Red flag warning extended through Tuesday after fiery Saturday in Northern California Sacramento Bee 5/10/2021 Vincent Moleski, The Sacramento Bee May 9—The National Weather Service's Sacramento office extended a red flag warning for the Sacramento Valley to last through Tuesday, indicating an additional day of high fire danger amid dry and warm weather. NWS forecasters originally issued the red flag warning from Friday through Monday evening, but on Sunday said it will last through 6 p.m. Tuesday, affecting the western Valley between Redding and Modesto, including all of Sacramento County. Portions of the northern Bay Area are also included. Temperatures have remained high as humidity stays low throughout Northern California. NWS meteorologists warned that fast-moving wind gusts, potentially as high as 40 miles per hour, could whip up fires across the region.