LOS ANGELES – Southern California braised Thursday, in the early stages of a potentially dangerous heat wave that forecasters predicted would send temperatures soaring to record levels, and the creation of conditions that can easily lead to forest fires to spread.
A massive dome of high pressure building in the east began to press on the region, which makes the cooling influence of the Pacific Ocean and setting the stage for widespread triple-digit temperatures Friday and into the weekend, even in some coastal areas.
“We could break — break — a number of records,” said meteorologist Alex Tardy of the San Diego National Weather Service office.
The San Diego County community of El Cajon, for example, was forecast to hit 110 degrees (43.3 degrees Celsius) on Friday, 24 degrees above normal for the date.
Authorities urged people to take precautions such as staying hydrated, watch out for the young and the elderly and taking advantage of the cooling centers located in various public facilities.
“There is a false expectation that the fans will help,” said Lisa Derderian, acting public information officer for the city of Pasadena. “All the fans really do is spread warm air, so we really want to encourage people to go to their local libraries, go to a cooling center.”
Forecasters, however, warned that people seeking relief from the heat by heading to the beaches may be confronted with the dangers of the ocean conditions generated by a south swell from former Hurricane Fabio combine with a northwest swell.
“The heat will be the dominant factor again in the next three days with a substory of dangerous surf and rip currents on the beaches,” the Los Angeles region National Weather Service wrote. “Someone who runs away from the dangers of the heat to the beaches will be faced with the dangers of the sea.”
The breaking of the waves could reach 10 feet (3 meters) on some of the beaches, the NWS said.
Southern California entered summer mild, to benefit from a good dose of “June Gloom,” the seasonal pressure of the cool maritime air and in the interior in the night and lingering through the morning — and sometimes longer before it fires off.
The beginning of high pressure, however, was clearing the skies and setting the stage for the potential weather records. The unimpeded sun in combination with additional warming as the air descends downslope in the direction of the sea will push temperatures well above normal, forecasters said.
Warnings for fire danger were in effect for parts of the region as a result of the heat, light north winds and relative humidity plunging into the single digits — conditions that the vegetation is ready to burn should a spark occur.
And the expected arrival on Sunday of monsoon moisture could bring the risk of lightning strike if the moisture content of the vegetation — the fuel for forest fires — is hovering near record lows.
“We are leaving a winter that was no winter,” Don said.
In the AMERICAN southwest, the weather service has an excessive heat warning for Phoenix, with temperatures expected to hit 114 degrees Fahrenheit (45.5 Celsius), the highest of the year so far. The warning extended to other parts of Arizona.
Associated Press writer Ariel Sun contributed to this report from Pasadena.