A short period of colder Polar Maritime air will be in place throughout Friday until Saturday morning. The airmass will be relatively cold.
There are two windows for low level snow: Friday morning 7am-10am and Friday 6pm-9am Saturday. The coldest air will be around Friday evening. The gap in time is due to a warm sector coming across the island on Friday afternoon (early).
This is based on the snow-rain charts on Meteociel and the height of the wet bulb zero line amongst other factors.
Colder air flowing back in
Needs to be <500 metres for low level snow.
Warm sector: snow limited to extreme mountain tops during this part of the day.
Wet Bulb 0c Level:
Needs to be <300 metres. It is marginal during Friday daylight hours.
So, in summarising; there is a risk of low level (close to sea level) snow in any showers in the NW, N and W of the island on Friday morning and the overnight hours. The greatest likelihood is on Friday evening.
Elsewhere, inland areas of the Midlands of ROI may see some snow showers, but the S and SE will most likely be rain below 300 metres based on the charts. Areas on the far NW and W coasts may just see sleet or hailstones.