A fire danger sign with the iconic Smokey Bear. Image courtesy Centers for Disease Control

A rare thunderstorm Friday night is expected to quickly give way to conditions ripe for wildfires by late Sunday, forecasters said.

A storm system arrived Friday evening and unleashed heavy rain and lighting on the San Diego area, with precipitation amounting to a few tenths of an inch in most places.

The National Weather Service predicted scattered showers to persist through Saturday night. By Sunday night, Santa Ana winds of 25-35 mph — with isolated gusts up to 70 mph possible in some areas — were expected to move in.

Humidity was expected to drop rapidly to 5-10 percent on Monday as well, prompting the NWS to issue a fire weather watch for San Diego County, as well as Orange, Riverside and San Bernardino counties, from 3 a.m. Monday to 8 p.m. Tuesday.

The watch was set to be in effect for mountains, foothills and valleys, but the conditions could cause fire to spark anywhere.

Moisture from the thunderstorm will help to alleviate the fire threat, but fuels will dry quickly on Monday, NWS forecasters said.

Winds were predicted to gradually decrease Tuesday night and Wednesday, and conditions will be warm and sunny the remainder of the week, forecasters said.

–City News Service