Long Range Weather Forecast For Ireland (31 December 2020)


TRENDS for the week of 31 Dec 2020 to 6 Jan 2021

-- Temperatures will average 3 to 5 deg below normal values.
-- Rainfall will average about 25% of normal and some of that will be mixed wintry forms.
-- Sunshine will average near normal.


TODAY will be cold and mostly cloudy with a few brighter intervals more frequent in the south and west. Snow or sleet may develop across parts of south and east Ulster, north Leinster this morning, then whatever is left of this weak disturbance may be more mixed in its production later in the day with rain showers more frequent in the mixture, snow retreating to higher elevations of Leinster. There may be some rather heavy rain showers by afternoon still with some risk of wintry mixtures developing. Winds increasing to northwest to north 50 to 70 km/hr in some exposed locations, although not that windy for most inland. Highs 3 to 6 C.

TONIGHT will see some isolated wintry showers in a partly cloudy to overcast northerly flow, lows near -3 C in some places, closer to zero C near coasts. Feeling colder in the 30-50 km/hr winds though.

NEW YEARS DAY will be partly cloudy with passing wintry showers, moderate northerly winds, highs near 5 C.

SATURDAY (2nd Jan) will be cold with some sunny intervals, isolated wintry showers, most likely in Ulster and north Leinster, and morning lows near -4 C, highs near 4 C.

SUNDAY (3rd) to about mid-week will be cold with northeast winds, some sunny breaks each day, but a fair amount of cloud generated from the cold air crossing both the North Sea and the Irish Sea on its way, which may also give rise to some local wintry showers near east coasts of both Ireland and Britain, with slight chance of some significant local accumulations, although everything remains a bit on the marginal side, which may change over any snow showers to sleet or hail and cold rain too. Many places will just stay dry anyway. Typical overnight lows will be down as low as -6 C in central and inland western counties, -3 C in the east.  Afternoon highs 2 to 5 C., with winds generally in the 30-50 km/hr range, sometimes increasing to 50-70 km/hr near coasts.

The further outlook is for this northeast wind regime to give way to more variable conditions as the Atlantic wakes up briefly and tries to mix it up with the cold air, but eventually a new surge of cold air moves in from the north and that could be a bit colder than this first round we're going to see. Not carved in stone yet, but January could shape up to be quite cold and generally dry with slight risks of locally heavy snowfalls in a few spots. No really good indication as to when this might break down to a more normal Atlantic-dominated winter weather pattern, it has to be said that several memorable cold winters started out about like this and got colder in the second half of January and much of February, so if we're on that track, it would not come as a total surprise.

-- Peter O'Donnell for IWO

Photo from Ballycastle, Antrim by Gavin McKernan