A series of cold upper lows impacted Southern California on March 16-20th. Widespread precipitation occurred with the first upper low on March 16th, continuing through the 17th.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 SGX wrote it up.
A series of cold upper lows impacted Southern California on March 16-20th. Widespread precipitation occurred with the first upper low on March 16th, continuing through the 17th. Snow occurred on the 18th in the mountains when the upper low moved south over far northern Baja and into the deserts. A secondary cold upper low dropped south from Lake Tahoe on March 18th and 19th, bringing more widespread precipitation to the area. Heavy showers occurred on March 19th in the inland valleys as well as snow in the mountains. Total rainfall ranged from a few tenths of an inch along the coast, up to 0.75 in the valleys. Mountain areas saw up to 1.20 of precipitation. Hourly rainfall rates of 0.25 to 0.55 inches per hour were observed on March 18th and 19th. Snowfall was mainly confined to the San Bernardino Mountains, where up to 6 inches of snow fell on the highest peaks. Funnel clouds were observed along the coast on March 16th and 19th.
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 Mar 16, 9:22 AM PST, 38 minutes earlier.
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</html>The San Diego radar (KNKX), 40 km away, was scanning. The volume nearest the first event began at 18:03 UTC.
2 funnel cloud, 1 heavy snow. Local standard time, as filed.
Fire department reported funnel clouds or waterspouts off the coast of Oceanside and Carlsbad. They confirmed that there were funnel clouds, and possibly waterspouts but it was too far offshore to tell.
Snow fell in the San Bernardino Mountains on March 18th and 19th. Snowfall totals were highest at Green Valley Lake, Running Springs and Lake Arrowhead where 5-6 inches of snow fell. Mt Baldy and Arrowbear Lake picked up 4 inches of snow. Lower elevations such as Forest Falls, Crestline and Wrightwood received 2 inches of snow.
Coronado Lifeguards reported 2 funnel clouds/waterspouts off the coast of Coronado on March 19th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2020Every state in 2020This day in weather historyWarnings in California, March 2020
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: 882332, 882333, 882334.