The storm took on the appearance of a massive UFO, sometimes called a “mothership” because of its resemblance of a giant flying saucer streaking across the sky. We often see “mothership” photos from storm chasers in the Plains, but not so much in Fairfax, Va.
The storm unleashed damaging wind gusts that downed trees and produced hail up to one inch in diameter.
How did it develop?
To get storm clouds this high, what’s needed is a vigorous cloud updraft or multiple updrafts, which are fed by highly buoyant air from near the surface. With Thursday’s sun-baked temperatures in the low 90s and copious humidity, the atmosphere became quite unstable and was amenable to “overturning” through a very deep layer. There was plentiful buoyant energy stored up and then released in the atmosphere — about 40 to 50 percent more than what we typically experience on “ordinary” thunderstorm days.
The problem with a small, isolated storm cell is that relatively drier and cooler air from mid-levels of the atmosphere can mix in from the sides, diluting some of that buoyancy that tries to make the cloud rise so high (we meteorologists call this process “entrainment”). But the enormous thunderstorm complex that developed over Northern Virginia was effectively a giant cylinder of moisture-laden air that shielded its core updrafts from buoyancy-robbing, drier air. Those interior updrafts pushed cloud tops to limits not often seen in this area.
Below see amazing views of the storm from all across the region:
(Kevin Ambrose contributed to this post.)