Tuesday, 12 January, 2021
Forecasts for Ireland
TRENDS for the week of 12 to 18 Jan 2021
-- Temperatures will average 1 to 2 deg above normal values, although dropping to colder levels at end of the interval.
-- Rainfall will average 25% above normal in some parts of the northwest and central counties, to as much as 50% below normal near the south coast. Much of the heavier rainfall will occur tonight and Wednesday morning.
-- Sunshine will average near normal values.
TODAY will see a moderate to heavy rainfall zone setting up from north Connacht southeast into the midlands, and extending eventually into Leinster. East Ulster and north Leinster may remain largely dry although overcast, and the south coast will only see lighter rainfall in showers later in the day. It will be mild in most places, although rather cool in the northeast, at least until later in the afternoon, with highs near 7 C there, otherwise most places will probably reach 11 or 12 C. About 30-40 mm of rain will fall in the heavier rainfall zone by late tonight.
TONIGHT will see heavy rain continuing in the northwest and central counties for a time, with somewhat heavier rain (than earlier) breaking out also in other regions. Foggy and mild with lows generally 8 to 10 C.
WEDNESDAY will start out quite mild with the rain ending, then a gradual clearing trend will develop from the west, although it may not reach the east coast before afternoon. Temperatures steady 10 to 12 C then falling slowly.
THURSDAY will be partly cloudy and considerably cooler with lows near 4 C and highs near 8 C.
FRIDAY will have clear skies to start, with frosts likely, lows near -2 C. Then it will begin to warm up again, rather slowly, in a weak southerly flow, although more blustery near Atlantic coasts where rain is likely to spread in. Highs will range from 6 C east to 10 C west. The rain will continue overnight, becoming more showery by early Saturday.
SATURDAY will be partly cloudy to overcast, windy with passing showers, winds westerly 50 to 80 km/hr, lows near 5 C and highs near 8 C.
SUNDAY will be partly cloudy to overcast with a few showers, possibly becoming wintry in some parts of the north, winds turning more northwesterly 50 to 80 km/hr, lows near 4 C and highs near 7 C.
The OUTLOOK for next week is challenging (to the forecast models, each one comes up with a somewhat different solution) -- the general theme is cold to very cold, with a moderate to high risk of snow or sleet towards the end of the week. The cold may eventually become severe according to some guidance, but at this point, I'm only committing (in the forecast) to a moderate cooling trend with highs to drop to around 3-6 C and night frosts likely to return, with at least mixed wintry showers at times next week, and possibly a significant snowfall. Details on all this will no doubt come into better focus by about this coming weekend.
My local weather has turned snowy as expected, so far about 8 cm and it's coming down moderately at this late hour, probably on the way to 20-30 cm totals. Temperatures have been just around freezing so this could start to mix with rain at some point during the storm, as the warmer Pacific air comes in over top of us to create chinook conditions east of the Rockies by mid-week. At that point much colder air will hit my region in the wake of the low pressure system.