Good morning and happy Friday eve. Forecasters say Santa Ana is creating particularly dangerous fire conditions for mountains and valleys.

Colder temperatures

Expect cooler weather throughout Southern California with highs from coast to valleys in the 70s, low 70s for coastal areas, mid 70s for valleys and inland areas. Low desert communities will also see highs in the mid-70s, while conditions will be colder in the high desert, with highs in the mid-to-low 60s.

Overnight lows tonight will be cold for most of the South: lows around 40 degrees for coastal areas, valleys and low deserts, to low 30s for the high desert. That means if you live in the high desert, be sure to bring your plants indoors to prevent frost from affecting them.

Wind and fire conditions.

The National Weather Service calls today’s wind conditions in Santa Ana “particularly dangerous.”

Red flag warnings are in effect through this afternoon for Los Angeles and Ventura counties, where forecasters anticipate wind gusts of up to 80 mph in the mountains and foothills.

Isolated gusts up to 100 mph are possible in the San Gabriel Mountains. Orange County is also under a red flag warning until 6 pm today, where wind gusts could reach up to 40 mph.

Meanwhile, red flag conditions are extending for the mountains of Riverside County through Friday, but wind gusts there are much lower, up to 50 mph.

Most of southern and central Ventura County, including the western Santa Monica Mountains, are under a heavy smoke advisory until 9 a.m. due to the Mountain and wide fires that exploded yesterday.

Poor air quality will affect much of the south today as winds blow dust and ash everywhere. Here are some tips on how to protect yourself from forest fire smoke.