A Beginner’s Guide To Ireland’s Weather

iWeather Online's Martin Davidson writes: I am going to write a few articles on the weather's related terms and sayings and what drive's Ireland's weather, I am by no means an expert but have had an avid interest in all going's on with the weather on our fascinating planet for over 25 years. I will try to present everything in laypersons terms and help all with understanding of the very complex words and models of interest in forecasting our weather. 

PART 1: Ireland’s Weather

Gulf Stream:  It is somewhat unusual that for a nation with such a northerly latitude we have a mild climate (mostly).  The reason for this? The Atlantic has a strong stream of warm water "called the gulf stream" that originates around the tip of Florida ("the whole system originates of the west coast of Africa and meets at the tip of Florida, it then "travels across the Atlantic, it then splits in two with one side heading up north and one heading down south).  This water is a lot warmer (it is basically a river flowing through the Atlantic) and hence gives much of northern Europe a milder climate than it should for such a latitude.
The gulf stream’s northern section is also known as the North Atlantic Drift and is only a small part of the "thermohaline circulation",  a large complex system that travels around the globe's oceans.  There are signs that the thermohaline circulation is being slowed down while there also is a school of belief that the gulf stream is cooling.  This would have a huge impact on northern Europe's climate and Irelands mild climate would cool significantly.  Is this global warming or just the natural cycle of the mother nature itself? We probably will not really know in our lifetime, but there are signs that our winters are becoming cooler.

Jet Stream: Jet streams are high level air that flow from west to east all around the globe. They are  caused by the earth's natural spinning on its axis and the heating of the atmosphere (caused by solar radiation).

The position of jet streams position can be altered to either more northerly or southerly while they can also split. The jet stream is usually a dividing line between warmer and colder air.  The jet stream is also a significant contributory factor to our often wet and windy climate. 

Ireland sits very near the boundary of colder polar air and warmer tropical air, add in the gulf stream bringing in humidity and we are in a "Convergence Zone", meaning while temperatures are usually stable the air is not, hence all the dreary wet weather Ireland sees. Many of our weather systems move in from the south west and as such the south west and west get a lot more rain than the east and south east.  The reason behind this is the large mountains areas in the south west and west; as the cloud moves in it has to rise to clear over the top of these mountains and as it does so it releases a lot of the moisture meaning less rain fall for those fortunate to live further to the east and south east.

In part 2 I will explain briefly and in laymen terms how to read weather charts and models.

More detailed information on Ireland's weather is available from the 'Irish Weather' tab at the top of this page.