Santa Ana winds set in motion by high pressure inland turned early spring into midsummer and sent Los Angeles and San Diego temperatures soaring to new April Fools' Day records Monday.
An afternoon high of 93 degrees broke the former Los Angeles Civic Center April 1 record of 92 degrees, set in 1967, and a reading of 87 at San Diego's Lindbergh Field broke the old mark of 83 degrees, set in 1971.
These record temperatures were not Southern California's highest for the day, however. That distinction went to Monrovia and Thermal, whose 94-degree readings made them the hottest spots in the nation, according to the Weather Service.
Other places were warm enough: Los Angeles' 93-degree high was matched by El Toro and San Gabriel; Long Beach, Yuma, Montebello and Palm Springs were just a degree behind with 92, closely followed by Pasadena and Santee with 91, and 90 recorded at Santa Ana, Torrance, Culver City and La Mesa.
What's more, National Weather Service forecasters said another record or two might be broken before the heat wave ends.
Stalled Pressure System
A large area of high atmospheric pressure is stalled over Utah and Nevada, meteorologists explained, and until it decides to move along, it will keep pushing hot--and dry--desert air toward the coast.
Relative humidity reached 43% in Los Angeles sometime during the cool hours before dawn Monday, but by mid-afternoon it was down to 11%, and forecasters said it should stay generally dry for a day or two, as long as the Santa Anas are blowing.
A high of 90 degrees was forecast for Los Angeles today, and the Weather Service said San Diego and other beach areas should enjoy highs in the lower 80s, with low desert temperatures about 5 degrees warmer, and north-to-northeast winds expected to rise to 25 m.p.h.
The forecast also called for highs in the mid-60s at most mountain resort altitudes, but warnings for east-to-northeast winds gusting to 60 m.p.h. at times were in effect for the mountains of San Diego County, and gusts from 30 to 40 m.p.h. were forecast for San Gabriel and the San Bernardino Mountains.
For thousands of students who flocked to the beaches and mountain and desert resort areas, it was an ideal start for the Easter vacation.
Clear Skies Forecast
Clear skies were forecast for the night and early morning hours in the Southland, and the Weather Service said east-to-northeast winds should be blowing 25 to 35 m.p.h. below most canyons and passes until further notice.
Nonetheless, the South Coast Air Quality Management District, while predicting good air in most parts of the Los Angeles Basin, said air might be unhealthful for sensitive people in Central Los Angeles, the San Gabriel and Pomona valleys and inland portions of Orange County.