You might have thought it was cold enough this morning but this week is going to get much colder as Arctic air heads our way from mid-week onwards. Highland Scotland was sub zero on Monday morning and the dampness is making it feel colder. By Friday, much of the UK will start the day with a widespread air frost and temperatures of -10C appearing even in the south. There will be frost and expect widespread ice with further snow warnings in the far north.
This first true cold spell for the UK will be quite a shock to the system. It follows the third warmest UK Autumn (September, October, November) on record according to provisional figures from the Met Office. For those who are working from home, or indoors for all of the day, keeping warm is tricky, especially if you are not moving about much.
Change of air mass to Arctic Maritime. These thickness charts show 'height' of a layer of air between two pressures. The colder the air, the thinner the layer as the air is more dense. The 528 line is often seen as a change to wintry precipitation in the UK, a rule of thumb. This air well beyond that.
Some workers may be choosing to travel into the office as the temperatures plummet just to be in a warmer building. Ice on the roads and pavements might put some elderly people off popping to the shops or visiting their regular activities due to fears of falling. The Met Office has a health/weather system service for England which highlights extreme heat in summer and severe cold in winter. it looks at how they will impact health services. On Monday 5th they issued a Level 3 Cold Weather Action which relates to thresholds of:
Mean temperatures below 2 degrees Celsius for 48 hours or longer AND/OR Heavy snow and/or widespread ice. It is shown in orange (amber) but this is not the same as the UK weather warnings. There is also a red level (National Emergency).
One example area, is Northeast England “Cold with overnight, potentially severe, frosts and temperatures persisting near freezing by day. Wintry showers possible, especially along coasts, bringing a risk of icy patches.”
For most of the UK, it will be dry and much colder gradually through Wednesday and then for the rest of the week. The air from the Arctic will reach down through the Norwegian Sea and result in widespread frosts and severe frosts in places. By day, temperatures will stay around or just above freezing.
It has been very wet over recent weeks, so there is still plenty of moisture and even standing water around. All of that brings the risk of ice. Remember to check outdoor water bowls, and maybe empty the garden hose. How is your screen wash? Is it still on autumn dilution or pure 100% screen wash which says down to -18C or -22C, most say -3C. Prestone is a good one. Also de-icing the car properly takes time. So, the highly honed timings for the school run, or getting to the park & ride will need adjusting. Road Policing are out and about checking that you aren’t driving along with a letterbox gap cleared on a fully iced-up windscreen.
At home, the current advice for energy saving is to heat the person, not the room. So, layering clothes, thermals, good socks with slippers and a snood or scarf around your neck makes a difference.
There are all sorts of heated pads available, like min electric blankets. For your lap, back or underfoot. The Cold Weather alert states
“Look out for friends and family who may be vulnerable to the cold, and ensure they have access to warm food and drinks and are managing to heat their homes adequately. Try to maintain indoor temperatures to at least 18°C, particularly if you are not mobile, have a long-term illness or are 65 or over. Avoid exposing yourself to cold or icy outdoor conditions if you are at a higher risk of cold-related illness or falls.”
The advice, for a fairly well-insulated house, is to keep the thermostat at 17C if you do want your heating on. That steady heating by day could keep the worst of the cold and damp at bay. A cold, damp house with little ventilation is more likely to see mould problems. The condensation needs clearing from window panes. In bathrooms, use a modern extractor fan with the doors and windows shut. Opening a window in cold air does not help unless it is very windy outside.
Open the curtains especially if they are on the sunny side of a home. It will add some warmth to the building, even with the short time of daylight in December. A quick, brisk walk at lunchtime might also help. Just to get your own circulation going a bit.
There will be good weather over much of the UK for getting out. Fine sunshine and light winds for most. It will just be very cold. Any snow showers will be driven by the wind, so areas affected will be the Northern Isles, mainland northern Scotland and then any showers that manage to clip hills along the coasts. The North York Moors look prone, the north coast of Northern Ireland could also see sleet and snow showers. West coast of Scotland islands and perhaps by Saturday clipping the far west of Wales into north Devon. Wednesday and Thursday look to have large areas of sunshine inland but more cloud around by Friday in the north and east.
There might be small features caught in the flow that bring snow further south during the nights. We’ll have to wait a bit for that kind of detail, for now just prepare for some winter cold. Will it snow?