The weekend deluge was only the beginning.
Several more onslaughts of heavy rain are expected in the East this week, especially in the mid-Atlantic region, leading to "potentially dangerous, even life-threatening flooding," the National Weather Service warned.
Flood watches and warnings have been posted from Pennsylvania to North Carolina. At least 10 million people are under flood watches or warnings.
Additional rainfall totals of 5-10 inches are possible somewhere in the central Appalachian Mountains to the coasts of the mid-Atlantic and North Carolina, AccuWeather meteorologist Kristina Pydynowski said.
Over the weekend, record-setting rainfall triggered flash flooding in Virginia and Maryland, stranding vehicles and prompting water rescues and road closures. Saturday was one of the wettest July days ever recorded in both Washington and Baltimore.
“A cycle of daily rounds of showers and thunderstorms is likely to repeat on most days this week,” AccuWeather Meteorologist Kyle Elliott said.
The heavy rain could also trigger mudslides in the mountains, cause trees to topple over due to the wet ground and wreck travel havoc on roads and at airports.
The reason for the soaking weather pattern is a powerful plunge of the jet stream – by July standards – which has carved into the East and will sit in place for the next several days, according to weather.com.
This pattern is tapping a plume of deep, tropical moisture from the Gulf of Mexico and Caribbean Sea into the Eastern Seaboard around high pressure in the Atlantic, weather.com said.
While the East battles the raindrops, heat remains in place across the southern Plains, lower Mississippi Valley, and much of the Southwest and far western United States. Temperatures will soar above 110 degrees in the Southwest and over 100 degrees in Texas, the weather service said.
The heat will be extreme even in normally torrid Death Valley, where daytime highs this week will soar in the mid-120s. The nighttime low temperature there will hover around 100 degrees each day.
The heat will also set the stage for a heightened risk of wildfires in the Southwest, including Southern California, this week, AccuWeather warned.