Heavy Snow in California, February 23 to 24, 2010

Name: Heavy Snow in California, February 23 to 24, 2010
Start: 2010-02-23T10:10
End: 2010-02-24T06:10
Location: California

February 23 to 24, 2010 · NWS MFR · 2 events in 2 counties and zones

Strong upslope flow in Northern California resulted in heavy snow accumulations.

Where it happened

Every event with a place to put it; 2 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: None recorded
Crop damage: None recorded
Events: 2

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 MFR wrote it up.

Strong upslope flow in Northern California resulted in heavy snow accumulations.

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 Medford, OR wrote its last area forecast discussion before the first event at Feb 23, 9:20 AM PST, 50 minutes earlier.

Area forecast discussion, Feb 23, 9:20 AM PST, 50 minutes before

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Hazardous weather outlook, Feb 23, 4:33 AM PST, 5 hours 37 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. Local standard time, as filed.

Heavy Snow, South Central Siskiyou County

When: February 23, 10:10 AM PST to February 24, 6:10 AM PST
Where: South Central Siskiyou County forecast zone
Reported by: Department of Highways
Coordinates: 41.593, -122.540 (the zone’s center; the record gives no point)

The Snowman Summit Caltrans station measured 1.62 inches of precipitation in 20 hours from 23/1010 PST to 24/0610 PST. The temperature during this time was 29F to 34F. Using a ratio of 10:1, Heavy Snow Warning criteria was met that evening around 23/2040 PST. In addition, a spotter in Mt. Shasta City reported 6 inches of snow with 0.75 inches of precipitation in 12 hours ending at 23/2300 PST.

Heavy Snow, North Central & Southeast Siskiyou County

When: February 23, 10:10 AM PST to February 24, 6:10 AM PST
Where: North Central & Southeast Siskiyou County forecast zone
Reported by: Department of Highways
Coordinates: 41.593, -122.540 (the zone’s center; the record gives no point)

The Snowman Summit Caltrans station measured 1.62 inches of precipitation in 20 hours from 23/1010 PST to 24/0610 PST. The temperature during this time was 29F to 34F. Using a ratio of 10:1, Heavy Snow Warning criteria was met that evening around 23/2040 PST. Even though this station is in CAZ082, it is assumed that Heavy Snow Warning criteria was met for CAZ083 as well due to similar terrain and weather conditions in that area.

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.

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

The same day elsewhere

Every storm in California in 2010 Every state in 2010 This day in weather history Warnings in California, February 2010

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 2026-10-01. Each event’s entry at NCEI: 209963, 209964.