Earlier today, the Sun fired the biggest solar flare we've seen thus far in our current solar cycle. With an X-ray magnitude of X6.9, this flare was three times larger than the previous titleholder, a X2.2 from mid-February.
Today's flare wasn't aimed at Earth, so it shouldn't affect our communications technologies. Just how powerful was today's flare? Explains NASA:
The biggest flares are known as "X-class flares" based on a classification system that divides solar flares according to their strength. The smallest ones are A-class (near background levels), followed by B, C, M and X. Similar to the Richter scale for earthquakes, each letter represents a 10-fold increase in energy output. So an X is ten times an M and 100 times a C. Within each letter class there is a finer scale from 1 to 9.
C-class and smaller flares are too weak to noticeably affect Earth. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that might endanger astronauts.