The coronal mass ejection from a large solar flare is expected to strike planet earth tonight or tomorrow, possibly affecting electronics and boosting polar auroras.

The website Spaceweather.com says the flare has the potential to trigger significant geomagnetic activity when it reaches Earth's magnetic field.

The flare is expected to hit late tonight or early tomorrow.

Two solar storm clouds were propelled in earth's explosions in the magnetic canopy of sunspot AR2158 on September 9 and 10. Strong geomagnetic storms are possible on tonight and tomorrow as a result of the consecutive impacts. Sky watchers, even those at mid-latitudes, should be alert for auroras in the nights ahead.

The origin is Sunspot AR2158, which erupted on September 10 at 5.46am NZ time, producing an X1.6-class solar flare. A flash of ultraviolet radiation from the explosion ionized the upper layers of Earth's atmosphere, disturbing high frequency radio communications for more than an hour. The coronal mass ejection from the flare is heading directly toward earth.

Radio emissions from shock waves at the leading edge of the flare show the speed through the sun's atmosphere was initially as high as 3,750 km/s. By the time it left the sun's atmosphere, the cloud had decelerated to 1400 km/s, making it a ‘fairly typical CME' instead of a ‘super CME' as the initial higher speed suggested.