Red flag wildfire alert issued

A “red flag’’ wildfire alert will be in effect from this evening through late Saturday afternoon for the East County valleys and mountains, the National Weather Service advised this afternoon.

The 21-hour span covered by the warning - which cautions of “explosive fire-growth potential’’ caused by dry, windy conditions - will begin at 7 p.m., according to the NWS.

The period is expected to be marked by sustained winds reaching 25-35 mph out of the east and northeast, and relative humidity levels dipping below 10 percent at times in the subject areas.

The winds will likely begin diminishing around 4 p.m. Saturday, but the atmosphere will continue to be extremely dry in the region, according to the weather service.