Ken Ring of www.predictweather.com is author of the Weather Almanacs for Ireland for 2015. The following is extracted from his 2014 and 2015 books.
November for the Cork region brings on/off again rain with stronger winds between November 12 and 17, but mild temperatures; with the last couple of days bringing the first chance of subzeros for the season. With precipitation may come snow or cold rain around November 22, but snowfalls, if any, should be light. For most, the first snow of the season may be around the last two days in November.
December is dull and wet and with possible snowfalls in the first week, and around December 17. Christmas may see the peppering of white on hills and roofs beforehand, but mostly Christmas Day may be dry but the coldest since the first week in December. Most snow in southwest counties could be in the first half of December.
January is mostly cold and unusually dry for the first half. The first twenty days may see only very light flurry days but mostly dry skies, with the coolest period being around January 8. After January 20, the daytime temperatures get milder, at times even reaching around 14C. The last week may bring some heavy rain at times.
February’s first ten days are mainly cold and dull, with about three rain days. The windiest time of the year may be in second half of February and first half March, and that will be because the highest tides of the year are in February and March.
The probability is that we are not facing a particularly harsh winter. The brunt of winter will mainly be the first half of December, and during January up until January 20. Daytime temps should get back to being regularly over 10C from mid February. Mid winter may be milder but wetter and windier in the last ten days of February, developing into more chances of wintry weather in the first week of March, although an absence of subzeros may bring hail then rather than snow.
Although the first half of March brings more precipitation, the coolest mornings may be in the third week, and only a couple of subzero minimums that would be able to produce snow. Overnight freezing is mostly gone by March 20 and over the final 10 days the region may see only light showers.
Summer-like dryness and milder day and overnight temperatures kick in and run from the second week in April to the first week in May. The best time for holidays is June 4 to 12. Put a ring around that in the calendar as the best opportunity to take your summer break.
Closeness of perigees (days of closest earth-moon distance per month) affects the strength of the Gulf Stream. In 2013, the most powerful perigee for the year, coupled with the moon at southern declination in the last week of June, caused record high sea surface temperatures early in summer and as expected brought a heat wave on 9 July.
But in 2014 the closer perigees occurred in August together with a northern declination moon, bringing warmth and rain, and in September a southern declination moon that brought sunshine and settled conditions. In 2015, the closest perigee will happen near the end of September and will accompany a full and northward trekking moon. As a result September should be windy at times, wet and mild.
Overall, 2015 may be a warmer than average year. This method of longrange forecasting looks at trends that appeared in approximately equivalent years in the past. If we average sun and moon years we arrive at 1957-9 as being the most similar year in trends to 2015 (three moon cycles ago). Other similar years have been 1988 and 1977.
Weather tends to repeat each 9-11 years and 18-20years, which are an amalgam of lunar and solar factors. But although the sun’s orbit averages 11 years, there is fluctuation between 9-14 solar years to achieve this. There is often a 36-38-year turnabout, for instance 1975 saw the hottest summer in Ulster for 150 years. Other hot summers have been 1976, 2006 and 1995, which have been multiple years of the lunar and solar model (1995+11=2006, and 1976+37=2013)
The moon provides the timing of weather events and the sun provides amounts of heat and evaporation, which determine amounts of rain that fall. Of the two, the moon is more reliable, and despite the scepticism of mainstream forecasters, our observation is that lunar factors constitute 80-85 per cent of weather.
For more detail about what is coming for each county for 2015, Ken’s almanac is available from his website www.predictweather.com or from Amazon.