After waking up to a couple sprinkles in DC, and my workshop participants worrying and wanting to cancel the class, I had us press forward. As a general rule, I won't cancel unless it's calling for constant pounding rain; many of you understand the photographic opportunities related to weather. Soon after 530, clouds began to break and showed a small window to the moon. Occasional drops and lightning in the high clouds quickly gave way as the horizon began to glow.
As the sun rose, a few crepusculars danced amongst the orange, and slight purples and blues.
Hope it showed the participants that it pays to get out there and shoot, even when it looks like "poor" weather.
Thanks for your comments!
Nikon D800, Nikon 14-24, CPL (very slight), f/9, ISO 50, 2 shot blend for DR