Warmer weather is on the way back to Ireland over the coming week, and while it may fall short of a heatwave, it is unlikely to be the last rise in temperatures this summer, according to the United Nations’ climate body.
The World Meteorological Organisation (WMO) has warned El Niño conditions are “developing rapidly” and there is an increased likelihood of “heatwaves, drought, heavy rainfall and other extreme weather events in many parts of the world”.
This El Niño, a periodic surge in warming due to an overspill of heat built up in the tropical Pacific, is characterised as “strong”, which is the third most severe of the four strength levels.
It is expected to continue strengthening from June to September and the WMO said there was “an overwhelming likelihood of above average temperatures” everywhere.
RM Block
While cautioning there is uncertainty with regional forecasting, the WMO said there was a likelihood of more rain than usual in southern European countries and drier conditions than usual in northern countries.
That includes Ireland, where any lack of rain in summer tends to lead to strains on water supplies, difficulties for farming and an increase in countryside fires.
Meanwhile, Met Éireann is forecasting a rise in temperatures to the low to mid-20s from Saturday and through next week.
The warmth will not be evenly distributed, with southern and eastern counties getting the best of it, while cloud and rain will keep northern and northwestern areas cooler.
“Donegal is going to be a lot different from Wexford,” said meteorologist Michelle Dillon.
The warm spell is expected due to the return of an area of high pressure south of Ireland.
High pressure is associated with calm, clear conditions, and this patch has gathered warm air from the Azores and west Africa, so it also brings higher temperatures.
It looks like it will linger off the south and southwest, rather than move directly over Ireland, although indications are that it will stretch into southern counties on Saturday and Sunday, and spread to western counties on Tuesday.
“The high pressure should be more dominant by midweek, giving more in the way of sunshine and, as a result, higher temperatures,” said Dillon.
“Even in the north, we should see temperatures over 20 degrees – although they may stay at 19-20 degrees in coastal areas of the north and northwest – and between the low to mid-20s across the rest of the country.”
A repeat of last month’s heatwave is uncertain. Dillon said a period of “decent” rather than remarkable weather was more likely.
