Topband: weird propagation in the offing

[N7DF]

The interplanetary magnetic field has been south oriented for the last several hours (as of 0100Z Dec 10)  This opens magnetic portals which can permit charged particles from the sun to penetrate deep into the ionosphere activating propagation anamolies which may include some unusual top band openings 
 
The Bz field in this chart shows the part of the interplanetary magnetic field that affects the portals
 
http://www.swpc.noaa.gov/ace/MAG_24h.html
This presentation explains  magnetic portal and related studies underway

 http://www.youtube.com/watch?v=y3_vW5yrNek