A cold low-pressure system was moving eastward Wednesday after delivering surprisingly intense lightning, thunder, hail, snow and rain to San Diego.
About a quarter of an inch to half an inch of rain fell in the county, according to the National Weather Service (NWS).
One inch of snow was reported at Birch Hill, near Palomar Observatory, the NWS said. Snow was also reported at Mount Laguna overnight.
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The snow caused schools in Julian to close Wednesday and have a late start on Thursday, according to the San Diego County Office of Education.
Spencer Valley School District will also be closed Wednesday for a snow day and Warner Unified School District will have a two-hour late start, the county said.
Small hail, thunder and lightning were also reported up and down the coast and as far east as Escondido, NWS said.
NWS meteorologist Alex Tardy says it was all due to a cold system that moved down from the arctic.
“It definitely packed the punch," he said. "It didn’t bring up an atmospheric river, it didn’t bring up any moisture from the tropics, but it brought a lot of cold air and what that means meteorologically is a lot of instability."
The wintry blast arrived just days after Southern California baked in summerlike weather. Tardy said that was due to a combination of factors, one of which was days of strong Santa Ana winds.
“But we also had the big dome of high pressure of dome of heat sitting right over us along the coast," he said. "So the combination of the two basically removes the sea breeze and the marine air ... and we become the deserts."
There were 190 cloud-to-ground lightning strikes and another 165 in the clouds across Southern California, the NWS said.
Southern California weather was forecast to remain windy into Thursday while also warming. Santa Ana winds were expected to return late in the week.
