Tuesday Jan. 24, 0555 hours EST — A Coronal Mass Ejection (CME) is expected to hit Earth at about 0900 EST (1400 GMT) today, according to the NOAA Space Weather Prediction Center (SWPC).

UPDATE 0900 hours EST — The Northern Lights have lit up the skies above Scotland, northern England and northern parts of Ireland, reports AP.

The radiation storm has remained at the S3 (Strong) level, but should now be at or near its peak, and is expected to begin to decrease soon, NOAA says. The SWPC forecast is for Moderate level geomagnetic storming with higher levels possible.

Updates will be posted here or on Facebook.

A coronal mass ejection is a massive burst of solar wind, other light isotope plasma, and magnetic fields rising above the solar corona or being released into space.

When the ejection is directed towards the Earth and reaches it as an interplanetary CME, the shock wave of the traveling mass of solar energetic particles causes a geomagnetic storm that may disrupt the Earth’s magnetosphere. It can disrupt radio transmissions and cause damage to satellites and electrical transmission line facilities, resulting in potentially massive and long-lasting power outages

Characteristics of S3 (Strong) radiation storms (from NOAA):

• Biological: radiation hazard avoidance recommended for astronauts on EVA; passengers and crew in high-flying aircraft at high latitudes may be exposed to radiation risk.
• Satellite operations: single-event upsets, noise in imaging systems, and slight reduction of efficiency in solar panel are likely.
• Other systems: degraded HF radio propagation through the polar regions and navigation position errors likely.

This animation depicts results from a solar wind forecast model used at NOAA’s Space Weather Prediction Center, to predict when an event on the sun’s outer atmosphere (center) may reach Earth (right) and cause a geomagnetic storm: