Heat wave pushes Pittsburgh toward 100 degrees

The big picture: A "heat dome" is hovering over much of the eastern half of the U.S., trapping warm air over the area for an extended period.

Zoom in: Local highs push above 90s starting Tuesday and could rise to near 100 degrees by Thursday or Friday, according to the weather service.

• It will feel even hotter than that due to the high humidity.
• Thunderstorm chances arrive Friday and will linger through the weekend and could impact Fourth of July celebrations.

State of play: The city of Pittsburgh activated its five cooling centers across the city to give public access to air conditioning to those who need it.

• Search for other cooling centers outside the city here.

What's next: Temperatures above 90 degrees are forecast through Sunday. It's too soon to tell when exactly the heat dome will end.