TRENDS for the week of 5 to 11 May, 2021
-- Temperatures will average 1 to 3 deg below normal values, somewhat milder around Saturday.
-- Rainfalls will average near normal values, most of the rain expected will be around Sunday-Monday.
-- Suinshine will average 50 to 75 per cent of normal, winds will be generally moderate.
FORECASTS
TODAY will be partly cloudy in most regions, somewhat more overcast in the north where more frequent showers are likely, and some of those could turn wintry on higher terrain. Elsewhere showers will likely be mostly rain with some hail and the risk of thunder. Amounts for most will be slight, 1-3 mm. Quite cool for early May, highs 7 to 10 C in the north, and 10 to 13 C in the south.
TONIGHT will continue partly cloudy to overcast with isolated showers, and scattered frosts where skies clear for any length of time, lows -2 to +2 C.
THURSDAY will be partly cloudy with showers, cool and breezy (northerly 40-60 km/hr), highs 7 to 12 C.
FRIDAY will be partly cloudy with only a few isolated showers, and longer sunny breaks for some, lows -3 to +2 C and highs 10 to 13 C. Rain will spread into the southwest by late afternoon or evening.
SATURDAY will turn somewhat milder in the southeast, with occasional rain and variable cloud cover, highs reaching about 14 C there. The west and north will remain overcast with outbreaks of rain developing, 5 to 10 mm likely, and highs 12 or 13 C.
SUNDAY will see similar conditions but rain will be more persistent and will slowly spread further east, 10 to 20 mm could fall especially in west Munster and Connacht. Highs 11 to 13 C.
MONDAY and TUESDAY will probably see a gradual cooling trend, the speed with which temperatures fall depends on whether the weekend low spins around a couple of times or keeps plodding along to the northeast, if it does the latter then cooler air can begin to spread back in from the north a little faster. Temperatures will be down at least a degree or two each day, and could be back to the current levels by Tuesday. Some showers are likely in north to northeast winds.
Around mid-week high pressure will build up and this could lead to sharp frosts at night with clearing skies, but days should be tolerable with the light winds and highs around 12 to 15 C. The guidance is a bit scattered on how fast this high breaks down and there could be several dry days or possibly a return to rain by about Friday into Saturday. The longer term looks rather variable with temperatures on either side of normal at times, but always with the threat of one more significant cold spell developing.
Peter for IWO