09/27/11 Space Weather Storm

An early Autumn geomagnetic storm made it's way towards Earth yesterday. A Coronal Mass Ejection (CME) erupted from the Sun on Saturday morning, finally making it to Earth with a shock arrival around 8:37am ET Monday. It is currently at G2 (moderate) level, but is expected to reach up to G3 (strong level) on later today. 

Customers who may be affected, power grid operators, satellite operators, commercial airlines, etc., have been notified and are taking appropriate actions to minimize any adverse impacts. We can consider this a near miss because we’re only seeing the flanks of the CME. If this one had been headed directly at the Earth, then severe (G4) to extreme (G5) storming would have been likely. Also, the storm duration will be limited to about 12 hours, rather than the 24-36 hours that a direct hit could cause.  Here is an image of some northern lights making it down to northeast Minnesota.

In the past 24 hours, a slight decrease in the frequency of activity has been noted, but the region remains capable of emitting strong storms. Spot 1302, seen below, is still capable of producing more solar activity over the next 3-5 days, and will also happen to move into a more favorable position for Earth activity during that time as well. This particular sunspot has already produced two X-flares, one on September 22nd, and the other on the 24th.

According to NASA, "The biggest flares are known as "X-class flares" based on a classification system that divides solar flares according to their strength. The smallest ones are A-class, followed by B, C, M and X. The C-class and smaller flares are too weak to noticeably affect Earth. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that might endanger astronauts. M-class flares which are medium-sized events that can cause brief radio blackouts that usually only affect Earth's polar regions. There can also be minor radiation storms with an M-class flare that could endanger astronauts. Then, the X-class flares which are large sized, major events that can trigger planet-wide radio blackouts and long-lasting radiation storms. Similar to the Richter scale for earthquakes, each letter represents a 10-fold increase in energy output. So an X is ten times an M and 100 times a C. We will have to keep an eye on it over the next few days to see if it produces any more flares near Earth.