Historical data from the previous twenty-four solar cycles shows a strong correlation between how fast a solar cycle rises and its maximum amplitude. Big cycles rise faster than small cycles.

With 10 months of smoothed sunspot number data so far, the above plot shows Cycle 25 rising a bit faster than Cycle 24. But I think it’s still too early to conclude with any confidence where Cycle 25 is headed.

ARRL DX CW 2012 - Which 10M Path

Is the ionosphere really lower

Grand Solar Minima

Butterfly Diagrams and Solar Minimum

A Look at All Twenty Three Solar Cycles

The Robust Equatorial Ionosphere