Active weather brought periods of heavy mountain snow, rain and gusty winds from December 12th through December 17th as multiple storms moved through the area. The strongest storm moved through over the December 13th through 14th timeframe and brought over 2 to 3 inches of rain, over 2 feet of heavy snow above 5000 feet, and gusty southerly wind gusts of 35 to 65 mph.
Every event with a place to put it. 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 STO wrote it up.
Active weather brought periods of heavy mountain snow, rain and gusty winds from December 12th through December 17th as multiple storms moved through the area. The strongest storm moved through over the December 13th through 14th timeframe and brought over 2 to 3 inches of rain, over 2 feet of heavy snow above 5000 feet, and gusty southerly wind gusts of 35 to 65 mph. Numerous downed trees and thousands of power outages were reported during this time, along with mountain highway closures and chain restrictions, with roadway flooding in the Central Valley.
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 13, 2:50 AM PST, 1 hour 10 minutes earlier.
Area Forecast Discussion
National Weather Service Sacramento CA
250 AM PST Fri Dec 13 2024
.SYNOPSIS...
An active weather pattern is forecasted to go into early next week
with rounds of mountain snow, rain, and gusty winds expected to
impact travel.
*Winter Storm Warnings: 4 AM Friday to 10 PM Saturday for
elevations above 3500 feet for the Shasta
County mountains
4 AM Friday to 10 PM Saturday for
elevations above 5000 feet for the Southern
Cascades & Sierra
* Wind Advisory: 10 PM Friday to Noon Saturday for portions
of the Sacramento Valley and Delta with
gusts up to 45 MPH.
.DISCUSSION...
The rain throughout the Valley has tapered off with lingering snow
showers over the Sierra. Looking at webcams, snow rates have
tapered off with little in additional accumulation expected early
this morning. As a result, our Winter Weather Advisory for the
Sierra and mountains of Shasta County has been cancelled. There
will be lingering snow showers with continued chain controls, so
please continue to exercise caution if attempting mountainous
travel.
Precipitation reports show around 0.50-1.50" in the Valley and
0.10-1.00" over the mountains in the last 24 hours. We will see a
brief lull in heavier precipitation for the next several hours
with the next wave looking to move from west to east beginning
around 6-8 AM this morning. This wave will last until SAturday
afternoon with lingering snow showers over the Sierra through the
evening. Friday night into Saturday late morning will be the
heaviest period of precipitation with things winding down by
Sunday morning. Valley forecasted totals with this wave are
0.75-2.25" north of I-80, and 0.10-0.75" southward. The foothills
are 0.75-3.00, up to 4" with the mountains 2.00-6.00", up to 8
inches along the Coastal Range and the Feather River Canyon
areas. In the Central Valley, the NBM shows a 40-80% chance of
amounts greater than 1.50" from this morning through Sunday
morning. For the mountains and foothills, there is a 50-85% chance
of amounts greater than 3 inches for the same timeframe. As you
move further north and up in elevation, amounts can be expected to
increase.
Periods of moderate to heavy snow will also accompany this weather
system. Lingering snow showers continue across parts of the Sierra
with snow redeveloping in earnest, first along the Coastal
Range this morning and to the Cascades and Sierra by morning's
end. This will continue through Saturday evening, tapering off
overnight into Sunday morning. Snow levels will generally be 4500
to 5500 feet As a result, Winter Storm Warnings have been issued
for Shasta County mountains, Southern Cascades, and Sierra. For
Shasta County, 8 to 24 inches is forecasted above 3500 feet,
locally higher along the peaks with wind gusts as high as 45 MPH.
For the Southern Cascades/Sierra, 1 to 3 feet above 5000 feet is
expected, locally higher along the Sierra crest with gusts up to
50 MPH. Models show a 50-80% chance of amounts greater than 2 feet
over the Sierra, highest north of I-80. The heaviest period of
snow will be Friday night into Saturday late morning over the
Sierra and Southern Cascades. Snow covered and slippery roads,
chain controls, and reduced visibilities will contribute to travel
delays and could become very difficult. Check the latest road
conditions from CalTrans online at quickmap.dot.ca.gov or dial
511.
Lastly, Friday late morning gusty winds begin to form with gusts
of 20-45 MPH, expected from Friday afternoon to Saturday late
evening. The strongest winds will be across the northeastern
foothills first Friday evening with the Delta joining in Saturday
morning. Saturday afternoon will see the winds begin to trickle
out and becoming light by Sunday morning. NBM probabilities have
a 60-95% chance of gusts stronger than 40 MPH, strongest over the
foothills and Delta. As a result, a Wind Advisory is in effect
from 10 PM Friday to Noon Saturday for southeast winds 15 to 25
mph and gusts of 45 to 50 MPH expected over the Sacramento and
Northern San Joaquin Valleys.
Sunday morning will see the active weather ending, with dry
weather expected by daybreak. Mostly sunny conditions and light
winds are expected. The next round of active weather begins on
Monday late morning, though this system will be quick and not
nearly as strong. Current snow amounts of around 4 to 10 inches
are forecasted for above 6000 feet, up to 12 inches near Lassen
NP. Rain with this wave will be considerably less with only
0.10-0.50" forecasted for the Valley and 0.25-1.25" over the
foothills and mountain areas. Snow levels will be between
3000-5000 feet on Monday, rising to 4500-5500 feet Tuesday
morning.
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)...
Clusters and ensembles are in good agreement regarding another
quick-moving system moving through the region on Monday. This
system does look to be weaker compared to the weekend system.
Widespread precipitation and accumulating mountain snowfall are
expected. The National Blend of Models (NBM) indicates a 30 to 60%
chance of a half inch or more of rain north of I-80, with up to
70% in the mountains. Snow levels will be between 3500-5000 feet
on Monday, rising to 4500-5500 feet Tuesday morning. The NBM
projects a 40 to 70% chance of 6 inches or more in the Sierra on
Monday. A few lingering snow showers will be possible over the
mountains Tuesday morning, before drier weather prevails Tuesday
through the remainder of the extended period.
&&
.AVIATION...
Widespread MVFR with areas of IFR and localized LIFR in
precipitation over the next 24 hours. Snow levels will be around
4000-5000 feet. Surface winds are expected to be southerly around
15-25 knots with gusts 35 to 50 kts by 01Z Saturday in the
Central Valley. Over the mountains, southwesterly gusts 30 to 50
kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 10 PM PST Saturday for Burney Basin /
Eastern Shasta County-Mountains Southwestern Shasta County to
Western Colusa County-Shasta Lake Area / Northern Shasta County-
West Slope Northern Sierra Nevada-Western Plumas County/Lassen
Park.
Wind Advisory from 10 PM this evening to noon PST Saturday for
Carquinez Strait and Delta-Central Sacramento Valley-Northern
Sacramento Valley-Southern Sacramento Valley.
&&The national radar mosaic for the moment the first event began.
5 heavy snow, 4 strong wind, 3 flood. Local standard time, as filed.
Nearby CoCoRaHS at similar elevations measured snow amounts of 1 to 5 inches. The National Operational Hydrologic Remote Sensing Center estimated snow amounts of 2 to 8 inches from December 13th through the 14th.
Nearby CoCoRaHS at similar elevations measured snow amounts of 1 to 5 inches. The National Operational Hydrologic Remote Sensing Center estimated 6 to 24 inches of snow, locally up to 30 to 48 inches at the highest peaks of Shasta County from December 13th through 14th.
Nearby CoCoRaHS at similar elevations measured snow amounts of 1 to 5 inches. The National Operational Hydrologic Remote Sensing Center estimated 6 to 24 inches of snow from December 13th through 14th.
Caltrans measured snow amounts of 12 to 30 inches from December 13th through December 14th. Ski resorts measured 1 to 3 feet of snow over the same timeframe. UC Berkeley Central Sierra Snow Lab measured 28.7 inches. Chain restrictions were in place at times over the mountain passes, and Interstate 80 eastbound was closed at Baxter for about 3 hours due to multiple spinouts.
CoCoRaHS measured snow amounts of 1 to 5 inches. The National Operational Hydrologic Remote Sensing Center estimated 6 to 24 inches of snow from December 13th through 14th, with locally higher amounts up to 4 feet at Lassen Peak.
California Highway Patrol reported a tree blown down across the highway along US Highway 50 east near the Bass Lake Road offramp.
California Highway Patrol reported a tree down on powerlines from gusty southerly winds.
California Highway Patrol reported 1 pine tree down across the whole road with two oak trees partially covering the northbound lane at Lumpkin Road and Forbestown Road from gusty southerly winds.
California Highway Patrol reported flooding from heavy rain leading to the closure of County Road 99W from Road 39 to Road 48 north of Willows.
California Highway Patrol reported multiple big rigs toppled over and vehicle spinouts due to strong winds that led to closure of Interstate 580 in both directions for approximately 5 hours until the winds subsided and vehicles could be turned upright.
California Highway Patrol reported 1 foot of water across the roadway on Fawndale Road from heavy rain.
California Highway Patrol reported multiple reports of roadway flooding along Interstate 80 in Sacramento from heavy rain.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2024Every state in 2024This day in weather historyWarnings in California, December 2024
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: 1222945, 1222946, 1222947, 1222948, 1222949, 1224372, 1224517, 1224521, 1224516, 1224524, 1224525, 1224534.