National Weather Service bulletin: “A deep storm over the Mid-Atlantic Coast will move northward into Eastern Canada by Monday evening. The system will produce heavy rain over parts of the northern Mid-Atlantic Coast northward to New England. Therefore, the WPC has issued a Slight Risk of excessive rainfall over parts of the northern Mid-Atlantic Coast northward to New England through Tuesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable. In addition, the storm will produce showers and thunderstorms over the northern Mid-Atlantic Coast/southern New England Coast. The threat of heavy rain ends on Tuesday as the system moves farther into Canada.”
“Moreover, in the wake of the deep storm, upper-level energy over the Great Lakes/Ohio Valley moves eastward to the Northeast Coast by Tuesday evening. The energy and cold air will aid in creating lake-effect snow downwind of the Great Lakes and upslope snow over parts of the Northern/Central Appalachians on Monday into Wednesday. On Monday, the heaviest snow will be over parts of the Central Appalachians and southeast from Lake Michigan in Michigan and Indiana.”