For some reason, I have not done a blog post on my moderate El Niño Winter analogue and as a result, this is what this is going to be about.
The signals for El Niño are still there for Winter 2018-19 from the models but the teleconnections don't really support the models in this case. There is nearly zero chance of this coming out as a strong or very strong El Niño event so there lies only two possibilities of El Niño strength; weak and moderate. We're going to be looking at weak El Niño Winters in another blog post and this one is going to be about the moderate events.
The 500mb height anomaly reanalysis overall for these Winters shows a blocking area of high pressure to the southwest of Greenland backing into Canada and to the north of Scandinavia. There is a deep area of below average heights over us the main centre is just to the south of England. This reanalysis indicates a mixed Winter pattern giving off month to month variation, let's have a look at each month below.
The Decembers look wet but maybe close to average temperatures as it looks like a very northwesterly month. There is a large block of high pressure up to Scandinavia and over North America indicating that there would be opportunities for decent snow and cold at times during the month but overall, an unsettled month.
The Januaries look extremely cold and snowy. This is probably the best chart you can get for cold and snow. December 2010 had an identical chart to this one for January. Huge northern blocking over Greenland with below average heights over Europe and just to the south of the UK. The mean wind direction is a northeasterly.
The Februaries look like a knife edge between mild, wet and windy or cold and snowy.
Moderate El Niño Winters overall seem mixed with an unsettled December, a very cold and snowy January whilst February is either mild and wet or cold and snowy.