National Weather Service radar map at 9:06 a.m. shows thunderstorm activity over Southern California.

Sudden downpours in the North County may slow down Wednesday morning’s commute.

Moderate to heavy rainfall could affect drivers along Interstate 15 and state Routes 78 and 79, according to the National Weather Service. Thunderstorms could possibly develop Wednesday morning in the vicinity of Oceanside, Carlsbad and Vista.

A chance of thunderstorms, mostly near the mountains, will continue into the afternoon, according to the weather service.

Drier and warmer weather is expected Thursday and Friday, forecasters said.

— City News Service

Chris Jennewein is founder and senior editor of Times of San Diego.