The USAF Civil Air Patrol will be conducting a nationwide exercise this weekend on their communication frequencies.
I found this item on the Colorado CAP Facebook page:
"The national
HF communications exercise, Constant Watch 13, is scheduled to
run
continuously from 2200Z 6 Dec to 2200Z 8 Dec."
I have just posted a new reference page here on the Milcom MP devoted to monitoring the CAP. 73 and good hunting.