SAN DIEGO COUNTY, Calif. — Lack of rain, gusty offshore Santa Ana winds and low relative humidity have led to critical fire concerns across San Diego County this week as all of these factors are hitting at the same time, a weather phenomenon that’s been common in San Diego County recently.
A High Wind Warning is in effect for San Diego County coastal areas, inland valleys and mountains communities beginning Tuesday at 4:00 p.m. Offshore, dry winds will pick up to speeds between 30 and 40 mph at times with gusts up to 75 mph with most intense gusts expected across local mountain ranges.
A Red Flag Warning is also in effect for San Diego County inland valleys and mountains starting Wednesday at 4:00 a.m.
In an effort to reduce the risk of wildfire in certain areas of San Diego County, San Diego Gas & Electric has issued a Public Safety Power Shutoff warning to more than 65,000 customers in high-impact areas. The period of concern is Tuesday, January 7, starting at noon through Friday, January 10 at 4:00 p.m. Click here to see the impacted areas.
In December, strong Santa Ana winds brought critical fire danger, power outages, school closures, and even overturned semi-trucks to San Diego County.
Following a very wet 2023-2024 water year, plenty of vegetation grew and led to sprawling green hills and valleys. But by January, all of that vegetation has turned dry and brown and only serves as fuel for fires.
Since October 1, 2024, San Diego County has stayed far below normal on rain totals regardless of where in the county you look. In some cases, normal rainfall in previous years would be upward of 3 to 4 inches at this point in January but this year is far less. As we push further into winter with no significant rain, the fire danger continues to climb.
Santa Ana Winds occur when air from the desert region blows westward toward the California coast. This results in dry air that flows est to west over the mountains and towards the valleys and coast of Southern California. Santa Ana winds typically feel warm because as the cool desert air moves down the side of the mountain, it is compressed, which causes the temperature of the air to rise. We tend to see relative humidity plummet and temperatures soar during offshore wind events like this.
These winds create high fire conditions not only for a fire to start but offshore, Santa Ana winds are the perfect fan needed to allow a fire to explode in size once it starts.
The water year restarts every year on October 1 and measures the rain totals for the season through the following September. When rain totals are below average, the vegetation that once was green turns brown and dry and can serve as fuel for wildfires. The saturated ground can help mitigate fire risk substantially, but the opposite tends to elevate our fire risk. The sooner and more frequently we see substantial rainfall, the lower our risk is for a wildfire to start and spread rapidly.
When a region is in critical fire danger, power companies tend to shut off power in pre-planned ways in order to prevent electrical equipment from sparking or starting fires. It is also because electric consumption tends to climb with warmer temperatures (usually thanks to A/C needs) and can lead to overall stress on the power grid. When you combine the risk of fire with planned power shut-offs, many school districts will close. Schools can also be used as monitoring sites for fire crews in the event of a fire starting.
CalFire has built a list of things to have ready in case you and your family are evacuated during any wildfire or disaster.
Ensure your wildfire ‘Go Bag’ includes:
- A 3-day supply of non-perishable food & 3 gallons of water per person
- A map with at least 2 evacuation routes
- Necessary prescriptions or medications
- A change of clothes & extra eyeglasses/contact lenses
- Extra car keys, credit cards, cash, or traveler’s checks
- A first aid kit & sanitation supplies
- A flashlight & battery-powered radio with extra batteries
- Copies of important documents (birth certificates, passports, etc.)
- Pet food & water
Always have sturdy shoes and a flashlight near your bed, ready for sudden night evacuations.
If time allows, consider adding:
- Valuables that are easy to carry
- Family photos and irreplaceable items
- Personal computer data on hard drives and disks
- Chargers for cell phones and laptops
