Potential for Major Aurora Tonight!

You might go outside after dark tonight and look north--a significant aurora may be visible over Washington.

A severe geomagnetic storm is occurring following a major coronal mass ejection (CME).

The GOES weather satellite orbiting Earth noted a powerful proton flux produced by the solar storm two days ago...so we knew it was coming.

An important measure of the potential for an aurora is the Planetary K index (Kp).  My own experience is that we don't see much auroral activity around here until the index gets to 7.  At 8, the changes are good.  9 it is certain.

As shown below, we are now at 8.5 (see below)

And the NOAA predictions suggest relatively high values this evening (see below).

The NOAA Space Prediction Center predict a decent aurora over us:

The big issue is clouds.  Right now, the skies are fairly clear above us (4 PM)--see below.  There is some high cirrus to the south and west--which may be an issue.

The high clouds to the southwest are clearly shown on the latest infrared satellite image (see below).

Because of the clouds, there are no guarantees....but I suspect there is a real chance tonight. 

 So once it is decently dark (after 9 PM), go to a dark place with a view to the north.  In Seattle, I recommend the kite hill at Magnuson Park.....that is where I will be.   

Seattle of Seattle Parks Department, please don't close the gate!