Long Range Weather Forecast For Ireland (20 January 2021)


TONIGHT ... Partly cloudy west, overcast east, some further outbreaks of wet snow or sleet, quite cold, with moderate northerly winds picking up slowly but surely to reach 40 to 60 km/hr northwesterly by morning. Lows around -1 C except somewhat higher near north coast and some parts of the Atlantic coast.

THURSDAY will be breezy to windy at times with bands of mixed wintry showers developing especially around Donegal Bay and west of Galway and Clare ... these will push well inland moving a little south of due east, and dropping a wide variety of sleet, hail, wet snow and cold rain, partly separated out by elevation (snow will be most likely above 200m elevation, rain most likely near sea level). Highs 2 to 5 C inland, east and south coasts, but near 7 C on the west coast. Winds west-northwest 50 to 80 km/hr. Much stronger winds and heavy high terrain snowfalls are expected from storm Cristoph over in southern and central Scotland and parts of northern England, northwest Wales. There could be as much as 30-40 cms snow in places. The Dublin and Wicklow hills could see 5-15 cm additional, mountains in Ulster and Connacht could also see significant falls. Mountains further south will be more dependent on whether or not the sea effect bands happen to hit their vicinity or not. They could also get 5-10 cm falls if so.

will be a more sunny than cloudy day, still quite cold, but not as windy. There will be a few weaker bands of sea effect mixed wintry showers, turning readily to snow inland Ulster and Connacht, but making little further progress breaking up around the midlands. West Munster could also still see a few isolated wintry showers. Morning lows near -4 C and afternoon highs 2 to 5 C.

SATURDAY will be partly cloudy and there could be an interval of light snow in some areas, with coastal sleet, but this will come and go within a few hours, and other parts of the day will be brighter. Lows near -4 C and highs 2 to 5 C.

SUNDAY will also be partly cloudy and cold with more chances for light outbreaks of snow or sleet, lows near -5 C and highs 2 to 5 C.

MONDAY will be clear in the northeast with a sharp frost then eventually overcast like all other regions starting out, and a cold sleety rain or wet snow may develop by late in the day, lows -5 to -2 C and highs 3 to 7 C.

TUESDAY a frontal system may divide the country around Mayo to Meath, with areas north of that prone to mixed wintry sleet and wet snow, areas to the south a little milder with rain, highs 2 to 4 C north, 7 to 10 C south.

By mid-week more active disturbances are likely, and there could be further battleground scenarios with fronts dividing Ireland into colder north and milder south, but the boundaries may fluctuate further south at times, bringing sleety or snowy intervals as far south as inland Munster and south Leinster. One final push north around Thursday 28th may lead to a significant storm that I feel may not be entirely "visible" to the forecast models at this range.

The outlook beyond that is for a somewhat colder interval with some influence from high pressure in Scandinavia, southeast winds and mixed bands of precip likely. A very strong arctic high has pushed west to the north of Siberia for several days now and the models say it will drop southwest towards northern Russia but most of it will return to Siberia; however, a bubble of high pressure breaks away from it and tries to work closer to Sweden and Norway. This holds the key to any possible colder spells in February, and may interact with the stronger stages of the stratospheric events that are already underway. So we can't rule out a more severe wintry interval than any of the three relatively tame ones we will have seen by then.

-- Peter O'Donnell for IWO