The National Mall gives an unobstructed view of a growing thunderstorm Wednesday. (Phil Yabut via Flickr)

A spinning weather system to our south, cold air at high altitudes, and fuel in the form of May sunshine conspired to trigger plentiful afternoon thunderstorms yesterday.

They developed in classic form, with the progressive growth of cumulus clouds – building into tower-like forms, i.e. cumulonimbus clouds.

The timelapse below, submitted by CWG Twitter follower Brendan Steidle, shows a great example of this storm growth process in Herndon, Va. yesterday afternoon:

While hit or miss, they were accompanied by downpours, lightning, gusty winds and small hail in some areas.

Here are some photos of the storminess from our Twitter feed: