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WINTER IN IRELAND AND HOW LIKELY WE ARE TO SEE SNOWFALL


In Ireland the meteorological winter begins on the 1st of December and ends on the 28th of February.

The coldest months in Ireland generally January and February in Ireland and is when Ireland is most at risk of snowfall.

Snowfall in Ireland is not a rare thing and is common between the months of November to April. There has been falls of snow in the months of September, October and May in Ireland but this mostly at high ground with snowfall at lower levels a very rare thing more so over the months of September and May.

Areas that sees the most number of days with snow on the ground every year is the northern half of Ireland and north Midlands. Snowfall is more common over inland areas during winter as its colder with some coastal areas at a less of a risk due to temperature been slightly higher due to a sea breeze. Some times temperatures along coastal areas during winter can be 5C to 7C warmer than inland areas.

Forecasting snow in Ireland Often snow that falls from a cloud melts as it descends and reaches the ground as rain. However the melting process extracts latent heat from the surrounding air, causing the air temperature to cool and making it increasingly likely that the subsequent snow will reach the ground. The ideal conditions for snow are temperatures close to and just below zero, rather than colder temperatures. This is because the warmer the snow, the more moisture it contains and hence the bigger the flakes will be. A temperature close to zero facilitates the melting of snow, refreezing and the combination into larger flakes. Consequently very slight changes in temperature can mean the difference between rain and snow. This makes accurate forecasting of snow particularly difficult in Ireland and is why you may see no snow while a few miles down the road could have a covering.

Snow can settle on the ground in different forms, depending on wind, temperature and humidity. Air temperatures well below freezing produce small powdery flakes. Snowflakes that form closer to 0°C are larger and wetter and tend to stick to surfaces. In winter, snow often occurs when two different air masses collide, the cold continental air from the north or east meets the relatively mild moist maritime air from the south or west. Different parts of Ireland are more affected with snow falls that are associated with particular air masses. Snowfalls in the Northwest and West are most commonly associated with Polar Maritime and Arctic air masses .

Continues below

WHITE CHRISTMAS

In Ireland snow occurs most frequently in the months from December to March. Countrywide snow fell on 17 Christmas Days, at a least one of the Met Eireann Synoptic stations, since 1961 (1961, 1962, 1964, 1966, 1970, 1980, 1984, 1990, 1993, 1995, 1998, 1999, 2000, 2001, 2004, 2009 and 2010). There were nine Christmas Days (1964, 1970, 1980, 1993, 1995, 1999, 2004, 2009 and 2010) with snow lying on the ground at 09 am in the morning, during this period. The maximum depth of snow ever recorded on Christmas Day was 27cm at Casement Aerodrome in 2010.

SNOWFALL RECORDED BY MET EIREANN OVER THE YEARS

1951 Considerable snow fell on the 8th March in midland and eastern areas and was succeeded by a spell of cold easterly winds. Mullingar recorded a depth of snow of 15cm.

1955 A very cold northerly or easterly airstream dominated the country from the 10th to 25th February giving wintry showers and outbreaks of snow with prolonged periods of icy roads. There were 10 consecutive days with snow lying at Dublin Airport from 18th to 27th February where a depth of 13cm was recorded on the 22nd and 25th February.

1958 A cold north-westerly airflow set in on the 19th January, giving wintry showers, especially in the Northwest and west Munster. Malin Head recorded a depth of snow of 20cm on the 21st February. A depth of 17cm was recorded at Belmullet on the 24th, the greatest depth of snow recorded at this station.

1960 Snow fell countrywide on a large number of occasions in February. Dublin Airport had 9 days with snow lying from the 11th to 19th February where a depth of 11cm was recorded on the 13th February.

1962/63 This winter was one of the most severe in recent times. The winter of 1963 was the coldest of the twentieth century. The second coldest was 1947, when more snow fell, but average temperatures were not as low. Bitterly cold weather set in around the Christmas period and persisted with only brief milder periods until early March. During this period easterly winds were directed over Ireland by a large Scandinavian anticyclone, with occasional depressions bringing falls of snow, some of which were heavy. On the morning of the 31st December 1962, a depth of 45cm of snow was recorded at Casement Aerodrome in an area where there was no significant drifting.

1973 Widespread snow fell during the period 14th to 17th of February, heaviest in the Midlands. A snow depth of 25cm was recorded at Clones, Co Monaghan.

1977/78 This winter had some notable snowfalls. Snow fell in most places in the period 8th–20th February. The south and southeast were most affected, particularly on the 18th and 19th February when heavy falls of snow accompanied by strong winds contributed to the formation of large drifts. A depth of 26 cm was recorded at Cork Airport, the greatest depth recorded at this station.

1978/79 Appreciable falls of snow between 28th and 31st December 1978 were followed by frosts of unusual severity. This cold spell ended on January 6th but there were further snowfalls later in the month. The highest depths of snow recorded during this spell were Casement Aerodrome 26cm, Claremorris 16cm and Cork Airport 15cm.

1982 On 8th January there was widespread snow, heaviest in the East, where there was considerable drifting due to strong easterly winds. A severe cold spell followed and snow remained on the ground until 15th January. Dublin was badly affected. Snow was reported at most synoptic stations with the greatest depths as follows: Dublin Airport 25cm, Casement Aerodrome 16cm and Kilkenny 16cm.

1987 This spell started on the 11th January. By the 14th, appreciable depths of snow were reported particularly in the East and Midlands. Moderated north- easterly winds caused drifting. Temperatures rose a little above zero on the 15thand a slow thaw set in. Highest snowfalls recorded were as follows: Dublin Airport 19cm; Casement Aerodrome 12cm; Birr 12cm; Mullingar 12cm. Roches Point recorded its highest ever depth of snow at 12cm and a minimum temperature of -7.2 degree Celsius, the lowest there since records began in 1867.

SNOWFALL IN THE 2000 PERIOD AND OVER THE LAST 18 YEARS

2000 On the 27th December a shallow polar depression crossed the north of the country, bringing outbreaks of snow, heavy in parts of the west and north. Snow showers were widespread in all but the southeast on the 28th, giving significant accumulation of snow in many places. A depth of 19 cm was recorded at Knock Airport.

2001 Bitterly cold northerly winds brought falls of snow on the 26th–28th February, heaviest in the north and east. Snow depths up to 10cm were recorded in the east and northwest, 75cm of snow was measured in the Mourne Mountains on the 27th February.

2009/10 This was the coldest winter since 1962/3, temperatures were around two degrees below average. There were between 20 and 30 days with snow in many places, mainly in the form of showers, but snowfall accumulations were generally slight except on high ground.

2010/11 Following the middle of November 2010, the weather turned progressively colder. By the end of the month, there were accumulations of snow over most of the country, accompanied by extremely low temperatures. Both Dublin Airport (-8.4°C) and Casement Aerodrome (- 9.1°C) had their lowest November temperatures on record on the 28th. The very cold weather continued into early December with further sleet and snow, accompanied by daytime temperatures close to freezing and night-time values dropping below -10°C (-16°C at Mount Juliet on 3rd).

After an improvement in temperatures for 5 or 6 days, although still cold, it became extremely cold again from 16th with snow at times leading to significant accumulations and record low December temperatures. Snow depths of between 10 and 25cm were recorded at many locations. Casement Aerodrome recorded a depth of 27cm.

2018 Towards the end of the third week and for all of the final week OF February the jet stream pushed southwards which caused a ridge of high pressure to extend into Ireland. This resulted in easterly winds which pushed continental polar air across Ireland. country on the 27th and led to significant accumulations in eastern and southern counties on the last day of the month.Widespread snow occurred on 28th.

Lowest air temperature: -5.7°C at Gurteen, Co Tipperary on 28th Lowest grass minimum: -11.5°C at Markree, Co Sligo on 27th .

On March an exceptionally cold Polar Continental easterly airstream covered Ireland from the beginning of the month. A named depression ‘Emma’ further developed over Biscay and tracked northwards towards the country with its associated frontal systems during the first week. It yielded widespread snow, ice and low temperatures. The depression filled, but low pressure prevailed into much of the second week. Then a transient weak ridge declined allowing a milder mainly southwest airflow to dominate through the second week bringing a succession of Atlantic frontal systems. The mid-month period was subsequently very unsettled. It became more settled as anticyclonic conditions became established during the third week. However it was very cold with widespread air and ground frosts. The end of the month was unsettled as the Atlantic influence returned. There were some fine, dry and mild days too.

Widespread heavy falls of drifting snow occurred on 1st, 2nd and 3rd, heaviest in the East and Southeast, with accumulations of up to 69 cm in the Wicklow mountains. Fairly widespread snow also occurred on 18th. The month's lowest air minimum was recorded on 1st at Cork Airport with -7.0°C (its lowest min for March since 1962) while the lowest grass minimum was -13.2°C, reported at Markree, Co Sligo on the 20th (its lowest grass min for March since 2013). All stations reported air and ground frost during the month. The number of days with ground frost ranged from 10 days at Malin Head, Co Donegal to 26 days at Oak Park, Co Carlow. The number of days with air frost ranged from 3 days at Malin Head, Co Donegal to 18 days at Moore Park, Co Cork.

Kenneth from the Donegal Weather Channel


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