Long Range Weather Forecast For Ireland (9 January 2021)


TRENDS for the week of 9 to 15 Jan 2021

-- Temperatures will average 2 to 4 deg below normal, despite one or two days around mid-week pushing above normal slightly.
-- Rainfall will average 50 to 75 per cent of normal, most of it taking place around Wednesday.
-- Sunshine will average slightly above normal.


TODAY will start out bitterly cold with widespread wintry sunshine but some local ice fog patches possible. With very light winds, the air mass will not allow any milder air to mix down in many areas, so temperatures will only gradually edge back towards freezing and highs near 2 C. Closer to the west coast however, there will be a more significant warming trend with highs reaching 7 C. Some scattered outbreaks of drizzle will occur in the northwest but it should remain dry although perhaps icy in most other regions.

TONIGHT there will continue to be some frosts although not as severe, with lows -5 to -2 C, staying closer to +1 C near west coast. Skies will be clear to partly cloudy, with some patchy overcast and drizzle in the north.

SUNDAY will become partly cloudy to overcast with some light rain in the west by evening. Highs near 4 C in the east to 8 C west.

MONDAY will be overcast with showers or intervals of light rain, temperatures steady 4 to 7 C (slightly higher near Atlantic coasts), and it may begin to turn a bit colder again in Ulster and north Leinster by evening.

TUESDAY a wedge of cold, dry air over Britain will perhaps influence east Ulster and north Leinster where highs may be capped at around 5 C, but further west, mild air will slowly push in from the west, raising temperatures to the range of 8 to 10 C, with occasional light rain developing overnight.

WEDNESDAY will become quite mild in all areas with highs 10 to 12 C, and about 10-15 mm rain is likely. This will push off to the southeast during the afternoon, and slightly cooler air will return by the evening.

THURSDAY will be partly cloudy to overcast with lows near 1 C and highs near 6 C.

FRIDAY will be overcast with lows near -1 C and highs near 7 C.

The outlook for next weekend is for another wedge of milder air to arrive on Saturday, with some rain likely, highs near 10 C, then a bit cooler by Sunday (around 7 C). The evolution beyond that is somewhat in doubt, quite a bit of the guidance has colder air building in from the north around the start of the week (18th Jan), other sources suggest mild regimes holding on for a while with cold massing just to the north. Either way there are prospects for a return to very cold temperatures at some point towards the end of January.

Peter O'Donnell for IWO