TRENDS for the week of 22 to 28 Jan 2021
-- Temperatures will average 1 to 2 deg below normal, a blend of cold to
around Monday (3-4 below average) and milder after Tuesday (2-3 above
normal then).
-- Rainfalls will average near normal values and there may be significant amounts of snow in the precipitation.
-- Sunshine will average near normal values.
FORECASTS
TODAY will be partly cloudy with longer sunny intervals in the east than
elsewhere, rather frequent mixed wintry showers feeding in from the
west and northwest, changing readily to snow over higher parts of the
north and west, but the snow line will also be falling to lower
elevations by afternoon and evening. Winds west to northwest 40 to 70
km/hr, adding some chill to daytime highs near 4 C in most areas, 7 C
near west coast.
TONIGHT will see some clear intervals developing, as wintry showers
become confined to Atlantic coastal counties. Lows -4 to -1 C.
SATURDAY will start out clear and cold in many areas, then will become
overcast with intervals of sleet or snow developing. These may become
rather heavy across the midlands and parts of Munster and Leinster by
evening and into the overnight hours, 5 to 15 cm snowfalls are possible
although some lower elevations could see mixing and lose some of that
total accumulation. Highs 2 to 5 C.
SUNDAY there may be a second wave of mixed wintry precipitation after
some breaks in the overcast around mid-day and it will remain quite
cold, lows near -2 C and highs near 4 C.
MONDAY will have some morning frosts and a slow increase in temperatures
later in the day but as rain hits the west coast during the night it
may turn to sleet or snow inland for a time until Tuesday morning,
temperatures starting out below freezing (lows near -3 C) and rising to
the 3-6 C range.
TUESDAY will turn slightly milder as rain pushes in slowly, turning
sleet or wet snow over to rain eventually in parts of the inland north.
Lows near 2 C and highs near 7 C.
The OUTLOOK for the rest of the week is milder with occasional rain and
strong southwest winds; timing is a bit uncertain with a number of
separate systems expected at roughly 24-36 hour intervals; the strongest
of these now appears likely to be the "hidden low" I mentioned as
models pick up the energy peak timed for about Thursday night into
Friday.
Mild conditions may turn back to cold and snowy before the end of the
weekend of 30-31 Jan, and the first week of February is looking rather
cold in general with high pressure developing to the northeast, and
winds turning easterly as a result. None of this is entirely "carved in
stone" this far ahead, so stay tuned. This winter is probably far from
done.
Peter O'Donnell for IWO