Long Range Weather Forecast For Ireland (24 December 2020)

TRENDS continue about the same, average temperatures will be 2-4 deg below normal values, rainfall will be about half of normal and some of the precipitation will take wintry forms, sunshine a little above normal with the colder weather.


TODAY will be bright and cold, with a moderate northerly wind of 40 to 60 km/hr. Some bands of sea-effect showers will form, moving in from the North Atlantic into Connacht and the midlands. As they get further inland and encounter higher terrain, some will begin to drop local sleet or snow, but amounts will be small. Shower activity over the Irish Sea may remain largely offshore but occasionally may move into coastal Wicklow and Wexford. Any that can climb up the east slopes of the Wicklow hills would likely turn to snow, if they can get that far west. Highs today will be in the range of 4 to 7 C, colder values inland north.

TONIGHT will see a widespread frost although it may not last until Christmas morning in parts of the west as cloud increases there, but otherwise lows could fall to the range of -5 to -2 C.

CHRISTMAS DAY will begin rather calm and frosty in the east and some parts of the midlands, inland south. It will likely warm up a bit faster in the west and north, eventually reaching 8-9 C there while further east highs of 4-6 C are more likely, but temperatures will be slowly rising by the evening hours in all areas, as a band of light rain moves down from the northwest.

SATURDAY 26th (St Stephen's Day) will be a windy and briefly milder day with the highest temperatures of 9 to 11 degrees occurring either in the late overnight or morning hours, with a gradual drop back to colder values (5 to 8 C) by afternoon and evening. Some outbreaks of rain are likely (5-15 mm) with winds westerly 60 to 100 km/hr.

SUNDAY 27th will turn considerably colder with mostly cloudy skies, a few breaks in the overcast here and there, and scattered wintry showers that may begin to drop small accumulations of snow mostly on hills at first, as temperatures will be steady in the 1 to 4 C range most of the day. Quite windy, northwest to north 50 to 80 km/hr, adding a chill factor that will make those readings feel closer to about -4 C.

MONDAY 28th will bring the risk of sleet or wet snow especially over eastern counties. The strong winds will abate for a while, except near the western coasts which will remain in northerly winds of 40 to 70 km/hr most of the day, with passing wintry showers. Lows near -2 C and highs 2 to 5 C for most areas.

TUESDAY 29th and WEDNESDAY 30th will remain in a rather cold northerly flow turning somewhat more westerly later, temperatures generally near 4 C in the daytime hours and dropping to -2 C or so at night, and occasional outbreaks of wintry showers likely, with partly cloudy to overcast skies and moderate wind speeds.

NEW YEARS EVE (31st) may see more organized wintry outbreaks of sleet or snow as low pressure from the north drifts down across the country, and temperatures may fall a few degrees further to near 1 or 2 C daytime, which could mean small accumulations of snow in at least those areas inland and a bit higher than sea level. This situation is of course a week away and the guidance could change in either direction, at the moment I would say it's a rather marginal but potentially significant snow scenario.

The OUTLOOK beyond that into the first part of January 2021 sees very little change in the pattern, rather cold with ongoing risks of wintry mixtures including some accumulating snowfalls, and temperatures generally rather low although not into the "frigid" category.

Peter O'Donnell for IWO