A round of Santa Ana winds is increasing fire danger across San Diego County this week, prompting possible power shut-offs and some school closures. The “first, most widespread and strongest” winds of the season were expected through Friday, which prompted a Red Flag Warning for the inland valleys and mountains, NBC 7 Meteorologist Francella Perez said. The powerful winds — which had already reached gusts of 55 mph on Wednesday, according to Meteorologist Greg Bledsoe — were combined with low humidity levels around 10% to create dangerous conditions for any potential wildfires that spark to grow quickly out of control, fire officials warned. “With the Red flag conditions, the lower humidities,  the dry fuels, the winds, and the warmer temperatures, any spark could potentially start and ignite a large and damaging wildfire,” Cal Fire San Diego Capt. Robert Johnson said. School closure for Nov. 7 Schools in the Mountain Empire Unified School District will be closed Thursday due to a power shut-off, according to the San Diego County Office of Education. Due to a power shutoff affecting multiple school sites, schools in the Mountain Empire Unified School District will be closed on Thursday, Nov. 7. https://t.co/PSib92OLp2— San Diego County Office of Education (@SanDiegoCOE) November 7, 2024 The announcement comes after schools in the district were closed Wednesday because of the high winds. Travel to and from school becomes dangerous and difficult during high wind events, especially for high-profile vehicles and school buses, the office wrote on X. Red Flag Warnings The dry, offshore winds will build throughout the day and peak Wednesday evening through Thursday morning. San Diego valleys will see gusts of 35 to 40 mph, with the strongest gusts in the eastern valleys. San Diego’s mountains and some inland valley locations could see gusts of close to 50mph, NBC 7 Meteorologist Brooke Martell said. The NWS has issued Red Flag Warnings from 3 p.m. Wednesday to 7 p.m. Thursday for the inland valleys. A Red Flag Warning is also in effect for our mountains including Palomar Mountain from 3 p.m. Wednesday until 11 a.m. Friday. Expect the strongest Santa Ana winds to arrive Tuesday night through Thursday evening. Strongest wind gusts on Wednesday as of 3 p.m. were: PEAK GUSTS SO FAR HAUSER MOUNTAIN – 56MPH HELLHOLE CANYON – 55MPH LA POSTA – 54 MPH CRESTWOOD – 52MPH BUCKMAN SPRINGS – 51 MPH OTAY MOUNTAIN – 45MPH ALPINE – 43MPH RAMONA – 40MPH Relative humidity will get down below 15% in some places and fuel moisture levels are critically low, despite getting the little rain last weekend. All of those factors will combine for severe fire danger, Martell said. Another round of gusty Santa Ana winds are expected tomorrow through Thursday. A Red Flag Warning is in effect from Wednesday through Thursday for most areas. Strong gusts and low humidity will lead to critical fire danger. #CAwx pic.twitter.com/1MeexLeghh— NWS San Diego (@NWSSanDiego) November 5, 2024 Weather pattern The unusual Santa Ana pattern means even residents along the coast were feeling the effects, Bledsoe said. Some coastal areas were seeing gusts of 25 mph on Wednesday with humidity levels below 20%. Bledsoe said this was creating conditions that meant it was warmer in downtown San Diego than it was in Borrego Springs. “This is due to the air sinking as it moves downhill towards the coast. Air warms as it sinks/subsides. We only really see that during a Santa Ana, and only see it at the coast when the Santa Ana is strong enough to make it that far west,” Bledsoe said. Winds will gradually weaken Thursday afternoon into Friday with lingering gusts of 35 to 45 mph possible Thursday night into Friday morning for our mountains, the NWS said. The rest of the week is expected to be dry, sunny, and chilly overnight. THURSDAY COAST: SUNNY – LOW 70s VALLEY: RED FLAG – 74 MTN: RED FLAG – 53 DESERT: SUNNY, 69 Possible power shut-offs San Diego Gas & Electric also warned they could shut off power to residents if strong winds have the potential to knock down powerlines, which can cause wildfires. SDG&E has alerted 24,700 customers in the area that they may have to shut off power to reduce wildfire risk. By 11 a.m. on Wednesday SDG&E had already cut off power to 683 customers in the Boulevard and Campo areas. The agency first sent the alert on Tuesday, adding that there would be no anticipated impacts to polling or ballot counting locations for Election Day. SDG&E began notifying customers who are most at risk of a power shut-off via phone, text messages and email. If you were contacted, be prepared to be without power through Friday, the agency said. If a power shut-off occurs, crews plan to restore power as quickly as safety allows. State regulators have approved these Public Safety Power Shutoffs (PSPS) as an important last-minute safety tool to reduce fire risk during dangerous weather conditions, according to SDG&E. If you were impacted by the shut-offs and need power, Community Resource Centers are open to you with Wi-Fi and phone and medical device charging. Community Resource Center locations can be found here. Potential communities Alpine Campo Reservation Capitan Grande Reservation Chula Vista Cuyapaipe Reservation Descanso El Cajon Escondido Inaja and Cosmit Reservation Jacumba Jamul Julian La Jolla Reservation La Posta Reservation Lakeside Los Coyotes Reservation Manzanita Reservation Mesa Grande Reservation Pala Reservation Palomar Mountain Pauma and Yuima Reservation Pauma Valley Potrero Ramona Rincon Reservation Santa Ysabel Santa Ysabel Reservation Santee Sycuan Reservation Valley Center Viejas Reservation Warner Springs This story uses functionality that may not work in our app. Click here to open the story in your web browser.