SAN DIEGO -- Thunderstorms began to develop in San Diego County Sunday, leading the National Weather Service to issue a severe thunderstorm warning for part of the county's mountainous back-country.
The Warner Springs area north of Julian was to remain under the warning starting at 3 p.m., and the first warning extended to 4 p.m. Sunday.
Increasing monsoon moisture will lead to the development of some storms focused over the mountains, though a few storms could occur in the valleys and along the coast as well, forecasters said.
Julian and Palomar Mountain both faced a 42 percent chance of thunderstorms Sunday. Ramona, Alpine and Escondido all had a 14-19 percent chance of precipitation, while most of the coastline had a chance below 10 percent.
Skies were cloudy throughout much of the region, and temperatures in the 70s along the coast gave way to temperatures in the 90s further inland.