Red flag up through Sunday

A “red flag’’ warning, signaling a high risk of wildfire, was extended today through 8 p.m. Sunday in the valleys and mountains of San Diego County.

The alert, which was issued Wednesday morning, was to have expired Friday night, but the National Weather Service subsequently extended it twice - first until 11 p.m. Saturday, then by yet another 21 hours - as forecasts showed that dry air and warm temperatures are likely to linger in the region.

And the warning - which indicates that heat, high winds and low

humidity will create the potential for “explosive fire growth’’ - may have to

be extended into Monday, the weather service advised.

Local offshore winds gusting under 25 mph are expected this afternoon through and below passes and canyons amid very warm high temperatures, according to the NWS.

The weather pattern will likely bring several hours of humidity readings below 10 percent through early evening, with poor overnight recovery.

Atmospheric moisture levels may increase slightly near the coast on Sunday, but not much change is expected farther inland, according to the NWS.