Climate statements for November and Autumn 2018
November was dull and wet in the south and east
After a chilly start, much of the first three weeks of November were relatively mild. Low pressure centred to the northwest of Ireland was a constant feature between the 3rd and 15th. An active North Atlantic jet stream fed weather fronts and troughs up over Ireland from the south and southwest, sometimes stalling over the east of the country as they pushed against a blocking high pressure system over Northern Europe. This gave rain or showers on most days with heavy widespread rain and strong winds on the 9th. After the 15th, the blocking high pressure system over Northern Europe began to move westwards over Scandinavia pushing the Atlantic weather fronts away from Ireland. This introduced a progressively cooler, drier southeasterly then easterly airflow over Ireland up to the 19th. The easterly flow became more unstable after the 19th, with showers or longer spells of heavy rain or hail principally to the east and south. From the 27th to the end of the month, the Atlantic influence returned with a succession of weather fronts and active low pressure systems, including Storm Diana on the 28th, traversing the country bringing heavy rain or showers and gales at times.
Full report here
Autumn was cool and dry overall
September and October were cool and dry. High pressure in the first week of September gave way to a mainly Atlantic dominated westerly airflow for the middle of the month. Two named storms Ali and Bronagh brought disruptive violent storm force winds and heavy rain during this period. It settled down again for the last week with high pressure dominating. High pressure continued to keep most of the first week of October dry and settled. It became more unsettled during the second week. An exceptionally deep area of low pressure associated with Storm Callum moved north close to the West coast, bringing the windiest spell of the month. The second half of October was mostly cool and settled with high pressure nearby. A northerly airflow towards the end of the month brought the coldest period of the season. November was mild overall with above average rainfall in the South and East for the first time since April 2018. Low pressure dominated the first half of the month with numerous Atlantic weather fronts crossing the country. A continental easterly airflow developed mid-month and lasted for nearly two weeks. The month finished unsettled with Atlantic low-pressure systems, including Storm Diana, bringing heavy rain and strong winds.
Full report here