Aha! Found the article about Challenger Gray's comments released
today. Here's the main reason (from the article):
From 1995 to 2002, there were 36% more job cuts announced between September and January than there were between May and August.
So, in short, its just the nature of the economy to lay off more people after Labor Day. So if you thought the first half the year was tearing a hole in your pants, you might want to get some extra stiching put in for the 2nd half.
Okay, great! Good get. So it's not so much that he's seeing a systemic downturn, it's seasonal.