TRENDS for the week of 12 to 18 June, 2021
-- Temperatures will average near normal to 2 deg above normal, with the trend gradually declining from above normal values at first to below normal by end of the week. Eastern regions will be more likely to average above normal mainly because they will have considerably warmer temperatures in the first half, all regions will fall to about 2-4 below normal by about Friday of this coming week.
-- Rainfall will gradually increase to about 50-75 per cent of normal values in parts of the west and north but a lot of this rain is expected to dry up before reaching the east where 25 per cent of normal might be the limit.
-- Sunshine will average about 75 per cent of normal values with closer to 50 per cent likely in cloudier coastal south, west and northwest.
-- Winds will pick up to more moderate values at times.
FORECASTS
TONIGHT will be overcast and muggy with intervals of light rain across parts of Ulster, Connacht and the midlands. This will amount to 3-5 mm in some places. Some fog or mist likely. Lows 13 to 17 C.
SUNDAY will once again turn somewhat brighter after a cloudy start in most places, and it will reach similar temperatures with highs 20-23 C for most, 23-25 C in a few spots near the east coast. Another front will develop and move into the west and north with occasional rain lasting overnight. This may have somewhat better chances of reaching the east and south at times overnight into early Monday but amounts will range from 5-10 mm in the north to trace values in some parts of the southeast. Quite humid making the relatively moderate temperatures feel oppressively warm to some.
MONDAY will then see this rain clearing away with a slightly fresher and less humid air mass with westerly breezes and some intervals of bright sunshine developing. Morning lows 14 to 18 C and afternoon highs 19 to 22 C.
TUESDAY will continue warm and dry for many especially the east and south, as a more significant front develops near the west coast and moves slowly further inland during the afternoon. Sporadic outbreaks of rain will develop with a rather sharp temperature drop expected in western regions. Morning lows 13 to 17 C, afternoon highs will reach 20 to 23 C in the southeast and east but readings near 19 C will fall to mid-teens in the west.
WEDNESDAY will have variable amounts of cloud, northerly breezes and some outbreaks of light rain possible, but heavy rain will form over France along the stalled out front and that rain will spread into parts of Britain where 20 to 40 mm amounts are possible. Ireland will likely see much less than that and some parts of the southeast may remain dry. Lows near 8 C and highs near 18 C in the south, 14 C in the north.
THURSDAY and FRIDAY look like being quite cool days with scattered outbreaks of light rain in rather variable north to northeast winds, but with the tendency being for more rain to fall in the north than elsewhere, and the southeast could remain largely dry. Lows each day 6 to 9 C and highs 13 to 17 C.
SATURDAY (19th) will become overcast with rain becoming heavy at times and moving into all regions (this is a day beyond the scope of the "trends" forecast above). Amounts of 10-25 mm are projected for this front with strong and gusty south to southwest winds veering westerly, temperatures in the 15-18 C range.
Even cooler air is expected to flow in from the northwest after that front passes by Sunday and Monday (20th-21st) and temperatures could be back into the near-record cool category by then (similar to some parts of May). A conservative estimate would be lows of 5-7 C and highs of 13-16 C. Some places might see lower readings than that. So as I was mentioning yesterday, it looks like quite a reversal in the weather regime over the space of about ten days.
Peter for IWO.
Photo: Lough Ree, Westmeath.