Pop-up thunderstorms over the mountains and deserts could spread rainfall over the county, weathercasters said.
Light showers touched down in parts of Julian and Mount Laguna Wednesday morning, NBC 7 Weathercaster Llarisa Abreu said.
"We're not talking about significant rain or heavy pockets of rain but it is a little bit more widespread," Abreu said in NBC 7's First Alert Forecast.
Two plumes of moisture were expected to converge later in the evening to bring a chance of thunderstorms over the mountains and deserts again late Wednesday afternoon.
The chance of thunderstorms was expected to last until Thursday.
Some light sprinkles could reach as far west as downtown San Diego, but the chance was slim, Abreu said.
Mostly, areas west of the mountains would see cloudy skies and muggy conditions.
