OK, I had to Google it. Turns out radio blackouts with satellite comm systems to happen simultaneous with the Flare being observed. The intense EM radiation basically ionizes part of the ionosohere, causing the radio signals to be absorbed. So we WOULD expect potential disruption to comms as soon as the Flare was observed.
OK, I had to Google it. Turns out radio blackouts with satellite comm systems to happen simultaneous with the Flare being observed. The intense EM radiation basically ionizes part of the ionosohere, causing the radio signals to be absorbed. So we WOULD expect potential disruption to comms as soon as the Flare was observed.
Source