"The end of January and start of February saw the coldest spell of the winter as a polar maritime air
mass dominated and low pressure systems moved to the south of Ireland.
This air mass is mostly just another form of polar maritime air
, however it has a longer sea track that initially takes the air southwards over the North-Atlantic, then north-eastwards across the UK.
"At the moment it is called a Polar Maritime Air
Mass which is coming from beyond Iceland and Greenland.
Liam Dutton says: "As well as turning unsettled, it'll turn colder due to polar maritime air
coming from Greenland.
"We will be dominated by Polar Maritime Air
, feeding down from Greenland and Iceland."
"During the latter part of next week we also see some deep Atlantic lows developing and pushing polar maritime air
"The weather pattern from Wednesday will be very similar to two weeks ago with a very unstable polar maritime air
mass dragged all the way from North West Canada."
"Returning polar maritime air
is such an unstable condition and it basically means air returning from the polar regions which is very unstable.
"This is going to introduce cold polar maritime air
originating around Greenland.
A spokesman said: "With a cool polar maritime air
mass affecting the UK, it will also turn chilly overnight."
A Met Eireann spokesman said: "A strong westerly air flow will cover Ireland this week with a cold, polar maritime air
mass bringing lots of showers, many of which will be wintry.
The Met Office said Polar maritime air
from Greenland and the Arctic Ocean would make 11-13C highs today feel like 7-10C in cold breezes.