A drastic alteration in the flow of the Gulf Stream in recent years, the two recent eruptions of Icelandic volcanoes and low solar activity are combining to lead to the severe weather warning.
James Madden, long range forecaster for Exacta Weather, says both Ireland and Britain should prepare for a winter similar to, or even worse than, the experience of the last two years, when temperatures reached a 40-year low.
“I expect the 2011-2012 winter to follow a similar pattern in terms of how November and December was in 2010 for the vast majority of this winter,” he said. “It will be exceptionally cold and snowy with well below average temperatures.”
The warning comes as the National Roads Authority confirmed yesterday that it has ordered an additional 70,000 tonnes of rock salt to treat the country’s national road network next winter.
An NRA spokesman Sean O’Neill said that the supplies, which are scheduled to arrive from North Africa during the coming weeks, are in addition to existing supplies of 70,000 tonnes.
Mr O’Neill said the NRA had also been asked to oversee the purchase of a further 40,000 tonnes of rock salt to be supplied to local authorities to treat regional roads.
“We used approximately 115,000 tonnes of grit to treat the national network last winter.
“In previous years we have not been required to use more than 50-60,000 tonnes of grit,” he said.
Local authorities have started preparing for a repeat of last winter’s conditions. Cork County Council has also submitted a tender for the purchase of winter maintenance salt spreaders and to carry out alterations to council trucks.
Mr Madden advised that now is the time to prepare for these harsh conditions. “It will be exceptionally cold and snowy with well below average temperatures,” he said. “I fully expect to see records broken, with the highlands of Scotland being once again particularly hard hit.”
Commenting on the solar cycle, he said: “Periods of low solar activity at present, and what we have seen in recent years, influence the Earth’s atmosphere by allowing the stratosphere to cool. This has a somewhat more profound effect over Northern Europe and the UK in terms of colder and snowier winters, due to jet stream patterns that block warm air from reaching us and create more moisture.”
The Irish Met Office is reluctant to issue definitive long-range forecasts and Britain’s Met Office withdrew its long-term forecasts last March after predicting a “barbecue summer” which turned into a washout and a “mild winter” which developed into the Big Freeze in 2009.