From NOAA SWPC. A major radio blackout is underway, especially over the Polar regions from a coronal mass ejection that hit Earth Monday afternoon.

Update 7:25 PM US EDT: Scott Kelly on the ISS is seeing what he calls the best display he has ever seen from orbit of the aurora:

The Kp index is currently at 8 and if that holds, we could see the Northern Lights over the northern half of the U.S. tonight. Europe should be seeing them now, but because we are at the solstice the light lingers at high latitudes until nearly midnight. This is a severe geomagnetic storm, and besides severe HF radio blackouts, it will likely lead to the cancellation of “over the pole” flights due to increased radiation at flight level in these areas.

Another storm may be coming, and NOAA’s Space Weather Prediction Center has more on that here.