The National Weather Service is changing the criteria for so-called red flag warnings of fire danger in southwestern California to make them more meaningful.
Fire officials say the standards effective Thursday in San Diego and adjacent counties could lead to fewer warnings and more accurately gauge the fire risk.
The criteria emphasize the combination of wind and low relative humidity rather than low humidity alone. Previously, a warning could be issued if relative humidity was expected to fall to 10 percent or lower for 10 hours or more regardless of whether there was wind.
Bruce Risher of the U.S. Forest Service says fewer warnings will make residents pay more attention when a red flag warning is issued.
The warning region includes Orange County and western Riverside and San Bernardino counties.
