Winter Forecast 2015/16


18 October 2015.

This is a preliminary version of my winter outlook. I will update it some time around the middle of November. I sought some input from other members of Irish Weather Online, and I did a review of other credible forecasts that have been made available so far. This is basically my own work, however, not looking to share any blame too widely.

First of all, I expect November to be variable and average near normal for temperatures and precipitation. Expect a wide variety of weather types and one or two rather windy days but also a lot of anticylonic weather.

December and some part of January (at least the first half) will probably be mild more often than cold, but with spells of anticyclonic weather bringing quiet perhaps foggy conditions, and somewhat colder temperatures interspersed with milder southwesterly flows and possibly one or two stormy periods. If these storms develop, they would likely be followed by several days of northerly flow, local hill snow and gradually moderating temperatures. During this part of the winter, there may be considerable snowfall in higher parts of the northwest, if not in other parts of the country. There will be mild enough temperatures at times to melt lying snow so it won’t likely be prolonged.

Later in January and for some part of February, more significant blocking appears likely, and I think there may be a spell of significant and perhaps extreme cold developing over nearby western Europe and possibly Britain as well. The delivery of cold to Ireland is always an issue, but at this early stage I would expect occasional freezing temperatures and some snow for parts of the east if not more widely distributed. This colder pattern is not likely to reverse itself quickly and it may just fade out through March.

I will revisit this forecast in November and give a final version with some of the reasoning added. At this point, would just say that the El Nino will not overwhelm the closer and therefore more significant cold Atlantic signal. However, I don’t think that it will completely fail to interact with the Atlantic and European patterns, which is the main reason for thinking there could be perhaps one or even two significant windstorms as there were in Dec 1997.

Watch for an update in mid-November, at which time I will try to give more comprehensive reasoning for the final forecast selection.
Peter O’Donnell for IWO