Flash flooding threatens Mid-Atlantic, heat scorches many states

Weather warnings are in place for millions of Americans this week as storms and heavy rain pummel the mid-Atlantic states and the Carolinas. A heat wave is also intensifying and expanding.

More than 100 million people are expected to fall under some sort of heat watch or warning this week, while millions more are forecast to be cautioned about their risks for heavy rain or potential flash flooding, according to the National Oceanic and Atmospheric Administration.

Tropical Storm Bertha is not expected to bring intense rain to the Gulf Coast but the system is helping to push tropical moisture into the eastern United States.

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That moisture is colliding with a strong cold front to generate flash flood warnings and repeated bouts of storms through Friday for a region stretching from Kentucky and West Virginia, eastward to New Jersey and as far south as the Carolinas, said Bryan Jackson with NOAA's National Weather Service Weather Prediction Center.

Days of heavy rain possible

It's going to be "quite a rainfall event for the mid-Atlantic and the Carolinas over the next few days," Jackson said. The front is expected to sag southward slowly during the week, soaking and potentially causing flash flooding in the Hampton Roads area of Virginia, including Norfolk and Virginia Beach, on July 22 before shifting southward into the Carolinas on July 23-24.

Rainfall is forecast to range from 2 to 5 inches across the larger region, Jackson said, but depending on how things set up in the atmosphere, there's a potential for up to 8 inches of rain in the Hampton Roads area and over eastern North Carolina. He added the phenomenon of heavy rain when a tropical plume of moisture encounters a strong cold front is very well documented in previous rain events.

Record-breaking heat forecast

As the week progresses, a wave of "dangerous heat" is expected to expand from the Gulf Coast across the Central U.S. and then westward by July 27, the weather prediction center said on July 21. Several consecutive days of hazardous heat are expected because of the combination of afternoon high temperatures and warm overnight lows, with heat indexes – what the heat feels like in the shade – reaching as high as 115 degrees in some locations. The overnight lows may be record-breaking, the prediction center said, and cause "accumulated heat stress."

The weather service is urging people to limit their outdoor activities during the hottest afternoon hours and to stay hydrated.

A high risk of extreme heat covers the Central and Southern Plains and lower Mississippi Valley on July 29-30. Beyond that, NOAA forecasters also see a "high risk" for a heat dome over Texas and the southern Plains into early August.

How can you help prevent heat-related illness and death?

The Centers for Disease Control and Prevention and the weather service offer the following tips:

• Know what the temperature is going to be where you are, which you can find by entering your zip code on a CDC website.
• Familiarize yourself with the symptoms of heat-related illnesses.
• Stay hydrated by drinking fluids.
• Avoid outside activity during the afternoon hours.
• Check on neighbors, children and the elderly.
• Watch for signs of heat distress in yourself and others.
• Don't use a fan if the temperature in a room is more than 90 degrees.

Dinah Voyles Pulver, a national correspondent for USA TODAY, writes about violent weather, climate change and other news. Reach her at [email protected] or @dinahvp on Bluesky or X or dinahvp.77 on Signal.

This article originally appeared on USA TODAY: Flash flooding threatens Mid-Atlantic, heat scorches many states