Try again. My mistake. I was looking at the G4 rating instead. The Kp index is on the left of the chart. kp4 doesn’t mean much.
On the Space Weather Now page, almost everything is a clickable link.
Under the top image of the sun in green is a label of Alerts/Bulletins. Click on the word Alerts and it will take you to a page with more links labeled Space Weather alerts, which is here....
http://www.swpc.noaa.gov/alerts/index.html
Part way down is a category labeled K-indices chart. Click on that an it takes you to this page......
http://www.swpc.noaa.gov/alerts/k-index.html
Also the top box of NOAA Scales Activity has a link to Geomagnetic Storms. Click on that and it will give you more information, the scale and grading of it. K4 is a doozy. Here’s a link to that page as well.
http://www.swpc.noaa.gov/NOAAscales/index.html#GeomagneticStorms
The Boulder K-index is the real-time proxy for the Planetary K (Kp) values that define the Geomagnetic Storm (G-scale) on the NOAA Space Weather Scales.
Category G 1 = Descriptor Minor = (Kp = 5)
Am I reading the wrong value? Looks like K4 is below the scale of notice.