Southern California’s first significant storm of the season brought weekend downpours that aided firefighters but caused ash, mud and debris to flow across streets in wildfire-burned areas.

AccuWeather's California Expert Ken Clark talks about the much-needed rain hitting California. Investors made a quick exit from a host of technology stocks from Tokyo to New York on Monday as the emergence of a low-cost Chinese artificial intelligence model challenged the dominance of current AI leaders such as Nvidia .