LOS ANGELES (CNS) - The second Southland heat wave of the summer went into a second day today, pushing temperatures into the triple digits in some L.A. County communities, prompting the National Weather Service to issue a heat advisory for the San Fernando and Santa Clarita valleys.
The heat advisory, indicating an expectation that hot temperatures and high humidity will combine to create a situation in which heat illnesses are possible, will remain in effect until 9 p.m. Wednesday. Temperatures in those areas are expected to range around 103 degrees, according to the NWS.
``The combination of very high temperatures and humidity creates a dangerous situation in which heat illnesses are possible,'' according to the NWS. ``Temperatures inside vehicles, even if the windows are partially open, can quickly rise to life-threatening levels.''
Forecasters urged the public to ``drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.''
The National Weather Service said the heat wave, which is accompanied by monsoonal moisture out of Mexico, meaning it may feel even hotter than what the thermometer shows, will persist through the weekend. Forecasters warned that this week's weather brings the potential of heat-related illnesses, especially for the homeless, the elderly, infants, and anyone participating in outdoor activities.
Long Beach reached 96 degrees on Tuesday, breaking the record for that date of 94 degrees, set in 1974.
A number of communities hit triple digits, including Pasadena, Van Nuys, Chatsworth, Woodland Hills and Saugus.
The heat wave results from high pressure over the nation's Four Corners region, said NWS meteorologist Curt Kaplan. It has no meteorological connection to the hot weather on the East Coast.
Over the next few days, air circulating clockwise will pick up moisture from Mexico, including Baja California, Kaplan said. There's no expectation of flash flooding, he said, but there could be an elevated danger of fire amid the dryness at lower elevations if thunderstorms develop and generate lightning, including dry lightning.
There is a slight chance of afternoon thunderstorms over the mountains through Wednesday, according to an NWS statement.
A slight cooling trend will get underway toward week's end.
NWS forecasters said that, to cope with the weather, area residents should drink plenty of water, wear light-colored, lightweight clothing, stay out of the midday sun, exercise only early or late in the day, check on elderly friends and neighbors, provide shade and water for livestock and pets.