SAN DIEGO -- Strong and gusty Santa Ana winds, low humidity and warm temperatures prompted the National Weather Service to issue a red flag fire warning Friday denoting a strong risk of wildfire in San Diego County.
Along with low humidity levels, the strong Santa Ana winds blowing northeast are to blame for the fire danger, with winds of 15 to 25 mph in the forecast and gusts near 45 mph possible in the county mountains, according to the Santa Ana Wildfire Threat Index. Humidity was expected to drop to 15-20 percent Friday.
The red flag warning went into effect at 3 Friday morning and will last until 10 p.m. Friday evening for the county mountains and valleys.
Vegetation will be dry enough to result in rapid spread of flames should ignition occur, according to the wildfire threat index.
San Diego County residents were urged to avoid outdoor burning during the warning.
Warm seasonal temperatures were also expected to add to the potential fire danger. High temperatures Friday will be 85 to 87 degrees near the coast and inland, 86 to 91 degrees in the western valleys, 79 to 84 in the foothills, 69 to 76 in the mountains and around 87 in the deserts, NWS forecasters said.
According to Cal Fire San Diego Unit Chief Tony Mecham, residents should take measures to safeguard themselves and their homes, including clearing flammable vegetation to create roughly 100 feet of "defensible space" around residences; developing an emergency evacuation plan; and planning in advance which important documents, heirlooms, photos and medications to quickly gather prior to any evacuation.
County officials also recommend that residents register their mobile phones on the county's emergency-alert system, AlertSanDiego, and download the free SD Emergency App. Residents can learn more about fire safety and preparedness online at ReadySanDiego.org.
"The humidity will recover tonight and not be as low on Saturday with gusty winds diminishing Saturday afternoon," NWS forecasters said.