I'd not even ever heard the term "collapsing thunderstorm" before today, when we were suddenly under a weather alert for such a thing - which caused extraordinary and surprisingly strong winds (indeed, downtown Santa Fe - thirteen miles away - was without power for three hours), and dust storms, and a very flat grey sky. The phrase seems to mean that each little thunderstorm cell goes off pop, as it were, on its own account - cold air meeting warm air in a whole series of fierce encounters, rather than all joining together as one front. I think, but there's not a whole lot of online glossing, and after another day dealing with basic physics (who knew that Jacques Cousteau called Harold Edgerton "Papa Flash"? I like that!) and Charles Peirce's theories of time, I'm not going to be delving too deeply into positive and negative charges. As it is, I find each little flash of lightning a nagging reminder that I should be writing, not checking the Weather Channel's radar maps.
As you can see, it was clearing by sunset. That dead tree - a casualty of drought over the last few years, and a graphic demonstration of the need for rain ... there were just a few minutes of it, in all that storminess.