Arctic air and lake-effect snow will continue to impact travel in the Upper Midwest and Northeast on Friday, with difficult conditions expected around the Great Lakes. Meanwhile, a developing storm will bring showers and potential thunderstorms to parts of the Florida Panhandle, Louisiana, Kentucky, and Missouri. Sporadic rain is forecast for the West Coast, with snow in the Sierra Nevada, Cascades, and Rockies. A significant Pacific storm is anticipated to bring heavy rain and snow to Northern California and the Sierra Nevada over the weekend.