Temperatures as low as the 40s and 50s will cut across the Midwest and Northeast next week, but talk of a summer return of the "polar vortex" isn't entirely accurate, according to The Weather Channel. The Washington Post's Jason Samenow said the weather pattern bears a "haunting resemblance" to January's big freeze. The jet stream is dipping down farther south than usual over the eastern United States, just as it did back then, NBC News reports. But placing blame on the "polar vortex" is incorrect because the polar vortex exists in the stratosphere and not in the troposphere, the layer of atmosphere closer to Earth's surface where we experience our weather, . according to The Weather Channel.