A big freeze is gripping parts of Europe at the start of 2017. A severe cold warning has been issued in Finland where temperatures on Friday could plunge to -40C in the far north. Travel has been affected by the bitter cold with railway tracks hit by frost damage. Bitter cold snarls #masstransit in #Finlandhttps://t.co/z89VtlFG2g pic.twitter.com/jfwc3WD6Lc—…