SAN DIEGO (FOX 5/KUSI) — A strong Santa Ana wind event is leading to dry and blustery conditions across San Diego County, raising concern for rapid fire spread if one were to break out. A Red Flag Warning is in effect through Thursday evening for San Diego County valleys due to dangerously low relative humidity and gusty northeast to easterly winds. The warning will remain in place for mountain areas through Friday. There are two rounds of concerning wind behavior while the alert is in effect. The first took place Wednesday morning just after sunrise. Top wind gusts were reported in Pine Valley at 55 miles per hour. San Diego County homeowners could soon find relief regarding home insurance Winds will surge again late Wednesday afternoon and into the evening hours. These look to be more widespread, even reaching the coastal communities after 5 p.m. Along the Interstate 8 corridor, top wind gusts could range from 40 to 60 miles per hour. Beaches could see strong wind gusts of up to 30 miles per hour. With relative humidity dropping below 15% for nearly all areas this afternoon, it will only add to the dryness of the region and thus increase the fire danger everywhere.  It will be a colder Santa Ana wind event as a storm is attached to it near the Rockies/Great Basin area. This means once the winds die down, cold air will remain and drop overnight temperatures in some areas — like Ramona, Oceanside and Poway — down to the mid-30s into Thursday. Winds back off a bit going into Thursday afternoon, but given the persistent dry conditions, elevated fire danger will still be a concern going into Friday.  During a Red Flag Warning, the National Weather Service stresses to prepare for an emergency in the event of an evacuation. This includes bringing flammable objects inside, having an emergency kit ready to go, and avoiding use of any equipment that may generate sparks. More information on how to prepare in the event of a fire can be found here. To reduce the risk of wildfires, San Diego Gas & Electric has begun rolling power shutoffs for thousands of customers in the county's backcountry. Several schools were also closed due to the inclement weather on Wednesday. FOX 5/KUSI's Danielle Dawson contributed to this report.