AtDTDA (16) 434 +

[robinlandseadel at comcast.net]

Also noted while reading through the section of Tchitcherine's 
passage into what must be Kazakhistan:

          . . . often he'll come outside to find his morning skies 
          full of sheet lightning: gusting, glaring. Awful. The 
          ground shudders just below his hearing. It might be 
          the end of the world, except that it is a fairly average 
          day, for Central Asia. Pulse after heavenwide pulse. 
          GR [V339, B394, P344]

Further down on the page there's "Light pulses behind the clouds."
This all seems related to  the "heavenwide blast of light' in AtD.