Long Range Weather Forecast For Ireland (19 February 2021)

TRENDS for the week of 19 to 25 Feb 2021

-- Temperatures will average about 2 to 3 deg above normal values.
-- Rainfall will average 50 per cent above normal, with higher amounts possible in the south.
-- Sunshine will average near normal, improving later in the week.


TODAY the heaviest rain and strongest winds have just about peaked across the south and east, and while it will remain blustery and showery, there should be some improvements to conditions especially by the afternoon by which time it should be less windy with only isolated showers. About 15 mm of rain has fallen in some areas and 10 to 15 mm additional could fall in the next few hours. In a few parts of west Munster this could lead to localized flooding from small stream runoff overflowing. Highs today around 12 C and winds southerly, currently in the 70 to 100 km/hr range in places, moderating to 50 to 80 km/hr by afternoon.

TONIGHT will see further isolated showers and moderate southerly winds, mild with lows 6 to 8 C.

SATURDAY will be quite mild with southerly winds reaching 70 to 110 km/hr at times by mid-day and afternoon, except near the west coast where the centre of low pressure moving north will have slacker gradients and locally winds could be easterly to northerly as the low tracks past in the afternoon. This low may generate a blustery cold front with squall line potential although current guidance keeps that potential non-severe. Highs near 11 C except closer to 7 C in some parts of the northwest. Temperatures will fall gradually later in the day.

SUNDAY will become more pleasant with some sunny intervals and generally more moderate wind speeds in the 40 to 70 km/hr range. Lows near 4 C and highs near 10 C.

MONDAY will have a rather chilly start with morning lows 2 to 5 C, light winds will give way to increasing southerly winds of 70 to 100 km/hr by late afternoon, and a peak near 80 to 120 km/hr is possible overnight as a strong frontal system crosses the country with heavy rainfalls returning for much of the overnight period, lasting into TUESDAY when it will continue windy with heavy rainfalls tapering gradually to showers, winds veering to southwest 60 to 90 km/hr before finally abating late in the day, with temperatures steady near 9 C. There appears to be potential for 40 to 60 mm rainfall totals in parts of the south and possibly elsewhere in the two-day life cycle of this storm system.

The rest of next week then looks more settled, with guidance somewhat split on the details. Some guidance builds up strong high pressure right over Ireland for several days near the end of the month. Other guidance prefers to keep the high pressure over France and maintains a gentle southwest flow for Ireland that becomes stronger towards the last day of the month. Either way it would likely be around 10 C with some sunshine each day, but the more mobile option would include some chances for showers along weak frontal systems. The colder spell that had been anticipated is now moved back into early March and takes on more of a northerly look, as earlier this high had been expected to be further north to promote cool easterly flow. Looks like we're getting back to the familiar guidance tendency to present and then remove from view cold spells about two weeks into the future.

Peter O'Donnell for IWO