Cold spell to continue for much of week as northerly winds sweep in

WITH SUB-ZERO temperatures last night Met Éireann said the current cold snap will continue for much of the week, with heavy night frosts and some snow showers expected, especially in the northern half of the country.

The return of winter with a vengeance yesterday led to flight delays, minor difficulties for drivers and the cancellation of some ferry crossings, but the snow that fell in many parts overnight had melted before most people rose to meet the day.

Temperatures as low as minus 4 degrees were forecast overnight and a further sharp to severe frost and some fog patches are expected tonight. Temperatures have plummeted across northern Europe as polar winds stream down on the continent. In Britain, the Meteorological Office issued severe weather warnings for southern England, the north of Scotland and southwest Wales, with as much as three inches of snow expected in some areas.

Dublin airport suffered knock-on effects from the Heathrow chaos, with delays of up to four hours to flights to and from London.

Two Aer Lingus flights and one British Airways flight were cancelled.

In Britain, British Airways was forced to cancel over 100 flights through Heathrow and Gatwick at the weekend. Passengers were warned to expect delays as snowfalls added to the disruption caused by software problems with the computerised baggage system at Heathrow's new Terminal 5.

Technical failures have led to the cancellation of more than 450 flights from Heathrow since the terminal opened in late March.

Snow in April is unusual but not unprecedented, according to Aidan Nulty of Met Éireann, who put the blame firmly on northerly winds blowing down from the Arctic. "It all depends on where our winds are coming from. Last week, before the winds switched from the southwest, we had temperatures of up to 18 degrees centigrade, but people never ask 'why?' when we have mild weather." Less than an inch of snow was reported in areas hit by overnight showers.

Mr Nulty said we could expect further snow showers but because the ground is so warm, the snow will not last very long. Temperatures in the second half of this week will rise, he said, but not by much.

AA Roadwatch said overall driving conditions were good in spite of the weather, and the overnight frost and snow had cleared quickly. "There was a warning that snow would accumulate in northern parts of the country and on higher ground but the Sally Gap, Barnesmore Gap and Glenshane pass were all reported to be fully passable this morning," said Nicola Hudson of AA Roadwatch. No road closures were reported.

Age Action Ireland warned again that elderly people are particularly vulnerable to cold weather and urged relatives and neighbours to be vigilant.

The Irish Ferries Jonathan Swiftsailings on the Dublin to Holyhead route were cancelled due to bad weather. A number of flights arriving at Dublin airport from London Heathrow and London Gatwick experienced delays and there were some cancellations.

Meanwhile, the Dublin Airport Authority has warned that essential maintenance work in the main runway may result in increased aircraft noise over many parts of the city. The use of a substitute runway from today for nine weeks may result in increased noise levels in Santry, Beaumont, Artane, Clontarf and parts of north County Dublin, the DAA warns. In certain weather conditions areas in Dún Laoghaire, Rathdown and surrounding areas may also experience a slight increase in noise levels.