Long Range Weather Forecast For Ireland (04 May 2021)

TRENDS for the week of 4 to 10 May 2021 --

-- Temperatures will average 2 to 4 deg below normal values.
-- Rainfall will average near normal, possibly a bit above in some parts of the south.
-- Sunshine will average 50 to 75 per cent of normal values. Wind speeds will return to more moderate levels soon.


will become partly cloudy with just isolated showers although some risk of wintry showers over higher parts of the north. Sharp frosts could develop in central counties. Lows -3 to +2 C.

WEDNESDAY and THURSDAY will continue partly cloudy, breezy and cold with scattered showers, one or two with hail and some risk of isolated wintry showers over higher terrain. Winds not as strong, northerly 30-50 km/hr at times. Lows both days -3 to +2 C, and highs 8 to 12 C.

FRIDAY will be cloudy with a few sunny breaks, and scattered outbreaks of light rain, more prevalent in the south. Winds will turn somewhat more easterly and could be moderate near the south coast. Lows -2 to +3 C and highs about 10 C.

SATURDAY has an uncertain outcome, some guidance brings in milder air and allows rain to spread quickly north with some clearing to follow, but other guidance gives the colder air a greater chance of holding this development back and shunting any successful warming further east into southern Britain. If that is the case, it could rain most of the day in Ireland and temperatures would only creep up to about 12 C in the south and east, staying closer to 9 or 10 C in the west and north. I think the actual result is a toss-up or "even chances" at this point.

SUNDAY ... the forecast uncertainty reaches a second phase here, if the milder air does manage to win out on Saturday, it might hang around in the south and east for much of Sunday with overcast skies and some outbreaks of rain, temperatures 11 to 14 C. If the colder and wetter solution works out on Saturday, rain will continue for a time on Sunday with temperatures steady around 10 or 11 C, then somewhat colder air would follow on moderate northerly winds.

MONDAY and TUESDAY of next week appear quite cold in any case with northerly breezes and isolated showers, frosts each morning with lows -3 to +2 C, highs only 8 to 13 C.

Around mid-week Ireland will be under a rather disorganized sprawling high pressure area that could maintain quite cold overnight temperatures at frost levels, but at the same time with light winds and some sunshine, the days might become a bit more typical of mid-May (12-15 C).

From then on, a rather chaotic pattern with a slight easterly tendency emerges, which could bring a mixed bag of nice days, overcast and wet days, and temperatures oscillating in the 13 to 19 C range, so at least quite a bit more seasonable for mid-May. 

Peter for IWO