Ramblings, rumblings, grumblings, and rambling grumbly rumblings.

Dan Henry gave what I thought was the definitive explanation of a microburst.

He described it as a potentially severe thunderstorm cell that falls apart and fall down, making everything else go BOOM!

So it's a cell that loses cohesion and falls straight to the ground in one swell foop, and all that energy goes sideways in all directions.