We’re starting off the week with several chances of widespread frost and freezes as temperatures fall into the upper 20’s and low 30’s. But we see fire danger at critical or near critical levels for Wednesday and Thursday.

A Red Flag Warning begins Thursday night at 11 p.m. after gusty winds ramp up in the afternoon. Strong winds and low humidity are expected through Saturday afternoon. INTERACTIVE MAP: Track power outages across California The highest fire danger will be Friday morning 1 a.

When fire danger ramps up, you'll likely see two alerts issued by the National Weather Service: a fire weather watch and a red flag warning. Here's what you need to know about the alerts, what's different about them and what you need to do when they're in effect.