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.
Although spring may be in full swing, more than one-third of the Great Lakes remains covered in ice.
Rain will return to Atlanta Friday and Saturday as a storm system moves through to the Southeast.
To wrap up the workweek, more clouds will move into Cleveland Friday along with lower temperatures.
A low pressure system is set to deliver heavy rain to parts of the Southeast Friday and Saturday, bringing the risk of flooding to the area.
A recap on a small, but potent April snowstorm that hit Minnesota and Wisconsin this week.
Following some rain showers this Saturday, drier weather is in store for Boston by Monday to kick off the 118th annual Boston Marathon.
San Francisco, CA (1906)
Earthquake and fire. Infrequent easterly wind drove flames westward through the city rather than confining them to the downtown harbor area.
Wyoming, South Dakota (1966)
24" of snow and blizzard conditions in South Dakota. 20" of snow at Lander, Wyoming.
Rapid City, SD (1970)
22" of snow (17th-18th) -- 24-hour record.