Long Range Weather Forecast For Ireland (02 May 2021)


TRENDS for the week of 2 to 8 May, 2021

-- Temperatures will average 3 to 5 deg below normal values.
-- Rainfall will average 25 to 50 per cent above normal values.
-- Sunshine will average 50 to 75 per cent of normal, and winds will become much stronger than they have been in the past two weeks (very strong at times Monday into Tuesday).


TONIGHT will become windy with intervals of rain and some fog especially over higher parts of the north where it could produce very poor visibility at times. Winds will continue to increase from the southeast, veering to southwest in parts of Munster towards morning. Temperatures will be steady 4 to 7 C. Rainfalls of about 10 mm expected.

MONDAY will continue wet and windy with the winds veering gradually around to a westerly direction, becoming very strong especially from Galway Bay south to Kerry, and later along the south coast. Speeds of 70 to 110 km/hr are possible. Temperatures will peak at only around 13 C in the south, 9 or 10 C north, and will be falling slowly by late afternoon with passing squally showers with hail and thunder possible. There could be some brighter spells in the strong winds too. A further 10 or 15 mm of rain is likely.

TUESDAY the storm will be slowly moderating but the morning could remain very windy especially in coastal areas of the west, and wherever a northwest wind is channelled by the terrain (at least 60 to 90 km/hr in exposed areas). It will remain unseasonably cool with passing squally showers, and the risk of wintry showers on northern hills. Lows around 3 C and highs 7 to 12 C (coldest in Ulster).

WEDNESDAY and THURSDAY will continue unseasonably cool with passing showers, some of which could turn wintry at times in Ulster, Connacht and parts of north Leinster, as well as higher terrain further south. Winds will not be as strong, northwest to north 40 to 70 km/hr, but they will add a chill to this outbreak. Highs both days only 7 to 12 C with morning lows around -1 C possible. There is some chance of a sleety cold rain with snow on hilltops pushing into parts of the south around Wednesday night into Thursday, and this will turn winds there more to an easterly direction, but the partly cloudy, showery regime is likely to be unbroken further north.

By FRIDAY into SATURDAY, a second Atlantic storm may directly affect the weather in Ireland, although some guidance takes this low just far enough south to be more of a problem for northwest France and southern England. There's a risk of a persistent cold rain in northeast winds, again with some potential for wet snow to mix in or fall on hills. Temperatures will be very cool for this time of year, possibly only around 6 or 7 C in some places; the further north one goes, it may actually become a bit milder just because of the sun getting through the overcast more often away from this southern storm track.

By SUNDAY next weekend this particular disturbance should be moving away but leaving a cold northerly flow with showers and temperatures still quite cold (8-10 C).

The following week looks a bit warmer in stages, as the colder air mass will moderate over Ireland and Britain but there will still be passing frontal systems bringing some rain and temperatures will only come back up a few degrees into the 13-15 C range.

Peter for IWO