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).

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 Spaceweather.com and the Geophysical Institute website for further information and ongoing updates.