The ECMWF are going for a white Christmas this year. That’s according to their latest extended range forecast temperature anomaly chart for the 21st to the 28th of December. Of course the white or blank areas of the chart don’t signify snow only where anomalies will be close to the LTA for late December so please don’t get too excited. Near average temperatures might the best we can expect this Christmas if you take a look back at the top twenty mildest and coldest winters across the UK. Only one winter in the top twenty twenty occured this century whilst ten of the mildest winters did. That must make the odds of another entry in the top ten mildest about even’s for this coming winter and 20 to 1 for a colder than average one.
Global and regional maps of weekly mean anomalies. The anomalies have been calculated relative to a 20-year model climatology. The areas where the ensemble forecast is not significantly different from the climatology, according to a WMW-test, are blanked.ECMWF