...WINTER STORM WARNING IN EFFECT FROM 5 PM SUNDAY TO 11 PM PDT
MONDAY ABOVE 7000 FEET...

* WHAT...Heavy wet snow expected above 7000 feet. Total snow
  accumulations of 4-8 inches for Donner Pass and Echo Summit, 3-5
  inches for Spooner Summit, 12-18 inches for Mt Rose Summit, with
  multiple feet of snow for higher mountains. Communities around
  Truckee and the Tahoe Basin are likely to only get an inch or
  two, with mainly rain falling, however there is a 30% chance of
  6 inches of snow if snow levels fall faster than forecast.

* WHERE...Greater Lake Tahoe Area.

* WHEN...From 5 PM Sunday to 11 PM PDT Monday. Heaviest snowfall
  rates of 1-2 inches per hour possible at pass elevations 
  between 8 PM Sunday and 4 AM Monday.

* IMPACTS...Travel could be very difficult. The hazardous 
  conditions could impact the morning or evening commute. Very 
  strong winds could cause extensive tree damage.

* ADDITIONAL DETAILS...Winds will gust to 50 mph across the
  Truckee and Tahoe Basin areas, with ridges gusting well over 100
  mph. This will result in extremely rough water on Lake Tahoe.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid travel if possible, you could be stuck in your vehicle for
many hours. If you must travel, prepare for long delays and carry
an emergency kit with extra food, water and clothing. If you stay
home, have a backup plan in case of power outages.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

CAZ073-242300-
/O.UPG.KREV.WS.A.0006.211025T0000Z-211026T0600Z/
/O.NEW.KREV.WS.W.0002.211025T0000Z-211026T0600Z/
Mono County-
1143 AM PDT Sat Oct 23 2021

...WINTER STORM WARNING IN EFFECT FROM 5 PM SUNDAY TO 11 PM PDT
MONDAY ABOVE 8500 FEET...

* WHAT...Heavy snow expected above 8500 feet. Snow accumulations
  of 3-5 inches in Mammoth Lakes, 3-5 inches along Highway 395 at
  Devils Gate, Conway, and Deadman Summits. Multiple feet of heavy
  wet snow for high elevations including around Tioga and Sonora 
  Passes and Mammoth Mountain.

* WHERE...Mono County.

* WHEN...From 5 PM Sunday to 11 PM PDT Monday. Snowfall rates
  could approach 4 inches per hour in the higher elevation
  mountains after 3 AM Monday.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning or evening 
  commute. Very strong winds could cause extensive tree damage.

* ADDITIONAL DETAILS...Winds will gust 50 to 60 mph across the
  Eastern Sierra, with ridges gusting well over 100 mph. This will
  result in hazardous travel coupled with the snowfall and heavy
  rains.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid travel if possible, you could be stuck in your vehicle for
many hours. If you must travel, prepare for long delays and carry
an emergency kit with extra food, water and clothing. If you stay
home, have a backup plan in case of power outages.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

http://www.weather.gov/reno
4 follow-up statements
225 
WWUS45 KREV 242129
WSWREV

URGENT - WINTER WEATHER MESSAGE
National Weather Service Reno NV
229 PM PDT Sun Oct 24 2021

CAZ072-NVZ002-252130-
/O.CON.KREV.WS.W.0002.211025T0000Z-211026T0600Z/
Greater Lake Tahoe Area-
229 PM PDT Sun Oct 24 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT MONDAY
ABOVE 7000 FEET...

* WHAT...Heavy wet snow expected above 7000 feet. Total snow
  accumulations of 4-8 inches for Donner Pass and Echo Summit, 3-5
  inches for Spooner Summit, 12-18 inches for Mt Rose Summit, 
  with multiple feet of snow for higher mountains. Communities 
  around Truckee and the Tahoe Basin are likely to only get an 
  inch or two, with mainly rain falling; however, there is a 30% 
  chance of 6 inches of snow if snow levels fall faster than 
  forecast.

* WHERE...Greater Lake Tahoe Area.

* WHEN...From 5 PM Sunday to 11 PM PDT Monday. Heaviest snowfall 
  rates of 1-2 inches per hour possible at pass elevations 
  between 8 PM Sunday and 4 AM Monday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the Monday morning commute. Strong winds
  could cause tree damage.

* ADDITIONAL DETAILS...Winds will gust up to 50 mph across the
  Truckee and Tahoe Basin areas with ridges gusting well over 100
  mph. This will result in extremely rough water on Lake Tahoe.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid travel if possible, you could be stuck in your vehicle for
many hours. If you must travel, prepare for long delays and carry
an emergency kit with extra food, water and clothing. If you stay
home, have a backup plan in case of power outages.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

CAZ073-252130-
/O.CON.KREV.WS.W.0002.211025T0000Z-211026T0600Z/
Mono County-
229 PM PDT Sun Oct 24 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT MONDAY
ABOVE 8500 FEET...

* WHAT...Heavy snow expected above 8500 feet. Snow accumulations 
  of 3-5 inches in Mammoth Lakes, 3-5 inches along Highway 395 
  at Devils Gate, Conway, and Deadman Summits. Multiple feet of 
  heavy wet snow for high elevations including around Tioga and 
  Sonora passes and for Mammoth Mountain.

* WHERE...Mono County.

* WHEN...From 5 PM Sunday to 11 PM PDT Monday. Snowfall rates 
  could approach 4 inches per hour in the higher elevation 
  mountains after 3 AM Monday.

* IMPACTS...Travel could be very difficult to impossible. The
  hazardous conditions could impact the Monday morning commute. 
  Very strong winds could cause extensive tree damage.

* ADDITIONAL DETAILS...Winds will gust 50 to 60 mph across the
  Eastern Sierra with ridges gusting well over 100 mph. This will
  result in hazardous travel coupled with the snowfall and heavy 
  rains.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid travel if possible, you could be stuck in your vehicle for
many hours. If you must travel, prepare for long delays and carry
an emergency kit with extra food, water and clothing. If you stay
home, have a backup plan in case of power outages.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

http://www.weather.gov/reno
124 
WWUS45 KREV 251025
WSWREV

URGENT - WINTER WEATHER MESSAGE
National Weather Service Reno NV
325 AM PDT Mon Oct 25 2021

CAZ072-NVZ002-260600-
/O.CON.KREV.WS.W.0002.000000T0000Z-211026T0600Z/
Greater Lake Tahoe Area-
Including the cities of South Lake Tahoe, Truckee, Stateline, 
and Incline Village
325 AM PDT Mon Oct 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING...

* WHAT...Heavy snow expected with snow levels low enough this 
  morning for a period of heavy wet snow to occur down to lake 
  level. Total snow accumulations of 4-9 inches at lake level 
  mainly this morning, 12-18 inches for Spooner Summit, 18-24 
  inches for Mt Rose Summit, with several feet or more on higher 
  peaks. The snow will possibly mix with or change back over to 
  rain at times in the afternoon at lake level. So the worst 
  conditions for lake level will be through the morning.
  
* WHERE...Greater Lake Tahoe Area.

* WHEN...From 5 PM Sunday to 11 PM PDT Monday. Heaviest snowfall
  rates of 2-3 inches per hour this morning.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions will impact the morning commute for all elevations
  and mainly across the passes later this afternoon. 

* ADDITIONAL DETAILS...Winds will gust up to 80 mph across the
  ridges with white out conditions at times this morning for area
  passes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid travel if possible, you could be stuck in your vehicle for
many hours. If you must travel, prepare for long delays and carry
an emergency kit with extra food, water and clothing. If you stay
home, have a backup plan in case of power outages.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

CAZ073-260600-
/O.CON.KREV.WS.W.0002.000000T0000Z-211026T0600Z/
Mono County-
325 AM PDT Mon Oct 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING ABOVE 8500 FEET...

* WHAT...Heavy snow expected above 8500 feet. Snow accumulations 
  of 3-5 inches in Mammoth Lakes, 3-5 inches along Highway 395 
  at Devils Gate, Conway, and Deadman Summits. Multiple feet of 
  heavy wet snow for high elevations including around Tioga and 
  Sonora passes and for Mammoth Mountain.

* WHERE...Mono County.

* WHEN...From 5 PM Sunday to 11 PM PDT Monday. Snowfall rates
  could approach 4 inches per hour in the higher elevation
  mountains.

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the Monday morning commute. 
  Very strong winds could cause extensive tree damage.

* ADDITIONAL DETAILS...Winds will gust 50 to 60 mph across the 
  Eastern Sierra with ridges gusting well over 100 mph. This 
  will result in hazardous travel coupled with the snowfall and 
  heavy rains.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid travel if possible, you could be stuck in your vehicle for
many hours. If you must travel, prepare for long delays and carry
an emergency kit with extra food, water and clothing. If you stay
home, have a backup plan in case of power outages.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

http://www.weather.gov/reno
167 
WWUS45 KREV 252034
WSWREV

URGENT - WINTER WEATHER MESSAGE
National Weather Service Reno NV
134 PM PDT Mon Oct 25 2021

CAZ072-NVZ002-260600-
/O.CON.KREV.WS.W.0002.000000T0000Z-211026T0600Z/
Greater Lake Tahoe Area-
Including the cities of South Lake Tahoe, Truckee, Stateline, 
and Incline Village
134 PM PDT Mon Oct 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING...

* WHAT...Snow. Expect snow showers to continue along the Sierra
  Crest into this evening. Additional snow accumulations of up to
  two inches are possible.

* WHERE...Greater Lake Tahoe Area.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Plan on slippery road conditions through tonight with
  wet roads refreezing. 

* ADDITIONAL DETAILS...Fog may develop in some locations around
  the Tahoe Basin and along Interstate 80 near Truckee tonight.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, prepare for long delays and carry an 
emergency kit with extra food, water and clothing. If you stay 
home, have a backup plan in case of power outages.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

CAZ073-260600-
/O.CON.KREV.WS.W.0002.000000T0000Z-211026T0600Z/
Mono County-
134 PM PDT Mon Oct 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS
EVENING...

* WHAT...Snow. Additional snow accumulations of 4 to 8 inches
  above 7500 feet and zero to 4 inches below 7500 feet. Winds
  gusting as high as 40 mph.

* WHERE...Mono County.

* WHEN...Until 11 PM PDT this evening.

* IMPACTS...Plan on slippery road conditions through tonight
  tonight with wet roads refreezing. 

* ADDITIONAL DETAILS...Fog may develop in some eastern Sierra
  valleys if skies clear and wind turn calm tonight.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, prepare for long delays and carry an 
emergency kit with extra food, water and clothing. If you stay 
home, have a backup plan in case of power outages.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

http://www.weather.gov/reno
069 
WWUS45 KREV 260402
WSWREV

URGENT - WINTER WEATHER MESSAGE
National Weather Service Reno NV
902 PM PDT Mon Oct 25 2021

CAZ072-073-NVZ002-260515-
/O.CAN.KREV.WS.W.0002.000000T0000Z-211026T0600Z/
Greater Lake Tahoe Area-Mono County-
902 PM PDT Mon Oct 25 2021

...WINTER STORM WARNING IS CANCELLED...

Heavy snowfall has ended and the Winter Storm Warning has been
cancelled. A few lingering spotty snow showers will be possible 
this evening. Use caution on the roadways tonight as ample
moisture and colder temperatures could lead to slick and icy 
spots. 

$$

http://www.weather.gov/reno

The office that day

Everything else NWS Reno, NV issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 23, 11:27 AM PDTHigh Wind WarningREVMono40 hr
Oct 23, 11:27 AM PDTWind AdvisoryREVChurchill, Lyon, Pershing, Washoe27 hr

Nearby

Winter Storm Warnings in California, 2021Winter Storm Warnings in Nevada, 2021Every winter storm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.