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GLANCING-BLOW CME EXPECTED THIS WEEK:
A magnetic filament on the sun erupted during the late hours of Nov. 15th, hurling inky-black fragments of itself into space. Shortly thereafter, a CME was observed racing away from the sun:
Storm track models from NOAA suggest that the CME will deliver a glancing blow to Earth’s magnetic field on Nov. 18th or 19th. There is a 70% chance of polar geomagnetic storms when the CME arrives.
Actually, the arrival of the CME could be the second strike. A co-rotating interaction region (CIR) is also expected to hit Earth’s magnetic field on Nov. 18th. CIRs are transition zones between fast- and slow-moving solar wind streams. Solar wind plasma piles up in these regions, producing density gradients and shock waves that do a good job of sparking auroras.
The double impact, CIR followed by CME, could produce a G1 or G2-class geomagnetic storm and bright auroras around the Arctic Circle. Observers in northern-tier US states from Maine to Washington should be alert for colorful lights in the midnight sky
