Strong auroras are likely this weekend at high latitudes and possible at middle latitudes.

The huge sunspot group AR 1520, currently visible with no optical aid except a solar filter, let loose an X-class flare on Thursday, July 12th. The blast hurled a coronal mass ejection directly toward Earth, and the material is expected to arrive anywhere between 3:30 and 17:00 UT on July 14th. (That's any time between late Friday night and midday Saturday in North America).

2011 aurora

This aurora over Canada in 2011 was caused by a flare unleashed on March 7th, almost a year to the day of the powerful ejection heading toward Earth. Unlike the current X-class flare, the 2011 flare that triggered this aurora was only a middle-class flare.

NASA / Zoltan Kenwell

When the material hits Earth's magnetic field, it's likely to cause strong auroras at northern latitudes, including all of Canada and parts of the Upper Midwest. There's also a fair chance of auroras well south of there — conceivably as far south as Alabama.

Auroras are likely to continue for at least 24 hours after the solar particles arrive, so keep watching throughout the weekend. The combination of a favorable Moon phase and falling on a weekend makes this a particularly propitious opportunity.

See and the Geophysical Institute website for further information and ongoing updates.


You must be logged in to post a comment.