GFS weather model maps show snow falling in Northern Ireland from around 3am on March 21. Belfast and areas in the west and north face initial flurries.

Snow begins in western and northern parts before spreading. The system continues for several hours into March 21.

By 6am on March 22, settled snow covers areas across Northern Ireland. Purple shading on maps indicates snow at that time.

Met Office forecast for March 13 to 22 expects changeable conditions. Atlantic frontal systems bring rain or showers, most frequent in the west and northwest. Strong winds may accompany them.

Drier periods occur under high pressure ridges, more likely in the south and east. Temperatures remain near average, with shorter colder spells possible. Frost and hill snow feature in those periods.

BBC Weather outlook for March 16 to 22 predicts cooler temperatures. Atlantic systems deliver showery weather. Wintry showers possible over higher ground in northern UK.