The Northern Lights could appear much further south tonight, tomorrow and Friday, perhaps even near you.
A geomagnetic storm is brewing and it could form auroras over parts of Canada and the northern parts of the continental United States. Oregon, Iowa, Pennsylvania, and New York could all see a shimmering sky after sunset. It is the product of recent rare and unusual weather in space.
NOAAs Space Weather Forecast Center (yes, that’s a thing) issued a geomagnetic storm watch from Aug. 17 to Aug. 19 “due to coronal high-velocity flow (CH HSS) and coronal mass ejection (CME) influences” with the potential to escalate to G3 conditions.
Okay, let’s unpack that now.
This all started a few days ago, 93 million miles away, on the sun. A coronal mass ejection is a large burst of magnetized plasma from the sun’s corona, the outermost layer. Scientists recently discovered two of these CMEs erupting on the sun and heading for Earth. They are expected on August 18.
The two eruptions can combine along the way, creating a geomagnetic storm that reaches G3 or “strong” levels. That means it can create auroras not only at the poles, but also closer to the equator than normal.
AURORA FORECAST: Tonight’s aurorae forecast for the potentially impending moderate/strong geomagnetic storm shows generally cloudy conditions in the northeast and better than average conditions for parts of Michigan, the Rocky Mountain West, the Pacific Northwest. Details below: pic.twitter.com/OebQXDr1oU
— Space Weather Watch (@spacewxwatch) August 17, 2022
Auroras form when high-energy particles from the sun collide with the Earth’s atmosphere. These particles excite the gases in the air and make them glow, similar to how neon lights work. Auroras are one of the few ways we can see space weather from the ground, and while they’re usually confined to the poles, enough excitement from the sun can create auroras much further away.
But before the CMEs arrive here tomorrow, a high-velocity current with a coronal hole is expected to arrive tonight and drive a G1, or “minor,” geomagnetic storm. A coronal hole is a cooler region in the sun’s corona that can generate high velocities solar wind charged particles and scatter them across the solar system. High-velocity currents in coronal holes can also generate auroras on Earth.
Forecasters expect G2 or “moderate” storm activity to continue on Aug. 19.
NOAA warns that geomagnetic storms can be disruptive if they become severe. Geomagnetic storms can impact infrastructure in orbit and on the surface, potentially disrupting communications, the power grid, navigation, radio and satellite activities. NOAA press release.
The upcoming storms are not expected to cause many technical problems. Still, it might be a good opportunity to put all your electronics away for a few hours and just look up. You might just see the sky light up.