Icelandic volcano Katla has been raised to colour code Yellow by the Icelandic met office.
Katla lives beside Eyjafjallajökull, the volcano that closed much of Europe’s airspace for a week or so in 2010.
Colour code yellow means that there is increased activity, but no eruption … as of yet.
It doesn’t mean that an eruption is ‘expected’ either, but given the proximity of Katla to the site of the major eruption in 2010, there may be correlation. Icelandic scientists have also said that an eruption of Katla is overdue.
For now, keep an eye on updates at http://en.vedur.is/weather/aviation/volcanic-hazards/