What severe weather threats are currently impacting millions of Americans and how will conditions change over the weekend?

The United States is facing a complex multi-threat weather system affecting 35 million people under winter weather alerts. California continues dealing with lingering showers and Sierra Nevada snowfall, while mudslide risks persist in previously fire-damaged areas. The most significant concern is an intensifying system moving across the Plains toward the Northeast. This weekend system poses multiple hazards: heavy snow and ice accumulation of 4-6 inches (up to a foot in some areas) across New England and the Great Lakes, with dangerous quarter-inch ice accumulation possible. The southern portion of the storm brings severe thunderstorm threats including flooding and tornadoes. The multi-day event will impact travel significantly through Sunday evening. Officials emphasize this isn't just a Saturday event but will extend through Sunday, creating challenging conditions for both weekend travel and outdoor activities, requiring continued vigilance and safety precautions.