A map and a bar chart describing auroral activity has been added to our space weather service. Data from the observation stations can be seen in the map in almost real time.
During September just gone, auroras were seen glowing as far as in Southern Finland on several occasions. Auroras can be expected frequently in the sky also in the coming winter, as the Sun is blowing particularly fast particle flows towards the Earth.
Auroras can never be predicted accurately. However, they are closely linked to the small disturbances in the magnetic field that the Finnish Meteorological Institute measures at its observation stations. By monitoring this geomagnetic activity, it is possible to quickly get a general idea of the areas in which auroras are likely to be occurring.
The map of Finland on the Space weather page shows the geomagnetic activity of the past ten minutes. A separate bar chart shows the observations at the different observation stations during a period of 24 hours.
Auroras are likely to occur near the observation point when the level of magnetic disturbances exceeds the station-specific threshold level. The spot indicating the location of the station turns red when the latest measurement exceeds this threshold value. The threshold value is indicated by a red horizontal line in the bar chart.
Auroras typically occur as long zones extending from east to west. It is therefore a good idea to primarily follow the observation station closest to the latitude of your own observation point. The light of the auroras forms at an altitude of about one hundred kilometres and higher, and can be seen hundreds of kilometres away, so that if measurements north of the observation point reach the red level, it might be possible to see auroras in the northern sky. You should lift your eyes to the sky immediately as the displays often last no longer than a few dozen minutes.
Check the Space weather page for the probability of seeing auroras in Finland