TRENDS for the week of 8 to 14 Jan 2021
-- Temperatures will average 2 to 4 deg below normal, with a slow moderation towards normal late in the interval.
-- Rainfalls will average 50 to 75 per cent of normal, most of which will occur around Tuesday into Wednesday next week.
-- Sunshine will average slightly above normal in many areas.
FORECASTS
TODAY will be partly cloudy with some areas seeing plenty of sunshine, others rather cloudy if they are located near scattered bands of wintry showers drifting south from the Atlantic west of Scotland. These wintry showers may contain mixtures near coasts but will readily turn to sleet or snow inland. Some parts of the east coast may be brushed by southward moving wintry showers but many of those could stay just offshore making for some interesting cloud scenes near the Wicklow coast. Very cold with highs 1 to 4 C.
TONIGHT will be very cold also with clear skies promoting some local freezing fog banks in valleys, otherwise fairly clear except for any isolated wintry shower bands which should die out by midnight. Lows -4 to -7 C inland but slightly milder on some outer coasts.
SATURDAY will be the slow start to a transition away from the cold for a while, but with only a weak westerly flow available, the cold air may be hard to move out of many eastern and central counties. It will likely warm up a little faster in west Munster, west and north Connacht and west Ulster where highs could reach 7 C, but further east, highs of 2 to 5 C are more likely.
SUNDAY continues this slow process under partly cloudy skies, a less severe frost to start in some places (lows -4 to +2 C) then highs reaching about 9 C in the west, 6 C in the east. The warming trend will be largely dry but there could be scattered outbreaks of drizzle or light rain in the northwest at times.
MONDAY will also be a bit milder in the south but there could be a slight relapse to colder temperatures in the north as a weak disturbance turns winds around to the northwest briefly there. Scattered wintry showers could follow. Highs will be in the range of 4 to 8 C from north to south.
TUESDAY and WEDNESDAY are looking somewhat milder again, although in east Ulster and north Leinster the colder air from Monday's incursion may try to hang around most of the day. Eventually some steady rain is likely to follow by Wednesday. Highs in the south and west near 10 C both days, east around 8 C, north 5 to 7 C.
The OUTLOOK beyond mid-week is for slightly colder air to return in a variable wind regime at first, followed by an easterly that might pull in significantly colder air at some point around the 16th-17th. Too soon to be very reliable guidance but some models are showing the potential for a frontal boundary event near or through Ireland in this period meaning that some areas (most likely north and east) could see some snow.
-- Peter O'Donnell for IWO