Topline:
A heat advisory is in place for much of Southern California from 10 a.m. Wednesday through Monday.
The heat: Temperatures are expected to climb steadily this week. Inland valleys in L.A., Riverside and San Bernardino counties will see highs between the mid-90s and about 105 degrees. Areas closer to the coast, including downtown Los Angeles and most of Orange County, will hit the 90s, while beaches hover mostly in the upper 70s. Humidity also continues to add to the discomfort, making it harder to cool down.
Fire risk: Despite higher-than-normal humidity, a combination of dry brush and wind will also increase the likelihood of fires sparking in some places. The risk will be concentrated in places prone to high winds, including parts of the 5 Freeway corridor in northern L.A. County, especially around the Grapevine, and southern Santa Barbara County.
Beach conditions: Forecasters expect dangerously large waves and strong rip currents to persist through the weekend along the Southern California coast.
Read on … to learn more about what’s driving these uncomfortable conditions.
We hope you’ve gotten used to the hot weather, because it’s going to be here for a while.
The National Weather Service has issued yet another heat advisory for much of Southern California, less than a week after other high-temperature warnings were lifted.
This week’s advisory will be in place from 10 a.m. Wednesday through Monday. Forecasters expect temperatures to climb steadily over the course of Wednesday and Thursday.
The San Fernando Valley, San Gabriel Valley and other inland areas in L.A., as well as Riverside and San Bernardino counties, will likely see highs ranging from the mid-90s to about 105 degrees. Areas closer to the coast, including downtown Los Angeles and much of Orange County, will hit the 90s. Beaches will hover mostly in the upper 70s.
Humidity will also add to the discomfort. Even though it’s decreasing slightly, it makes cooling down harder, especially at night.
People who work outdoors or do not have air conditioning are especially at risk from the heat and humidity, along with people over 65, young children and other sensitive populations.
Making sense of heat forecasts
Southern Californians are no strangers to hot weather in the summer, but heat waves are getting hotter, longer and more frequent as the climate changes.
So you should know the words forecasters use to describe these weather events — and the risks they pose.
- Heat advisory: Advisories are issued when temperatures are expected to be hot enough to cause discomfort and potentially lead to heat-related illnesses, especially for more vulnerable populations like young children and the elderly.
- Extreme heat watch: Watches are essentially forecasts for upcoming periods of extreme heat. Forecasters say heat watches often cover wide areas and will be revised into more focused warnings and advisories as conditions become clearer over time. Watches are a good time to prepare for extreme heat.
- Extreme heat warning: Warnings are issued when heat levels are or will likely become extremely dangerous. Under extreme heat warnings, it's a good idea to avoid strenuous outdoor activity, stay hydrated and help loved ones and pets stay cool.
Learn more >>
Fire risk
Forecasters are warning that conditions are ripe for fires, driven by a combination of wind and dry vegetation.
Southern California hasn’t seen much rain recently, despite the humidity, leaving plants with little moisture and turning them into the perfect fuel.
“Even though the air feels kind of moist, we're in the time of season where it doesn't matter. The fuels are dry and they're ready to go,” said NWS meteorologist Ryan Kittell.
Kittel said people should take extra care with anything that could create a spark, and residents in fire-prone areas should remain aware of their surroundings in case a fire starts.
The fire risk is likely to be concentrated in a few specific areas that will experience higher winds than others, including parts of the 5 Freeway corridor in northern L.A. County, especially around the Grapevine, and in southern Santa Barbara County.
For most of the region, though, winds should stay fairly mild.
Dangerous beach conditions
Southern Californians also have to contend with some ocean-specific risks this week.
Forecasters expect dangerously large waves and strong rip currents to hit the coastline at a time when the heat may drive more people to the beach. The conditions are expected to persist through the weekend.
If you decide to head to the beach, it’s a good idea to ask a lifeguard for advice on the conditions before entering the water. It’s also recommended to swim only near occupied lifeguard stands, stay off of rock jetties and avoid turning your back to the waves.
South-facing stretches of coastline will bear the brunt of the swell, which is being driven by two tropical storms churning hundreds of miles away in the Pacific Ocean.
“Those two systems generated the winds and the waves locally that are pushing towards us, and so that's creating elevated surf and some stronger currents than normal,” Kittel said.
The swell is not expected to cause significant coastal flooding as high tides remain relatively low.
