Heavy Snow and High Wind in California, December 9 to 11, 2015

Name: Heavy Snow and High Wind in California, December 9 to 11, 2015
Start: 2015-12-09T06:00
End: 2015-12-11T18:00
Location: California

December 9 to 11, 2015 · NWS STO · 5 events in 4 counties and zones

A cold storm from the Gulf of Alaska merged with subtropical moisture to bring heavy snow to the mountains and gusty winds. There were snowfall amounts of 1 to 2 feet above 6000 ft, with measurable snow down to as low as 3200 feet.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 1
Injuries: 0
Property damage: $25,000
Crop damage: None recorded
Events: 5

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.

What happened

The episode as NWS STO wrote it up.

What forecasters said that day

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 Sacramento, CA wrote its last area forecast discussion before the first event at Dec 9, 2:32 AM PST, 3 hours 28 minutes earlier.

Area forecast discussion, Dec 9, 2:32 AM PST, 3 hours 28 minutes before

Area Forecast Discussion
National Weather Service Sacramento CA
232 AM PST WED DEC 9 2015

.SYNOPSIS...
Fog could once again impact the morning commute for the central
and southern Valley. A few showers are possible across the north
today ahead of the next winter storm which will move in later
today through early Friday. Valley rain, heavy mountain snow, and
breezy winds will accompany this system and will impact trans
Sierra travel. Another system is expected to impact NorCal for
the end of the weekend.

&&

.DISCUSSION...
Patchy fog continues across portions of the central Valley
overnight and will be dense in some spots through the morning
commute. Some areas of drizzle already being reported early this
morning and have continued a mention in the forecast. Will
continue to monitor trends over the next several hours should the
need arise for a dense fog advisory. Shortwave out ahead of
impending winter storm will move across NorCal today and bring
some light showers across northern portions of the area.

Attention then quickly shifts to next winter storm that will
approach the area this evening. Precipitation will overspread the
area from NW to SE and continue into early Friday. Although parent
low is originating from the Gulf of Alaska, it will be pulling in
a healthy moisture stream from the Pacific. PWATS will approach
the 1-1.25 in range which is near the 97th-99th percentile for
this of year. Heaviest precipitation is expected on Thursday with
showers continuing across the mountains into Friday afternoon.
Precipitation amounts will range from around a half inch to 1.5
inches in the Valley to 2 to 4 inches in the mountains. Given
orientation of the jet, could see considerable rain shadowing in
the Valley due to the coastal range. Main impact in the Valley
will be slick roads and the possibility of localized street
flooding from leaf clogged storm drains. Still the possibility of
a few thunderstorms later Thursday that may locally enhance
rainfall amounts. Breezy winds will also accompany the system.

Snow levels will begin quite high today (~8000 feet), drop below
pass levels Thursday morning, and down around 4000-4500 feet by
Thursday evening. Given warmer origins of moisture feed, the snow
is expected to be heavy and wet in nature with lower snow ratios.
This should make for hazardous travel conditions across the Sierra
passes, especially Thursday afternoon and evening. Breezy to
locally gusty winds combined with heavy nature of snow may serve
to down tree limbs and power lines as well as reduce visibilities. Have
continued winter storm warning to highlight these impacts. Totals
will range from 12 to 24 inches near pass levels (locally higher
amounts near the crest) with 6 to 12 inches down to 5000 feet. A
few inches possible down to around 3500-4000 feet.

System will exit the region during the day Friday with a brief
break in precipitation Friday evening into early Saturday. Next
system begins to approach the area later Saturday but still some
model disagreement on timing. For now have continued the chance
for light showers across northern portions of the area.

CEO
&&

.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)

A second round of wet weather arrives Sunday except this storm
will be a bit cooler than the Thursday system. Another low
pressure system originating from the Gulf of Alaska will push
southward into NorCal Sunday morning with widespread showers
across our entire CWA by Sunday afternoon into the evening.
Ridgetop winds will be gusty...especially over the Sierra Crest.
Snow levels will start off between 5000-6500 ft Sunday morning
then lower to 2500-3500 ft overnight into Monday. Showers will
taper off by Monday afternoon with fairly dry weather on Tuesday.
The ECMWF shows another storm moving into NorCal on Wednesday, but
the GFS remains dry. Have gone with an "in between" forecast by
putting a slight chance of mountain showers for Wednesday, but
keeping the valley dry.  JBB

&&

.AVIATION...

A repeat of fog is happening again early this morning. Expect
IFR/LIFR conditions to be prevalent in the valley for much of
today with localized areas breaking out into MVFR in the afternoon.
Radar showing light showers approaching far NorCal coastline which
will probably impact the KRDD-KRBL vicinity later this morning
into afternoon. Winds at TAF sites will generally range 6-10 kts
for much of today...with winds becoming stronger late Wednesday
night into Thursday. JBB

&&

.STO Watches/Warnings/Advisories...
Winter Storm Warning from 4 AM Thursday to 4 AM PST Friday for
West Slope Northern Sierra Nevada-Western Plumas County/Lassen
Park.

&&

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 heavy rain, 2 heavy snow, 1 high wind. Local standard time, as filed.

Heavy Rain, Shasta

When: December 9, 6:00 AM PST to December 10, 6:00 AM PST
Where: Shasta County, 3.23 mi ENE of Shingletown Arpt
Reported by: Trained Spotter
Coordinates: 40.530, -121.760

There was 1.13 inches of rain over 24 hours, ending at 6 am.

Heavy Rain, Shasta

When: December 9, 7:00 AM PST to December 10, 7:00 AM PST
Where: Shasta County, 1.71 mi WNW of Sims
Reported by: Trained Spotter
Coordinates: 41.060, -122.360

There was 2.24 inches of rain over 24 hours, ending at 7 am.

Heavy Snow, Mt Shasta/Western Plumas County

When: December 9, 4:00 PM PST to December 11, 2:00 PM PST
Where: Mt Shasta/Western Plumas County forecast zone
Reported by: Broadcast Media

Heavy snow fell over the southern Cascades and into the mountains of western Plumas County, with over a foot of snow above 7000 feet. Snow caused travel difficulties on mountain roads. Lassen Volcanic National Park and Hwy 89 were closed on December 10th.

Heavy Snow, West Slope Northern Sierra Nevada

When: December 9, 6:00 PM PST to December 11, 6:00 PM PST
Where: West Slope Northern Sierra Nevada forecast zone
Deaths: 0 direct, 1 indirect
Property damage: $25,000
Reported by: Broadcast Media

Heavy snow fell over the Sierra, with around 1 to 2 feet above 7000 feet at ski resorts, 7-12 inches between 5000-7000 feet, 1 to 7 inches between 3000-5000 feet.

There were travel difficulties on highways in the Sierra, such as I-80 and Highway 50. Chain controls were in effect with slowdowns due to periods of whiteout conditions and very slippery roads, and multiple accidents were reported. There was a fatality a little after 5 am on the morning of December 11th, when a driver heading westbound on Highway 50 between Pollock Pines and Placerville lost control and crashed into a tree head-on. It was noted by the CHP that it was snowing at the time of the accident with reduced visibility, and the roadway was wet.

High Wind, Northern Sacramento Valley

When: December 10, 12:00 AM PST to 3:00 AM PST
Where: Northern Sacramento Valley forecast zone
Measured: 50 kt (58 mph) measured gust
Reported by: ASOS

Windy conditions occurred over the northern Sacramento Valley over the early morning hours on December 10th, with a peak of 57 mph at Redding Airport at 1:19 am PST. The heavy rain and strong winds across Northern California brought down trees and branches which knocked out power to thousands of customers early Thursday. More than 2,000 customers in Chico lost service. There were also outages reported across Shasta and Tehama counties.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Heavy Snow, West Slope Northern Sierra Nevada	2015-12-11	28	Male	Vehicle/Towed Trailer	Indirect

What these are

Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.
High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 2015 Every state in 2015 This day in weather history Warnings in California, December 2015

Sources

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: 612634, 612635, 604333, 604332, 604563.