It is a Siberian blast that will leave residents across Hampshire facing bone-chilling temperatures.

The county has been put on severe weather alert after forecasters warned of a bitterly cold snap moving in from Russia this weekend.

Met office experts say the bitter conditions could last as long as three weeks, with overnight temperatures set to dip to around -5C in Hampshire although in other parts of the south it could fall to as low as -14C.

Freezing fog, ice and a blanketing of snow are also forecast for Hampshire during the next 48 hours.

The predictions are a stark contrast to mild weather across the county during the festive period, when we basked in temperatures as high as 12C - and campaigners are urging householders and motorists not to get caught out by the sudden change in conditions.

And today, the Daily Echo is launching a campaign to keep some of our most vulnerable people safe and warm this winter.

The Stay Warm campaign is urging people across Hampshire to come together to look out for our elderly friends, family and neighbours during the big freeze.

Whether it is helping to clear their pathways of snow and ice, offering to pick up their weekly shop, lending them warm clothing and hot water bottles, or simply popping in to check they are okay, now is the time to rally round and help keep our pensioners warm.

Shocking statistics reveal that there were an average of 99 preventable deaths every year in Southampton between 2007 and 2010, due to the effects of cold weather.

And charities that support pensioners across the UK fear that as many as 25,000 people over the age of 65 could die needlessly this winter because of the bitter chill.

In a recent poll by EDF Energy, a fifth of adults across the country admitted visiting elderly relatives less than they did five years ago.

And only four per cent of people quizzed said they spoke to them between seven and 10 times a week.

Anne Carty, chief officer at Age Concern Southampton, said: “Obviously we are supporting the campaign 100 per cent. This is something we are mindful of every winter and it's usually after Christmas during the cold snap when elderly people are at their most vulnerable.

“It's shocking how many people are left on their own almost freezing to death. The statistics speak for themselves.

“It's a situation we might find ourselves in one day, but a lot of elderly people are overlooked these days. It's important that we just give a thought to somebody who is alone and isolated and may not have the support of family of neighbours this winter.

“If we can all work together on this it will make a huge difference to someone's life and could be the difference between life and death for some people.”

The AA has warned that the sudden change in conditions could also cause havoc for Hampshire motorists.

A spokesman said: “Hopefully Hampshire will escape the very worst of it, but ice and snow will certainly cause problems for drivers.

“The main advice is just to keep an eye on the weather forecasts. At the moment we aren't sure exactly how bad the conditions will be, so if you are out and about over the weekend and into next week, plan your journeys appropriately.

“It's always a good idea to keep a few extra layers of clothing in the car, as well some food and a flask of hot drink if you plan on going further afield.”