Good morning folks. There’s an increased chance of cold & wintry conditions into December this year. Many computer models, including the GFS, ECM, GEM and ICON models are indicating this risk. Initially temperatures will be on a steady decline during the week ahead. Surface conditions will remain relatively nondescript with a risk of frost at night, and also the risk of some fog patches. By the end of the week, daytime highs will likely be no more than 4 or 5C. By Monday, some relatively cold air will begin to infiltrate into the UK and with it the risk of some wintry conditions.
The following chart from the ECMWF weather model nicely shows the cold air beginning to effect eastern areas of the UK by this period. This shows the temperature at roughly 1500 metres above sea level. Temperatures here of -7 or -8C indicated equate to surface temperatures of around 3 or 4C.
This may be cold enough for the first flakes of snow in places. However, these are likely to be refined to higher ground during this stage. This is because the air in place is unlikely to be cold enough to allow snow to reach lower levels. Areas above 400 metres above sea level run the risk of some scattered accumulations of snow into the first part of next week. Overnight frosts are likely, especially in the west, where there will also be some decent winter sunshine on offer. Further east, conditions are likely to be somewhat more disturbed, gloomy, breezy, with the risk of some wintry showers. Again, any snow accumulations are likely to be restricted to ground above 400 metres of elevation for the most part.
The more interesting developments are likely to take place from around the 6th of December onwards. Most weather models are beginning to indicate the risk that high pressure will move towards Greenland, allowing cold air to begin to infiltrate out of the north pole and towards central Europe. If this occurs, it has the potential to plunge most of central Europe into a spell of dramatic winter weather, with the risk of significantly colder than average temperatures and snowfall. This is an outcome that is being monitored very closely. The following chart from the ECM nicely shows the high pressure over Greenland on the 9th of December, with the subsequent Arctic flow pushing into the UK.
This is currently the most favored outcome. So to summarize, the possibility of winter proper in the UK has just increased! Stay tuned to our blog for further updates. And as always, use our live snow map and snow forecast system for high quality data when the wintry weather does arrive.