Geomagnetic storm could bring aurora viewing in the Maritimes Thursday night

A photo of the aurora borealis courtesy of Brandy Flynn-Dolliver taken near Rawdon, N.S., on April 23, 2023.

The Space Weather Prediction Center of the United States is predicting the likely occurrence of a strong geomagnetic storm Thursday night, creating an aurora active enough it could be spotted in the Maritimes.

A geomagnetic storm is the interaction of the Earth’s magnetic field with highly energized particles emitted from the Sun during a coronal mass ejection.

The conditions can interfere with radio frequencies, GPS systems, and in some cases cause power system issues. It also produces spectacular aurora borealis displays that can often been seen at latitudes much further south than typical.

The Kp index forecast for Thursday night by the Space Weather Prediction Center of the U.S.

One of the ways the strength of a geomagnetic storm is rated is through the Kp-index. The Kp-index rates 0-9, with 0 being calm, minor geomagnetic storm conditions staring at 5, and strong geomagnetic storm conditions starting at 7.

The Kp-index is forecast by the organization to reach 7 around 2 a.m. Friday Atlantic time. In the past, observed Kp-index values of 5 to 7+ have been associated with a visible aurora display in the Maritimes. For Thursday night, it appears the best time to try and catch a glimpse of the aurora is generally between midnight and dawn.

Partly cloudy with chilly temperatures forecast for Thursday night and the pre-dawn hours of Friday.

The sky conditions during that time won’t be perfectly clear. Some broken cloud is expected to be over the region Thursday night. Breaks of clear night sky look most likely for southern and eastern areas of New Brunswick, Prince Edward Island, and mainland Nova Scotia. It will be a chilly night with low temperatures ranging a few degrees below to a few degrees above freezing.

To give yourself the best chance of viewing you would want to go to a location away from city and town lights. Look towards the north and lower on the horizon. Have patience and realize that, even if visible, the aurora may be on the fainter side. Like terrestrial weather, space weather can throw a curve ball at predictions. I’ve see situations in the past when a stronger geomagnetic storm was forecast, but failed to materialize into a visible aurora display.