Monthly forecasts can at times provide an insight into weather patterns in the month ahead. However, they should not be used for specific planning purposes as they have generally low skill compared with the 10-day forecast. This is because forecasts beyond one week become increasingly uncertain due to the chaotic nature of the atmosphere. Monthly forecast explained.
MONTHLY FORECAST, ISSUED 1600 FriDAY 16 APRIL 2021
Week 1 (Monday 19 April to Sunday 25 April)
High pressure to the north of Ireland looks to steer in an east to southeasterly flow, conditions are expected to be drier than normal with slightly above average temperatures in most parts of the country, closer to average along the east and southeast coasts owing to that predominant on shore breeze. With high pressure dominating the forecast period, there is no strong signal of significant hazards, however night frost will most likely remain a risk through the period.
Week 2 (Monday 26 April to Sunday 02 May)
With High pressure set to weaken and pull away to the northwest Ireland will lie in an east to northeasterly airflow brining the temperatures closer to or slightly below average. It will remain mostly dry however. Similar to the previous period, hazards look limited yet night frosts cannot be ruled out.
Week 3 (Monday 03 May to Sunday 09 May)
A weak signal of upper level high pressure over the Iberian peninsula with surface low pressure to the south west will feed a weak southerly flow towards Ireland. This will likely bring a return to near or slightly above average rainfall, especially to the west. Temperatures will remain close to average for the time of year. With increased rainfall coming from the south there is a chance of some heavier precipitation at times however currently there is no strong hazard signal associated with that. Generally conditions look a little more unsettled, however nothing exceptional.
Week 4 (Monday 10 May to Sunday 16 May)
Very little change to the previous week with the upper level high pressure over the Iberian peninsula shifting a little further west and lowers surface pressure to our northwest. The flow will be generally out of the southwest however it looks to remain weak with rainfall totals generally near average to slight above along western fringes and temperatures close to average for the time of year. There is little in the way of hazard indicators through this period.