Long Range Weather Forecast For Ireland (18 January 2021)


TRENDS for the week of 18 to 24 Jan 2021

-- Temperatures will average 1.5 deg below normal, a blend of 3-4 deg above normal to early Wednesday and 4-5 deg below normal thereafter.
-- Rainfalls will average near normal to 25% above normal, and most of that will fall on Tuesday and Wednesday (some will be sleet or snow).
-- Sunshine will be near normal by end of the interval, despite mostly cloudy skies for the first three days.


TODAY will be overcast with outbreaks of light rain starting in the southwest by afternoon, spreading somewhat further north and east. Another area of light rain may brush parts of the northwest coastal areas. Highs 7 to 9 C.

TONIGHT will be mild with fog and occasional rain, 5 to 15 mm by morning. Lows 7 to 9 C except 3 to 5 C in parts of Ulster. Winds in most areas will become southeast to south 40 to 60 km/hr, backing to northeast in parts of Ulster.

TUESDAY will see rainfalls of 10-20 mm additional, with winds remaining moderate southeast to south 50 to 70 km/hr for most, easterly 40 to 60 km/hr in Ulster. Foggy at times especially over higher terrain, highs 10 to 12 C. Bands of heavier rain likely in central counties towards south Ulster, totals may reach 50 mm there by Tuesday night with flood risks in poorly drained areas.

WEDNESDAY the rain will continue but will begin to turn to sleet and wet snow, from early morning in parts of the north, mid-day in Leinster, with snow starting to accumulate just before ending late in the day. Winds becoming northerly 40 to 60 km/hr, temperatures near 8 C in the morning in the southeast, otherwise 2 to 4 C most other areas, and those readings will reach the southeast by afternoon. Around +1C by evening with slushy accumulations on lower ground in Leinster, 5-15 cm snowfalls on hills.

THURSDAY will become windy and colder, with bands of wintry showers, snow the main component inland on hills, sleet at somewhat lower elevations and rain/hail/sleet mixtures near sea level. Some sunny intervals between the bands of showers, winds northwest 80 to 110 km/hr. Morning lows near -1 C and highs 1 to 3 C except 4 to 6 C near Atlantic coasts.

At this time parts of northern England and eastern Scotland will have near-blizzard conditions as the low intensifies off the coast of eastern Scotland.

FRIDAY will be sunny and cold with isolated wintry showers, not as windy, lows near -3 C and highs near 4 C.

The outlook for next weekend is uncertain, cold air will try to hang on but could be quickly replaced in the south by milder air near 8 C and rain, leading to snow or sleet in parts of central and northern counties. There is also a slight risk of snow in the south on Saturday morning from a weak low expected to track south of Ireland into France.

That sort of pattern may repeat from time to time in the following week, with quick temperature changes as waves of low pressure move through Ireland from west to east in a rather active jet stream.

-- Peter O'Donnell for IWO