There is a bit of a grey, cloudy start for many this week before a marked change to colder conditions. 

On Tuesday the winds start to pick up in northern Scotland as a low pressure system approaches the UK from the west. This system will then bring a spell of heavy rain and strong winds for much of the country on Wednesday and into Thursday.

As the low pressure system passes to the north of Scotland it will draw down cold air and by Friday the whole of the UK is expected to be under the influence of an Arctic Maritime air mass. Daytime temperatures will vary from just above freezing to around 6 °C, and with strong winds continuing to affect much of the country, wind chill will make it feel bitterly cold.

Strong winds and coastal gales on Thursday and Friday are also expected to lead to large waves which if they coincide with high tides down the east coast, could increase the risk of coastal flooding.

Met Office Deputy Chief Forecaster Chris Bulmer said: "On Friday conditions will be cold enough for any showers that we do see to fall as snow across the country. The most frequent showers and greatest risk of snow settling, which may cause disruption, will be for areas exposed to a north to northwesterly winds. There is still some uncertainty regarding the precise wind direction later in the week and this will be key to determining where the largest snow accumulations will be.”

Despite the cold, many central and southern parts should still see a good deal of dry and sunny weather.

Blizzard conditions are likely over high ground in the north during the snow showers.

Why is it turning cold?

There are a wide number of weather events around the globe that can have an influence on our weather here in the UK. One of those is La Niña, which has been much talked about in the media, with reference to the fact that a strong La Niña was likely a major influence behind the infamous snowy winter of 2010.

La Niña is the cool counterpart to El Niño. La Niña leads to cooler-than-average temperatures in the waters of the eastern equatorial Pacific. This can have an impact on the atmosphere which, in turn can influence the weather here in the UK. Early in the winter La Niña can bring colder-than-average conditions, while later in winter it encourage warmer and wetter-than-average conditions. At the moment La Niña is in a weak phase and is likely to stay this way all winter, most likely shifting to neutral conditions in the spring or thereafter.

Although La Niña can influence the UK’s weather over winter by bringing colder-than-average conditions in the early part of the season, it is only one influence and there are many other factors, such as the jet stream, which can affect the natural variation of our weather.

There is the potential for the weak La Niña signal to affect the UK’s weather this month, but it is vying for influence of the UK winter weather with a range of other competing global climate influences which can also affect our weather.

Whatever weather we experience over the next few weeks and months you can make sure you and those around you are prepared for winter weather and can cope with its impacts.

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