Fire weather watch to go into effect on Thursday for San Diego County, other parts of Southern California

The National Weather Service on Tuesday upgraded a fire weather watch that was set to go into effect this week to a full-blown red flag warning amid predictions of gusty winds and low humidity.

The original fire weather watch was set to begin late Wednesday night and remain in effect through Friday evening. The newly-imposed red flag warning will now go into effect at 5 a.m. Thursday and last until 5 p.m. Friday, the National Weather Service said.

A red flag warning means a combination of strong winds, low humidity and warm temperatures are expected to create conditions ripe for extreme fire b...