Climate change the chief culprit for stormy winter weather

Research suggests pressing need for sharper insight into changing wind and rain patterns

Storm Henry brings strong wins and high waves to Dingle, Co. Kerry and Glencolmcille and Inishowen, Co. Donegal. Video: Gerald Horgan/Enda McGurk/Redcastle Hotel

If the weather this winter seems stormier than usual, that is because it is.

It is every bit as bad as the storm-ridden winter of 2013-14, according to climate data from Met Éireann.

And climate change can now be blamed for the stormy conditions we have had to endure, at least during 2013-14. New research out of Oxford shows the extreme rainfalls that flooded the UK during that winter were associated with global warming.

Storm Henry, which cleared our shores this morning, counts as the eighth large-scale cyclonic windstorm to have lashed the country so far this winter.

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Major storms are plentiful this winter – and winter two years ago – said Aidan Murphy who handles climate inquires at Met Éireann.

“Prior to this there was a prolonged period, from approximately 2000 to 2013, with relatively few winter storms. However, winter storms across Ireland were prominent in the 1990s,” he said.

Climate change was behind the extreme rainfall and floods in Britain during 2013-14, causing more than €600 million in insured losses, according to researchers in Oxford writing in the journal Nature Communications.

They found that the changes in precipitation and in atmospheric circulation brought on by climate change increased the risk of a major rainfall event by 43 per cent in 2014.

Rain-laden air

They pointed to two factors associated with global warming – warmer air holds more water as rain and the increased number of January days with a westerly air flow that steered more of this rain-laden air across to Britain.

“This study highlights the fact that we need a better understanding of not just how and where climate change is warming the atmosphere, but also how it is changing patterns of wind and rain in order to best prepare for extreme rainfall and floods,” said Prof Ted Shepherd at the University of Reading when responding to the research findings.

If the current weather pattern continues we won’t have to wait long before Imogen is on the way.

That is the name chosen by Met Éireann and the UK Met Office after they launched an initiative to raise greater public awareness of impending medium to high impact windstorms.

Greater public safety is behind it all, Mr Murphy said. If a major storm with the potential to cause significant damage is on the way then it gives people a chance to prepare.

Adding a name to the storms as they rattle through does make it seem they are coming more frequently, but it also makes it easier for people to separate one storm from another. It also allows the meteorological services to keep tabs on a given storm so there can be no confusion when categorising weather events that traverse both jurisdictions.

Certainly the new approach has made people more aware of the status Orange or status Red weather warnings that Met Éireann issues for the big ones. Only these substantial storms will be given a name.

The list of storm names were selected from among those submitted by the public, Mr Murphy said. After Imogen we will have storm Jake, storm Katie, storm Lawrence and storm Mary.

It is almost alphabetical, but names starting with U, Q and XYZ are all left off the list.

Sorry Yolanda and Zach.

Dick Ahlstrom

Dick Ahlstrom

Dick Ahlstrom, a contributor to The Irish Times, is the newspaper's former Science Editor.