by P. Homewood, March 19, in NotaLotofPeopleKnowThat
If you had not noticed (!), it has been a mild and wet start to the year here in the UK, and also across in NW Europe.
No doubt this will be linked to global warming in due course, but in fact it is simply weather, as the CET chart below proves:
Since the year started, temperatures have consistently been within the normal band. In other the sort of temperatures commonly seen at this time of year.
However, they have also been consistently in the top half of that band, rather than being spread between cold and warm, as would happen most years.
The reason for the weather we have had is, of course, the jet stream, or more precisely the North Atlantic Oscillation (NAO), which has been strongly and stubbornly positive all winter.
The Norwegian Centre for Climate Research CICERO spotted this mild weather coming back in December, and commented on 6th January:
The unusual warm temperatures this winter and forecasts indicating milder winter conditions for January, February and March in Europe are partly due to an atmospheric circulation pattern called the North Atlantic Oscillation, or NAO. This atmospheric circulation pattern explains well the weather we get in Europe, especially in winter.
Our own Met Office explains the NAO phenomenon: