Northern lights put on a show across B.C.

Like skywatchers across Canada, B.C. residents were treated to a dazzling display late Friday night and early Saturday morning.

Viewers shared dozens of stunning images of the northern lights, also known as aurora borealis, with CTV News on Saturday.

• IN PICTURES: Aurora borealis dazzles over B.C. 

The lights were visible across much of North America Friday night amid a strong geomagnetic storm caused by coronal mass ejections from the sun.

The U.S. National Oceanic and Atmospheric Administration issued a G4-level geomagnetic storm watch Thursday, the first one it has issued at that level since 2005. NOAA's scale goes from G1 to G5.

Coronal mass ejections are explosions of plasma and magnetic fields from the sun's corona. They cause geomagnetic storms when they are directed at Earth.

At least five Earth-directed flares linked to coronal mass ejections are expected to arrive as early as midday Friday and persist through Sunday, the U.S. weather agency said.

Auroras are sparked by the sun's energy and electrically-charged particles in the Earth's magnetic field. They generally present in a milky green colour, but viewers' photos captured overnight show brilliant pinks and purples as well.

With files from CTVNews.ca's Christl Dabu and CTV National News's Paul Hollingsworth