Then on SATURDAY, winds will turn back to the south-southwest ahead of another Atlantic low, this one of more modest intensity, but still quite strong for this time of year. Rain will spread in during the day and it will be rather cool with highs only around 13 to 15 C. Rain will be heavy at times overnight into SUNDAY morning and there could be another 10 to 20 mm of rain in places. SUNDAY will become partly cloudy to overcast with winds west-southwest at about 40-70 km/hr, passing showers or outbreaks of light rain, and highs near 13 C. MONDAY will see the dying remnants of this low drifting across Connacht and Ulster, so it will remain unsettled and mostly cloudy with temperatures still quite depressed at around 12 or 13 C.
From about TUESDAY on, there will be a welcome change in the weather, not any large-scale warmup because high pressure is going to stay a bit too far to the west, keeping a slight northeasterly flow in place. That will probably lead to lower temperatures in Leinster and east Ulster than other regions, so would expect several days with highs of about 14 C in the east, 18-20 C in the west responding to longer sunny breaks. There could also be some patchy cloud in the vicinity of the Irish Sea in this otherwise dry spell. Parts of Britain will benefit too, but they will also be somewhat closer to a source of weak low pressure areas that could form over the North Sea into Belgium and Holland, spreading cloud into the southeast and even some rain at times, but that may avoid Ireland either totally or mostly during the latter portions of the week.
Rather than any scenario of a long gradual warming trend that could happen with stalled out high pressure, it looks more like the high will depart for the central Atlantic Ocean in early June and open things back up to unsettled northwesterly flow which cannot be any warmer than average at best (and will likely be a few degrees cooler).
In the central Atlantic now, a low is forming and heading west-southwest towards Bermuda where it could briefly become the first named tropical storm of 2021. Further west, high pressure is stationary over the east coast of the U.S. so the golf event there (PGA Championship) will enjoy some fine settled weather all weekend.
Peter for IWO