Much of California faces a climate double whammy this week as a dangerous heat wave and high fire risk loom at a time when millions of people will be outdoors celebrating Independence Day.
Temperatures in the Sacramento Valley can reach 115 degrees, according to Kate Forrest, a meteorologist with the National Weather Service in California’s capital. A heat warning for the area will begin Tuesday and is expected to last until at least Saturday.
“We expect elevated heat and extreme heat risk across most of inland California,” Forrest said. “This heat will be a prolonged event.”
Forecasters expect the heat wave to begin Tuesday in inland California and then widen in the Pacific Northwest and deepen in Southern California later in the week. Excessive heat watches, warnings and watches will cover the West on Tuesday, from southern Oregon to the low desert in southeastern California, according to the National Weather Service.
The high temperatures are the result of a strong high pressure system that will persist in the region.
“High pressure systems force air downward, causing the air to compress and increase the temperature,” Forrest said. “That air remains stagnant.”
State officials are preparing for the heat. Governor Gavin Newsom has directed emergency officials to activate the state’s operations center – its central command station during emergencies – his office said in a press release.
Hot weather can be above 80 degrees F even at night in some places. On Friday, most of inland California will face “extreme” conditions, according to the HeatRisk map, a tool from the Centers for Disease Control and Prevention and the National Weather Service. The designation means agencies expect impacts to healthcare facilities and infrastructure.
The area around Medford, Oregon, and other southern parts of the state are also under an excessive heat watch through Saturday.
“If you have neighbors who don’t have air conditioning, check on them more often,” said Brad Schaaf, chief meteorologist at the National Weather Service in Medford.
Some forecast models suggest the Medford region could set a record for the number of consecutive 100-degree days, Schaaf said. The region suffered 10 consecutive days of this type in 1967.
Dangerous fire conditions will accompany the sharp rise in temperatures on Tuesday in both states.
Pacific Gas & Electric said Monday that power outages are likely in 10 California counties on Tuesday, given the high winds and dry conditions expected across central California. Shutoffs are designed to proactively reduce the risk of wildfires in areas where winds can down power lines or cause trees to fall on them. Some outages are also expected on Wednesday.
But these precautionary outages are likely to leave some communities without electricity as the mercury rises to dangerous levels.
Forrest predicted up to a 45% chance of wind gusts above 35 mph in the Sacramento Valley area, with humidity levels that could drop into the single digits — a recipe for fast-moving wildfires.
Plants are dry and ready to burn, especially at elevations below 3,000 feet, she added.
“If ignition starts, it will spread,” Forrest said.
It’s a difficult time as the Fourth of July celebrations begin with fireworks.
“It’s not ideal,” Schaaf said. “We want to ask everyone to use extreme caution when participating in activities that cause sparks, such as using fireworks.”
The California Department of Forestry and Fire Protection is tracking 13 active fire incidents, only four of which have burned more than 100 acres.
In the Southwest, the wildfire season has already turned deadly. Two people died and 500 homes were destroyed in a fire that devastated the community of Ruidoso, New Mexico last month.
Climate change increases the likelihood of fires and heat waves. Last year, the non-profit group Climate Central calculated how the number of fire days has changed in the U.S. from 1973 to 2022. The analysis found that the Sacramento Valley experiences nearly two more weeks of fires, on average, than it did 50 years ago.
Meanwhile, heat waves are occurring more frequently and lasting longer, according to data from the US Environmental Protection Agency. US cities, on average, experienced two heat waves a year; now, they typically get six. These heat waves also last about a day longer, the data suggests.
This article was originally published in NBCNews. with
