an update finally Heavy snow. Icy Conditions UPDATE 15:00 19/12/2009 Heavy snow and icy conditions are forecast to affect Northern Ireland from Saturday Evening and continuing into Sunday and Monday. The heaviest snow is expected in Co Antrim, Co Londonderry and Co Tyrone. 10 - 15 cm is expected at low levels with local falls of up 20 cm and 15 - 25cm over high ground. Co Armagh, Co Down, and Co Fermanagh are expected to escape the worst of the snow with 5 - 10 cm at low levels with 15 cm on high ground. Disruption to travel and power networks is likely. Further updates will be issued later today Please stay tuned to weather forecasts.