LATURELL, OREGON – MAY 11: Katherine Richer (left) and her friend Andrea stare north … [+]
This week, Earth is in the path of multiple coronal mass ejections (CMEs) from the Sun, which could mean the northern and southern lights will once again illuminate a larger-than-normal portion of the planet's evening sky.
As of Sunday, the National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center predicted a 30% chance of a severe geomagnetic storm on Tuesday.
In layman's terms, this means that the massive amounts of charged plasma that have exploded from the Sun's outer layers in recent days are about to reach us and crash into the Earth's magnetic field. Such collisions can create so-called geomagnetic storms, causing aurorae and potential disruption of certain electronic equipment, including satellites and terrestrial power grid components.
The stronger the geomagnetic storm, the closer the auroras are to the equator, because all the energy pushes them beyond their normal homes near the poles.
If a G3 or severe storm occurs, the Northern Lights may be visible in states as far south as Oregon, Iowa, and Pennsylvania. The storm in May this year, which saw the most widespread aurora phenomenon in decades, was initially predicted to be a severe G3 storm, but everyone was surprised when it actually emerged as a G4 extreme event, with a range of Historic.
Forecast confidence this week is lower than in May, but still worth watching.
It was driven by a so-called “man-eating” coronal mass ejection, a coronal mass ejection that is overtaken by a faster such explosion on its way to Earth. The faster cloud of charged particles engulfs the slower cloud of charged particles, essentially merging with it.
The man-eating coronal mass ejection arriving on Tuesday is behind the severe geomagnetic storm warning, and there are other coronal mass ejections arriving later this week that could make things interesting on Wednesday and beyond.
Somewhat surprisingly, all of these CMEs are associated with moderate M-class solar flares. We could also see some action in the solar region this week or next, with last week unleashing the most powerful flare of this solar cycle, as well as a major coronal mass ejection that wasn't aimed in our direction.
All in all, it's going to be a week worth watching the skies. Check websites like Forbes or SWPC for the latest aurora forecast.
