The Met Office has issued an amber weather warning for up to six inches of snow on Sunday.
The warning runs from 11pm tonight until 3am on Monday with significant amounts falling on ground over 500 feet throughout much of tomorrow, with a risk of up to 12 inches falling above 800 feet.
Strong winds may also produce snowdrifts and there's also a risk of overhead power lines icing up.
In lower areas, there's more likely to be rain and sleet, with sleet or snow in the west.
The Met Office says it will issue updates if the forecast changes.
Weather warning for storm Dave this weekend
Roads to close for music festival this weekend
How long do mental health patients stay in Manannan Court?
Could you take over this former restaurant?
Framework of new Sea Services Agreement ready, says minister
Attorney General says he's stepping down
Road closures in two towns for running event this week
Six weekend ferry crossings could face disruption