http://socalxc.blogspot.com.au/2013/11/catching-up.html

The southern cloud street had filled in from when I first arrived
at Lockwood. Despite that, from my angle near base, the cloud line didn’t look
very wide. The shadows on the ground should have been a tell, but at the time I
thought most of the darkness was caused by the stuff billowing up above Frazier.
The fact that there was nothing but blue skies on the other side of the clouds
was probably the main factor for me continuing on. That, and the fact that I’ve
seen these conditions before near Frazier, and made it through to the other side
without issue.

As I left the lift near Grade to go on my glide I thought I was in perfect
position. By the time that I would reach the last line of clouds I would lose
enough altitude to scoot underneath them. If I did encounter any lift I would
already be close enough to the other side to avoid any trouble. Of course, that
didn’t happen; if anything I gained altitude.