Long Range Weather Forecast For Ireland (20 August 2021)

TODAY there is a rather disorganized frontal system slowly moving through, with two bands of rather heavy rain likely to develop, with one peaking this afternoon over the inland southeast, and another following on that will probably have some heavy downpours near the Shannon especially the lower portions around Lough Derg. Those two areas could see 20-25 mm of rain, but other locations closer to the 5-10 mm range from less active showers. Highs will be 18 to 21 C.

TONIGHT these areas of rain will lose some of their intensity but will continue to drift east with the leading one heading towards Britain but the second one will be dragging along rather slowly into Leinster, lows falling to about 14 C.

SATURDAY will see the eastern showers lingering and possibly becoming thundery in some spots, with local 15-30 mm downpours. Most other regions will begin a slow clearing trend that may bring a few sunny intervals and highs generally 18 to 20 C.

SUNDAY will be transitional with some of the moisture left over forming rather extensive clouds with some better sunshine possibly inland west and north. Lows near 12 C and highs 18 to 20 C.

From MONDAY on, about a week of fine weather is likely with high pressure almost directly overhead. There could be some localized low cloud and marine fog or drizzle near some coasts but even there, it probably won't persist in any one location but could just show up each day in one or two locations with almost all other places nice and sunny, with daytime highs slowly rising into the mid-20s. Nights should be fairly comfortable unlike some parts of the July hot spell and overnight lows should remain in the 11 to 14 C range, possibly a few degrees lower in some inland counties.

This fine spell of weather will most likely break down towards the end of August because the high pressure involved will then be drifting further west, opening the way for cooler northerly winds to set in. Temperatures could come down rather steadily after the weekend of 28th-29th (or even during that weekend) to reach mid-day values of only 15 C or so, once the northerly sets in. But there should be almost a week of good weather to enjoy before that begins. 

Peter for IWO.