Major I-95 cities -- Philadelphia, Baltimore, Washington, D.C., and Richmond, Virginia -- could be impacted as heavy downpours could bring 2-3 inches of rainfall per hour over already saturated soils, which could easily cause flash flooding.

Millions across the Northeast and Mid-Atlantic remain under flash flood warnings early Tuesday as slow-moving summer storms bring heavy showers to the East Coast, impacting transportation and leaving people stranded in vehicles on waterlogged roads.