The Kp-index is the global geomagnetic storm index. It ranges from 0 to 9, where a value of 0 means that there is very little geomagnetic activity and a value of 9 means extreme geomagnetic storming. Depending on your geomagnetic latitude (were you are), and on the Kp value, you will know if there is any chance for you to see an aurora.
How does the Kp-index work?
The table below shows you until which latitude you will be able to observe the Auroral Oval, depending on the Kp strength.
|Kp||Geomagnetic latitude||Auroral activity|
|Kp 0||66,5° or higher||Very low|
|Kp 5||56,3°||Minor Storm|
|Kp 6||54,2°||Moderate storm|
|Kp 7||52,2°||Strong storm|
|Kp 8||50,1°||Severe storm|
|Kp 9||48,1° or less||Extreme storm|
Example: With a Kp 0; you can observe an aurora in Tromso in Norway, with a Kp 5; you can see the aurora all the way to Edinburg in Scotland, and with a Kp9 (the maximum that is possible), you can view an aurora all the way to Marseille in France.
Prevision for the next 3 days