The Roads Service said drivers can expect icy conditions and possible travel disruption as they set out on Friday morning.A statement said: "Temperatures are reported to be falling sooner than previously forecast, resulting in the possibility of icy conditions. Roads have been, and will be salted overnight and into tomorrow morning."Drivers should be aware of the risk of icy conditions and exercise caution."A yellow-level weather alert for snow will come into effect from 12pm on Friday and is expected to last until almost midnight.The Met Office said: "The public should be aware of the potential for very poor conditions and disruption to travel due to snow as well as temporary blizzard conditions over the higher routes, due to strong winds accompanying the system."And in addition to that, there is a concurrent yellow alert for rain with 10-20mm of water expected to accumulate widely across Northern Ireland, and a risk of flooding.The Met Office added: "While some of this may fall as snow in the north, this will soon melt and with saturated ground conditions the added water on the ground may lead to localised flooding issues. The public should be aware of the potential for localised flooding on Friday afternoon and evening due to the wet conditions."It comes after parts of NI experienced bouts of snowfall earlier in the week, particularly in towns and cities along the North Coast and parts of counties Tyrone and Fermanagh.Heavy rain and winds of up to 80mph then battered the region on Wednesday, felling trees and causing disruption to travel and transport.An ambulance carrying a patient was trapped for a time and after trees fell down in front of it and behind it along the Killyleagh Road in Co Down.It later completed its journey from the Downe to the Ulster Hospital.There was an overnight ice alert in place from Wednesday evening into Thursday and heavy snow is reportedly still lying in parts of the region.Translink said Ulsterbus's Augher & Clogher services to/from Omagh, Co Tyrone were unable to operate due to adverse weather conditions.Also in Co Down, the A2 Rostrevor to Warrenpoint Road remains closed at the Drumsesk Road junction. A section of the road collapsed due to the weather on Wednesday.Diversions are in place via Rostrevor, Hilltown, Rathfriland, Mayobridge and onto Warrenpoint.