These blackouts generally affect communications in the HF (high frequency)
range. This means that frequencies below about 30-40Mhz will be affected.
The reason is that the F layers of the ionosphere are used to "skip"
signals for long distance communications. The solar storms cause massive
disturbances in the ionosphere which cause this "skip" effect to shut
down. It is actually impressive to listen to by virtue of the total
absence of normal noise, or any other signal, on these bands of
frequencies. These frequencies are used, on occasion, for extremely low
speed commercial/military digital communications (110 baud).
This should have no effect on us. The R3 classification will shut down HF
radio communications for a bit, but the G2 geomagnetic classification is
not too bad and should not affect the power grids. Severe geomagnetic
storms can shift the magnetic poles by many degrees.
There are many places to get more information about sunspots. Being an
amateur radio operator who likes HF communications, I have a bit of an
interest in the topic.
The most succinct monitoring and information site I have found is run by a
group of short wave listeners in the Netherlands:
http://www.dxlc.com/solar/
Many of the measurements used are taken in Boulder (Boulder K index). Nasa
usually has some great photos of the big CMEs/Flares
