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.
After an earthquake hit in the area, the Bardarbunga volcano erupted Friday in Iceland, causing a temporary no-fly order.
It's been a tumultuous week on both the East and West coasts as two hurricanes induced rough surf and a high risk for rip currents.
After a brief cooldown late this week, very warm and humid air will bounce back during the Labor Day weekend.
A disturbance over the Gulf of Mexico will deliver rain to the coast of Texas on Friday before expanding over the lower Mississippi Valley this weekend.
A great white shark was spotted at Duxbury Beach in Massachusetts earlier this week, forcing the evacuation of the water.
While Marie will stay well offshore from Los Angeles, it will continue to produce dangerous surf along many Southern California beaches through Friday.
New England (1816)
"Year in which there was no summer", otherwise known to weather historians as "1800 and frozen to death" killing frost once again damages sparse corn corp in northern New England...loss of this and other crops led to severe famine in much of New England that winter...and helped spur western migration in spring of 1817.
New England (1965)
A total of 2.5 inches of snow on top of Mt. Washington set an August record. Vermont had a reading of only 25 degrees, while Nantucket had a chilly 39 degrees. Earliest freeze on record at many stations.
Houston, TX (1980)
2.23 inches of rain fell in less than 1 hour. Streets were flooded in the downtown district and a tornado touched down briefly west of Houston at Sealy, TX.