All through the spring, we in the eastern US lamented the long struggle to break through into the summer, as a standing trough remained entrenched over the eastern US, bringing significantly below normal temperatures to the area. The outlook maps looked a lot like this:
The Earth is tilted more directly at the sun, so the temperatures aren’t going to be sub-freezing, but the highs are going to be well off normal late this week. The west, as it was in the spring, will swelter, though now instead of an early, unnoticed summer, wildfires are going to be erupting across the region.
One difference between the patterns is that the jet flow isn’t as brisk, which means the jet stream is going to be a bit more pliable. Expect the cooler temperatures in the east to warm back up by the time next week begins.