Today the weather charts and forecasts have been increasing the likelihood of seeing wintry showers, across the Midlands and Southern England. Northern England, Wales, Scotland and Northern Ireland have already seen snow falling throughout today, with more also expected tonight into tomorrow.
The question which is being asked consistently is: Will I see any snow? The answer is above 150m the risk of snowfall greatly increases, whilst sea level areas have around a 40-60% risk. The main part to watch tonight into tomorrow, is the development of the snowline on the weather radar. If you see the snow developing ahead of the forecast charts, than you’ll have a greater risk of seeing snowfall in your area, but if the snowline is lagging behind, it will more likely be a sleet or rain event.
The problem this system brings us, is the majority of the colder air is actually flowing down the west of Ireland, rather than straight down across the United Kingdom. This means that the air over the country is actually only -2 to -5°C which will bring some snowfall, but for the optimal chance we need to see the pressure system dragging in the deeper temperatures at -7 to -10°C.
The above chart shows the expected precipitation type as of the 12z run of the WRF weather chart, also known as the NMM. You can see the snowline towards the end of the chart run, near enough splitting the east from the west, and it is this, we need to watch to dictate what type of precipitation will fall.
Looking ahead on the WRF (3 hourly) chart, running until Sunday 3rd January, the outlook remains cold for all areas, with further widespread frosts expected, and further potential for wintry spells to affect all areas of the United Kingdom, mainly across the north, rather than the south. Going even further into January the GFS is still providing hope for a deeper cold air system, with it building over Scandinavia along, with Greenland and Iceland, so we will have to keep an eye on this development as we move into the New Year.