Solar flares disrupts Swedish air traffic!
 

According to Luftfartsverket, solar flares disturbed the radar antennas which led to the cancellation of flights as the planes could not be seen on radar screens.

Solstorm stoppade flygtrafiken ? radarbevakningen kollapsade - DN.SE

Scientists are mildly sceptical since the flares didn't even qualify for a Class 1 on the 5-grade scale.

Forskare: solstorm dålig förklaring till radarstopp - DN.SE

Only southern Sweden was affected, including Arlanda and Landvetter.

See my post http://www.pprune.org/atc-issues/570...ml#post9344095 about the recent official "report" on the matter.