G4: " Induced pipeline currents affect preventive measures, HF radio propagation sporadic..."
G5: " Pipeline currents can reach hundreds of amps, HF (high frequency) radio propagation may be impossible in many areas for one to two days..."
Sam Altman has entered an agreement to acquire all future G4 and G5 energy
"Cool! What's G13 do?" - Bill Hicks
Looks like G5 is the highest level and the scale system is used by NOAA.
Waiting until it's like a G6, Like a G6
Now I'm feelin' so fly like a G6