'Really good show': Northern Lights could return to the Foothills –


If you missed the spectacular display of the Northern Lights earlier this month, there's a chance you'll see them again soon.

A sunspot that triggered a series of solar flares on May 10 and 11 — the largest in nearly two decades — turned back toward Earth this week, unleashing another powerful but less intense flare.

This means that the Northern Lights could return to the skies above the foothills on Friday night.

The U.S. National Oceanic and Atmospheric Administration (NOAA), which rates geomagnetic storms on a five-point scale, is forecasting a moderate Category G2 storm that will peak on Friday, while a severe Category G4 storm will hit in early May.

While the show may not be as intense as it was then, Roland Dechesne of the Calgary Chapter of the Royal Astronomical Society said there is still a chance for an impressive show.

“There are predictions with a probability of up to 40 percent for an all-sky or overhead event,” he said.

When asked how much northern lights will be visible in the foothills, Dechesne could not give a clear answer because it is incredibly difficult to predict the aurora.

He said the biggest challenge is determining the polarity of the auroras, i.e. whether they are moving toward the North or South Pole.

“Currently, the magnetic field coming towards us is pointing south, which is good because it is not deflected by the magnetic field of our Earth. If it stays that way, we can expect a really great show tonight,”

The NOAA forecast shows that the probability of seeing the Northern Lights is low along the route from Vancouver through Winnipeg to Thunder Bay, Ontario, but the probability is higher in the northern parts of the provinces and territories.

Still, Deschene believes the aurora can be seen in the Foothills and other parts of southern Alberta. The best time to look at the sky can also vary, Deschene said.

With that in mind, the best advice if you want to see a shimmering, glittering show is to get out of town and plan to stay as long as possible.

“You never know when little side storms will come along and really liven up the show,” said Dechesne.

In an email, NOAA said that as the days get longer, the window for viewing the aurora is shrinking, so the best time to view the aurora is anywhere from 11:30 p.m. to 2 a.m. or later.

For more details on the aurora forecast, visit the NOAA website.

With files from The Canadian Press