The northern lights have a chance to shine over Canadian skies overnight tonight (Monday, Sept. 16) into tomorrow.

“We’re hoping that’s going to happen tonight,” said Robyn Fiori, a senior researcher and duty forecaster within the Canadian Hazards Information Service in a phone interview late Monday morning.

For it to happen, though, certain ducks have to align. Well, not ducks exactly, rather the right alignment of the magnetic field in coronal mass ejections (CMEs) that are on their way to Earth.

Fiori explained that the sun, which is in an active part of its regular 11-year cycle, has delivered three CMEs — “one that erupted on Sept. 13 and two that erupted on Sept. 14.”

Individually, each one would probably be expected to “deliver glancing blows to Earth.

“But we’re going to have probably a combination, or some combination, of these three, plus we have some high-speed streams from coronal holes.”

It’s that combination of activity, she said “that has caused us to issue a geomagnetic storm watch from noon Monday until noon Tuesday (Toronto time).”

“And, yes, there is a possibility that we might see some northern lights because of the arrival of those CMEs and those high-speed streams from the coronal holes.”

It’s all going to depend on, though, “what the magnetic field looks like when it comes along with those coronal mass ejections.

“If it (the magnetic field) points northward we’re not likely to see anything, but if it points southward then we are likely to see something,” she said.

“That’s why we saw quite a bit of activity back in May earlier this year because we had a very strong southward magnetic field so hopefully we’ll get a little bit of the same and we’ll have the chance to view the northern lights again.”

As to whether the northern lights show will be a go tonight, she said scientists “don’t get an accurate picture of what the magnetic field’s going to look like until it’s about half an hour to an hour away from reaching the Earth, and that’s at a point we call the Lagrange point,” she said.

At that point, she said there’s a satellite there called DSCOVR (Deep Space Climate Observatory) “that’s observing that solar wind and that solar magnetic field, and as soon as we can see that then we’ll have an idea what’s going on.”

After that, she reiterated, it “takes about 30 to 60 minutes to reach the earth and then we’ll have impacts and then that can lead to the northern lights which can last for several hours after the CME arrives.”

The Environment Canada forecast for much of southern and eastern Ontario tonight would be conducive to viewing the northern lights (as well as other wonders of the heavens) because of a large high pressure system that is producing sunny (and warm) days and clear nights.

“I’ve got my fingers crossed that I seem something,” said the scientist speaking from Ottawa.

While the northern lights are a rare but welcome treat for many stargazers in southern Canada, the effects of these CMEs, unfortunately, do more than just cause pretty lights.

“Any time we have a change in our magnetic field which we can see with the arrival of these CMEs, we can see currents being induced into long conductors like power systems … Along with the northern lights, we see particles being injected into our upper atmosphere, called the ionosphere, that can impact systems like radio communications, like GNSS (global navigation satellite system), she said.