With the spring daffodils barely gone, Southern California braced Wednesday for a weeklong blast of triple-digit temperatures and heightened fire danger across the region.
And when the weather year ends Monday, Los Angeles expects to tally its sixth driest year on record.
"This is definitely the first protracted heat wave of the season," said Bill Patzert, climatologist for the Jet Propulsion Laboratory in Pasadena. "And it's come early.
"On one side of the country, it's raining and stormy. And the other, bone dry with extreme heat. And the pattern is supposed to hold for a week."
Forecasters said a massive high-pressure system that has eclipsed much of the West is expected to increase temperatures by up to 10 degrees per day through the weekend before gradually tapering off by Thursday. In the meantime, the East Coast faces massive storms and floods.
As unseasonal wildfires have burned throughout the West, the early summer heat wave precedes the prolonged heat incidents normally seen in late summer or fall.
"It's going to be a significant heat wave of the season," said David Sweet, a meteorologist at the National Weather Service in Oxnard. "I think the fire danger is significant, in near-critical conditions" -- but not quite dry enough to issue a red-flag warning, he said.
The weather service issued an excessive heat warning from the Inland Empire to the low desert, where the mercury Saturday was expected to hit 97 degrees in Ontario, 102 in San Bernardino and a smoking 117 degrees in Palm Springs.
An excessive heat watch was also issued beginning Friday for mountains across the Southland, where lower elevations were expected to reach 108 degrees and record temperatures up into the 90s at higher altitudes.
Motorists en route to Las Vegas -- expected to hit 117 -- will brave a searingly hot stretch and were warned to pack extra water and be prepared for a long drive home. "It's bumper-to-bumper traffic, and you're going 10 miles per hour because cars are breaking down because of the high heat," said Ken Clark, an Inland Empire meteorologist at AccuWeather.
With low humidity and extended heat, children, seniors and those with chronic ailments were warned to guard against heat exhaustion, stroke and illness. To provide relief for the elderly and others, the Los Angeles County Department of Public Health will open cooling centers throughout Los Angeles County, announced Supervisor Michael D. Antonovich. For a complete list, call 323-459-3779, or go to publichealth.lacounty.gov.
Few parts of Los Angeles will be spared the cauldron, with downtown expected to soar Saturday into the 90s, the hills around downtown into the 100s, and the San Fernando and San Gabriel valleys up to 105 degrees.
Parts of the Mojave desert in the Antelope Valley were expected to hit 111 degrees Saturday and Sunday before gradually cooling off through the week.
Only the beaches were expected to hold off into the upper 70s and 80s. Mountain cities, meanwhile, employed their cooler heights to beckon tourists.
"We are at least 20 to 30 degrees cooler here," said Dan McKernan, spokesman for Big Bear Lake. "It would behoove people to escape the heat."
With no rain forecast before Monday, downtown Los Angeles was poised to receive 5.85 inches since July 1, 2012 -- 39 percent of normal -- making it the sixth driest year in 135 years of measuring. With less than 3 inches of rain since January, it was the eighth driest January-to-June on record. The period usually accounts for 75 percent of SoCal rainfall.
"In January, the well went dry, and we were pumping dust," said Patzert, who noted that the Northern Sierra snowpack for January through June was lower than any time since record-keeping began in 1921. As a result, he said water districts across the region may be struggling.
Los Angeles has experienced an extended dry spell. Since the El Nino deluge ended in 1998, only four of the past 15 years have recorded higher rainfall than the normal 15.14 inches. More thirst may be in store for 2013-14.
"We could see another La Nina, the diva of drought," Patzert said. "So it could be dry all over again, "Before the large lady yodels, we may be talking the R word -- (water) rationing."
Staff Writer Canan Tasci contributed to this report