High likelihood of seeing northern lights in Calgary, aurora ...

National Oceanic and Atmospheric Administration has issued a rare severe geomagnetic storm watch — its first in 20 years — after the recent eruption of strong solar flares.

Published May 10, 2024  •  Last updated 2 minutes ago  •  2 minute read

Aurora borealis brightens the night sky between Acme and Three Hills, Alberta, on Thursday December 31, 2015. Mike Drew/Postmedia file

Heads up: If the sky stays clear Friday night, there’s a high likelihood of seeing northern lights in Calgary and all of Western Canada, according to space weather forecasters.

The Space Weather Prediction Centre at the U.S. National Oceanic and Atmospheric Administration has issued a rare severe geomagnetic storm watch — its first in 20 years — after a large quantity of particles recently expelled from the sun were expected to reach Earth Friday night into Saturday.

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The watch starts Friday and lasts all weekend.

NOAA said the sun produced strong solar flares beginning Wednesday, resulting in five outbursts of plasma. Each eruption — known as a coronal mass ejection — can contain billions of tons of solar plasma.

Northern lights are one visible effect of such solar storms and it’s expected all of Western Canada and much of the east of the country could get a front-row seat for a celestial light show thanks to a promising aurora forecast, local conditions permitting.

It’s expected Calgary will have a clearing sky with a few clouds Friday night, according to the latest weather forecast issued by Environment Canada.

NOAA is calling this an unusual event, pointing out that the flares seem to be associated with a sunspot that’s 16 times the diameter of Earth.

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Solar flares are also capable of disrupting satellites in orbit and power grids on Earth.

G4 solar storms, such as the one being currently observed, can wreak havoc on technology, causing widespread voltage control problems, radio blackouts and more frequent issues for GPS satellites.

An extreme geomagnetic storm in 2003 took out power in Sweden and damaged power transformers in South Africa. A similar event in 1989 took down the power grid in Quebec.

While trouble for electrical utilities is possible during such storms, a spokesperson from the Alberta Electric System Operator recently told Postmedia this is less of an issue in Alberta, although they are monitored as there is a small chance solar storms can impact the grid.

“We are less susceptible here in Alberta than in central Canada. In Quebec or Ontario, there is a higher chance of problems due to induced ground current on transformers, because they sit on the Canadian Shield,” AESO said.

NOAA already has alerted operators of power plants and spacecraft in orbit to take precautions.

“As far as the worst situation expected here at Earth, that’s tough to say and I wouldn’t want to speculate on that,” said NOAA space weather forecaster Shawn Dahl. “However, severe level is pretty extraordinary. It’s a very rare event to happen.”

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The most intense solar storm in recorded history, in 1859, prompted auroras in central America and possibly even Hawaii. “That’s an extreme-level event,” Dahl said. “We are not anticipating that” but it could come close.

The sun is approaching the top end of its 11-year activity cycle, called solar maximum, and it’s expected northern lights could become more frequent across Canada and potentially in the northern half of the continental United States.

“Although predicting these events beyond a few days can be challenging, we can confidently say that with solar maximum approaching, more captivating displays of auroras are undoubtedly on their way,” Bryan Brasher, project manager of the Space Weather Prediction Center at the National Oceanic and Atmospheric Administration, told Postmedia in November.

With files from Postmedia and The Associated Press

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