Name: Flood and Heavy Snow in California, January 30 to 31, 2023
Start: 2023-01-30T00:00
End: 2023-01-31T18:00
Location: California

Where it happened

Every event with a place to put it; 3 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: $1,000
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 SGX wrote it up.

Another winter storm impacted Southern California January 30th through the 31st. A closed upper level low pressure system led to widespread rain in the coasts and valleys as well as a few inches of snow in the mountains, with the heaviest snow in the San Bernardino Mountains. A few thunderstorms also occurred over the San Diego County Valleys, enhancing rainfall in these areas.

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 Jan 29, 8:57 PM PST, 3 hours 3 minutes earlier.

Area forecast discussion, Jan 29, 8:57 PM PST, 3 hours 3 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 heavy snow, 1 heavy rain, 1 flood, 1 strong wind. Local standard time, as filed.

Heavy Snow, San Bernardino County Mountains

When: January 30, 12:00 AM PST to 7:00 AM PST
Where: San Bernardino County Mountains forecast zone
Reported by: Department of Highways
Coordinates: 34.841, -116.178 (the zone’s center; the record gives no point)

Snow fell across many of the mountain communities in the San Bernardino Mountains generally at elevations near or above 5000 feet. Areas from Crestline to Running Springs to Green Valley lake received 4-6 inches of snow by sunrise on the 30th. The Mt Baldy Ski Resort also received 5 inches of snow.

Heavy Snow, San Diego County Mountains

When: January 30, 12:00 AM PST to 6:00 PM PST
Where: San Diego County Mountains forecast zone
Reported by: Trained Spotter
Coordinates: 33.028, -116.770 (the zone’s center; the record gives no point)

A trained spotter reported storm total snowfall of 5.5 inches at Birch Hill on Palomar Mountain.

Heavy Rain, San Diego

When: January 30, 11:00 AM PST to January 31, 6:00 PM PST
Where: San Diego County, 1.34 mi SSW of Escondido to 0.49 mi SSW of San Marcos
Reported by: Mesonet
Coordinates: 33.113, -117.081

Heavy rain with a few embedded thunderstorms occurred mainly over the San Diego County Valleys on January 30th, generally between the hours of 11 AM and 6 PM. Rainfall totals of 0.50-1.00 inch were common, with a few localized areas near San Marcos and Escondido receiving about 1.10 inches.

Flood, Orange

When: January 30, 1:00 PM PST to 2:00 PM PST
Where: Orange County, 0.9 mi SW of Red Hill to 0.99 mi NW of Tustin
Cause: Heavy Rain
Reported by: Department of Highways
Coordinates: 33.740, -117.830

Caltrans report of water flooding the HOV lanes at SR-55 and I-5 Northbound. Clogged drains likely played a part as observed rainfall amounts at the time were 0.18 inch over the previous 3 hours.

Strong Wind, San Bernardino and Riverside County Valleys - the Inland Empire

When: January 31, 2:00 PM PST to 3:00 PM PST
Where: San Bernardino and Riverside County Valleys - the Inland Empire forecast zone
Measured: 35 kt (40 mph) measured gust
Property damage: $1,000
Reported by: Trained Spotter
Coordinates: 34.293, -116.086 (the zone’s center; the record gives no point)

A large branch was torn off from a pine tree in Hunt Park. Widespread wind gusts 30 to 35 mph occurred in this region between Corona and Riverside.

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.
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.
Strong Wind: Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.

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

The same day elsewhere

More

Every storm in California in 2023 Every state in 2023 This day in weather history Warnings in California, January 2023

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 2026-09-30. Each event’s entry at NCEI: 1074523, 1074538, 1074543, 1074521, 1074522.