"Heat wave so big you can see it from space" is not a weather forecast manufactured as a rap line, it's reality. If you're sweating through this heat wave (which you most likely are), the image above allows you to visualize its abusive strength and reach. The heat wave is so large, so massive, that it's visible from space.
The aforementioned image, which shows a clear space above the Ohio Valley, was captured by the GOES East satellite at 12:45 p.m. on Jul. 15. This is the center of the heat wave, which has residents of the East Coast roasting in temperatures in the 90s that feel like triple digits.
NASA offered an in-depth explanation of the hot pocket and its movement:
A very anomalous weather pattern is in place over the U.S. for mid-July. Trapped between an upper level ridge centered over the Ohio Valley and the closed upper level low over the Texas/Oklahoma border, atypical hot, muggy air is stifling a broad swath of the eastern U.S. The closed low is expected to drift west toward New Mexico bringing heavy, localized rain to some areas and temperatures running 10-20 degrees below mid-July averages. Across the east, temperatures will warm well into the 90s and stay there through the week. (NOAA)
Pray for rain and cooler temperatures.