A geomagnetic storm watch has been issued for Sunday night through Monday, July 16-17, 2017. A large sunspot ejected energy in the past 24 hours, just as the sunspot was facing Earth. As this energy hits Earth, northern lights could develop.
The sunspot is larger in diameter than Earth. The geomagnetic energy ejected from the sunspot is called a Coronal Mass Ejection, or CME.
The geomagnetic storm watch is for a class G2 strength geomagnetic storm. NOAA’s Space Weather Prediction Center calls a G2 strength a moderate strength geomagnetic storm.
The more intense the energy is as it hits the earth, the greater the chance for northern lights to be visible farther south than normal.
How far south northern lights can be seen is pegged to a kP value. At this time, the forecast is for a kP value of 6. At that kP level, northern lights could be visible anywhere in Michigan, if skies are clear and you are under a very dark sky.
The kP value of 6 is predicted to begin Sunday afternoon and continue through at least Sunday night. Of course it has to be dark to see the northern lights.
Weather forecasting is difficult at times, and space weather is even more difficult. This doesn’t mean northern lights are a sure bet to be seen in Michigan. We will have to watch the space weather forecast and see if kP forecasts are increased.
Right now, if you have plans to be in a dark place in the northern half of Lower Michigan or anywhere in the U.P., keep the possible northern lights show on your mind.
As the energy from the coronal mass ejection gets closer, NOAA will fine tune the kP forecast. If we see the expected kP value go to a 7, we all better put ourselves in place to see a northern lights show.