California, 2020

Winter Storm and Flood in California, November 7 to 10, 2020

November 7 to 10, 2020 · NWS SGX · 10 events in 8 counties and zones

An upper level trough brought notable lower elevation rain and mountain snow across Southern California from November 7th - 9th. The cold nature of the system also brought chilly temperatures to the region, especially in areas of the High Desert.

Where it happened

Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. 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
0
Injuries
0
Property damage
$2.0 million
Crop damage
None recorded
Events
10

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 SGX wrote it up.

An upper level trough brought notable lower elevation rain and mountain snow across Southern California from November 7th - 9th. The cold nature of the system also brought chilly temperatures to the region, especially in areas of the High Desert.

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 San Diego, CA wrote its last area forecast discussion before the first event at Nov 6, 8:45 PM PST, 3 hours 15 minutes earlier.

Area forecast discussion, Nov 6, 8:45 PM PST, 3 hours 15 minutes before
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The radar

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

Open the radar archive at this moment

Event by event

2 high wind, 2 winter storm, 1 strong wind, 1 winter weather, 1 heavy rain, 1 flood, 1 high surf, 1 frost/freeze. Local standard time, as filed.

Strong Wind, Coachella Valley

When
November 7, 12:00 AM PST to November 9, 8:00 PM PST
Where
Coachella Valley forecast zone
Measured
47 kt (54 mph) estimated gust
Property damage
$2.0 million
Reported by
ASOS
Coordinates
33.744, -115.994 (the zone’s center; the record gives no point)

Gusty winds occurred across the Coachella Valley over this period. Earlier in the period, a trained spotter reported a 46 mph wind gust with uprooted trees and broken tree limbs in the city of Coachella. The Thermal ASOS recorded a wind gust 54 MPH as well. In the late afternoon of the 8th, CHP report of downed light pole blocking Jackson St. just south of 58th Ave. where, Thermal ASOS had gusts to 33 mph at the time, however, a surfacing mountain wave may have produced higher gusts at this location.

High Wind, Apple and Lucerne Valleys

When
November 7, 12:00 AM PST to November 8, 8:00 PM PST
Where
Apple and Lucerne Valleys forecast zone
Measured
59 kt (68 mph) measured gust
Reported by
Utility Company
Coordinates
34.841, -116.178 (the zone’s center; the record gives no point)

Gusty winds occurred across the High Desert. Cushenbury Springs observation site reported a 68 MPH wind gust at 4:30 AM on the 7th.

High Wind, San Diego County Mountains

When
November 7, 2:00 AM PST to November 8, 4:00 PM PST
Where
San Diego County Mountains forecast zone
Measured
63 kt (72 mph) measured gust
Reported by
Department of Highways
Coordinates
33.028, -116.770 (the zone’s center; the record gives no point)

Gusty winds occurred in the San Diego mountains. UC San Diego HPWREN Network observation station measured a 72 MPH wind gust. Gusty winds led to a tree, approximately 14 inches in diameter, blocking road completely at Highway 76 / Highway 79 interchange. Observations near Lake Henshaw report wind gusts of 38-39 mph with sustained winds of 28-29 mph out of the southwest from 1:10 pm until 1:30 pm on the 8th.

Winter Weather, San Diego County Mountains

When
November 7, 8:00 AM PST to November 8, 4:00 PM PST
Where
San Diego County Mountains forecast zone
Reported by
Park/Forest Service
Coordinates
33.028, -116.770 (the zone’s center; the record gives no point)

Portions of the mountains in San Diego County received significant snowfall. Mt. Laguna measured a total of 7 inches, while Palomar Mountain measured 4 inches of snow.

Winter Storm, Riverside County Mountains

When
November 7, 8:00 AM PST to November 9, 8:00 PM PST
Where
Riverside County Mountains forecast zone
Reported by
Fire Department/Rescue
Coordinates
33.744, -115.994 (the zone’s center; the record gives no point)

Areas of heavy snow impacted the Riverside County Mountains, such as in Idyllwild, where the storm total snow observed was 6 inches.

Winter Storm, San Bernardino County Mountains

When
November 7, 8:00 AM PST to November 9, 8:00 PM PST
Where
San Bernardino County Mountains forecast zone
Reported by
Public
Coordinates
34.841, -116.178 (the zone’s center; the record gives no point)

Heavy snow fell in portions of the San Bernardino Mountains. Notable totals occurred at Big Bear Snow Summit Ski Resort, where 18 inches of snow fell at at 8,800 feet and 16 inches at Green Valley Lake. CalTrans closed a large portion of Route 38 on the 9th due to heavy snow, along with large power lines and trees down on the road.

Heavy Rain, San Diego

When
November 7, 8:00 AM PST to November 9, 8:00 PM PST
Where
San Diego County, 4.75 mi SSE of Pine Hills
Reported by
Official NWS Observations
Coordinates
32.990, -116.590

Areas of heavy rainfall occurred across the mountains and valleys of San Diego County. Notable totals occurred at Lake Cuyamaca with 3.98 inches of rain and Pine Valley with 3.31 inches of rain.

Flood, San Bernardino

When
November 7, 10:49 AM PST to 12:00 PM PST
Where
San Bernardino County, 5.86 mi N of Esperanza to 6.01 mi NNE of Yorba Linda
Cause
Heavy Rain
Reported by
Trained Spotter
Coordinates
33.955, -117.768

Trained spotter reports roadway flooding is occurring on carbon canyon road in various locations in carbon canyon. flooding is ranging from 1/2 an inch to 2 inches.

High Surf, Orange County Coastal

When
November 7, 4:00 PM PST to 7:00 PM PST
Where
Orange County Coastal forecast zone
Reported by
Lifeguard
Coordinates
33.677, -117.776 (the zone’s center; the record gives no point)

Lifeguards at Huntington Beach report high surf of 8 feet at 4 PM.

Frost/Freeze, Apple and Lucerne Valleys

When
November 9, 1:00 AM PST to November 10, 3:00 PM PST
Where
Apple and Lucerne Valleys forecast zone
Reported by
Official NWS Observations
Coordinates
34.841, -116.178 (the zone’s center; the record gives no point)

Portions of the High Desert saw cold temperatures with patchy areas of frost. The low temperature in Apple Valley dropped to 19 degrees on the afternoon of the 10th.

What these are

Strong Wind
Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.
High Wind
Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.
Winter Weather
Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.
Winter Storm
A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
Heavy Rain
Rainfall totals unusual for the place and season that did not produce a flood.
Flood
Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
High Surf
Large waves breaking on the shore that caused damage, erosion or casualties.
Frost/Freeze
Frost or temperatures at or below freezing during the growing season, usually filed for crop damage.

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

The same day elsewhere

More

Every storm in California in 2020Every state in 2020This day in weather historyWarnings in California, November 2020

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: 929960, 929962, 929495, 929488, 929489, 929494, 929503, 929964, 929533, 929963.