As cooler air drives into the sea of heat and humidity in the East, locally powerful thunderstorms will continue to develop into this evening.
Relief is coming for those with heat-sensitive health problems, but big thunderstorms are marking the transition.
There is a risk of strong to perhaps damaging thunderstorms this afternoon and evening along the I-95 corridor from Richmond to Washington, D.C., Baltimore, Wilmington, Philadelphia, Trenton, New York City, Hartford, Providence and Boston.
While the storms will not be severe in every neighborhood, they can bring a brief period of damaging wind gusts and blinding downpours to many locations.
A few communities can be hit with downed trees and power outages, frequent lightning strikes, urban flooding and hail.
Much cooler and drier air will work in aloft, while the air remains hot and humid at the surface into this evening.
This setup produces an unstable atmosphere that can be made acute by the approach of the cooler air at the surface.
Folks spending time outdoors into this evening should keep an eye out for rapidly changing weather conditions and seek shelter in a building away from windows as storms approach.
In addition to the heat, the approach of the storms could lead to delays at area airports and poor visibility on the highways, due to blinding downpours.
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Dry weather across the western half of the country continues to spark wildfires, especially across Utah and the Northwest.
AccuWeather.com meteorologists are monitoring an area of thunderstorms near Palau for potential tropical development.
Strong and severe thunderstorms from Canada and the northern Plains will shift into the Midwest and Ohio Valley in time for the weekend.
Former Typhoon Matmo continues to wreak havoc across portions of China.
Stormy weather will be the theme for the weekend across the Midwest and Ohio Valley with several chances for severe thunderstorms.
Rowan, NC (1996)
4" of rain in 45 minutes.
Southern California (1996)
7-10 foot swells on the beaches from a powerful storm south of Tahiti. Life guards had to make more than 500 rescues due to the rough surf.
Los Angeles, CA (1891)
Heat wave; 109 degrees.