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GRAND RAPIDS, Mich. (WOOD) — A geomagnetic storm is set to slam into earth this weekend, and it may be strong enough for parts of West Michigan to see it. 

A KP Index of 4 is needed for the northern lights to be seen in northern parts of Michigan. Usually a KP Index of 6 or higher allows those northern lights to be visible as far south as Grand Rapids. 

Here is the University of Alaska Geophysical Institute’s official aurora forecast for this weekend: 

The time is given in UTC, which is four hours ahead of eastern time. The current forecast for the solar wind arrival is in the middle of the day Saturday, although experts say that time could shift. 

Scientists often use a KP index value to see how far south an aurora may be seen on earth. The higher the KP index, the further south an aurora borealis can be seen. 

Here is a look at how high the KP index needs to be in order for different latitudes to see the northern lights: 

This weekend the KP index is expected to be close to 6, which would be high enough for some West Michigan communities to theoretically see the northern lights.

The lights will be more spectacular the further north and the further away from city lights a person goes. Our local forecast does look like it will cooperate this weekend for our shot at the northern lights. Both Friday and Saturday nights should be mostly clear.