Ireland is facing extended cold winters and low temperatures lasting into the early summer according to the country’s leading weather expert.

As farmers count the cost of disastrous weather so far in 2013, the country’s leading climatologist Professor John Sweeney offered scant consolation in an interview with the Irish Independent.

The Maynooth College professor issued his warning as farmers import fodder from Britain and France to keep their cattle alive and clothes shops begin to stock their autumn and winter collections.

A member of the UN’s Intergovernmental Panel on Climate Change, he said Ireland can expect more of these extreme cold snaps in future.

He also confirmed that Ireland’s weather is being influenced by the jet stream, the meandering high-altitude river of air that typically steers milder air towards Ireland at this time of year.

The professor said: “The jet stream has shown a tendency to go very far south recently. At the moment it is locked over Morocco and the Northern Sahara.

“As a result we are getting the colder polar air streams that we wouldn’t normally expect at this time of year. That has given us the cold showery weather that is causing such problems for farmers.”

The report says that in order for grass to grow farmers need soil temperatures above 48 degrees Fahrenheit.

Temperatures for the first three months of 2013 have remained low with March the coldest month on record in many areas.

The paper says climatologists are reluctant to draw conclusions about climate change from relatively short spells of weather.

But Professor Sweeney said: “If the models for climate change are correct we can expect these kinds of aberrations to become more common.

“They will manifest themselves in cold snaps and more intense downpours of rain. That does not mean an end to global warming. It just means that we will have more extremes.”

The Maynooth College expert outlined research showing that the loss of summer ice and the warming of the Arctic is playing havoc with the jet stream, and reducing its strength.

He added: “Because the jet stream has less vigour it is wandering around like a river with less gradient, and it is getting locked in strange positions.

“We are getting air flows from unusual directions for long periods of time. This spring we have mostly had a north-westerly air flow.”

But Ireland may still enjoy a hot summer according to Professor Sweeney.

He said: “We could get an extremely warm summer later in the year if the jet stream is locked in the opposite position.”

Government weather service spokesman Gerald Fleming also spoke to the paper about Ireland’s current cold conditions.

Head of the forecast division at Met Eireann, Fleming said: “It is difficult to ascribe day-to-day weather changes to climate change.

“However, a lot of research is going on into the frequency of extreme weather events that we have seen recently. It is not definitive, but there is a suggestion that climate change plays a role in that.”