Skies on Monday were forecast to turn mostly sunny as a building ridge suppresses the marine layer. A stronger ridge was predicted to bring hot days Wednesday through Friday, the NWS said.
Forecasters' confidence was high that coastal highs will reach the 80s, valley highs will reach the 90s, and the lower deserts will eclipse 100 degrees Wednesday through Friday.
The heat wave was expected to end next weekend when a Pacific trough moves inland across Southern California. This was predicted to be followed by a more substantial West Coast trough that could transition to a much colder pattern with chances of precipitation early next week.
