From the Met Office regarding snow in Northern Ireland
'The number of days of snowfall and snow cover varies enormously from year to year. At many places in the last 50 years it has ranged from none at all in several winters to in excess of 30 days during the winters of 1962/63 and 1981/82'
The Met Office confirm that Northern Ireland doesn't get snow every year, let alone every November
The chances of that chart verifying, given it's 15 days away, is slim to say the least. For all we know we could be having a strong North-Easterly flow by then
Parts of Scotland could be getting snow to low levels in just 8 days if the 6z verifies.
Best chart of the 6z though is in 9 days, with parts of England possibly getting snow, and Wales and Northern Ireland too