The National Weather Service has issued a red flag warning for critical fire conditions in a broad area of New England that includes the southeastern region and Dukes County. The warning will remain in effect through Monday night, the weather service said in an advisory. Low humidity levels and high wind conditions have combined to create hazardous conditions. “State fire weather managers have informed us that any fires that develop Monday will have the potential to spread rapidly. Outdoor burning is not recommended,” the advisory said.