Januarys 1969 and 1984

[North-Easterly Blast]

I have talked about these months before, but I think an analysis should be done about why January 1969 despite being a very negative NAO month ended up well above average in terms of CET, and was a dissapointment in an otherwise cold winter, and on the other hand, why January 1984, despite being a positive NAO month ended up much colder than Jan 1969 and had such a cold, snowy second half, and the two compared together.

My analysis of the charts is that, in January 1969, it was a negative NAO setup, with frequent appearances of the Arctic High and pressure frequently high over Greenland, but the synoptics just did not quite play ball for cold weather in the UK, as low pressure was frequently stationary to the west of Ireland keeping the UK in "no man's land". January 1969 is a classic example of how a negative NAO is no guarantee of colder conditions in the UK.

My analysis of the charts for January 1984, is that the first half saw quite mild SW'lies with a couple of topplers, but by mid-month the Azores High moved further west than normal, allowing depressions to take a NW-SE track leaving the UK to the north of the polar front despite a zonal flow during the second half. Although the Arctic High did appear well to the north of Scandy towards the 23rd / 24th it was never in a position to give the UK a real northerly / easterly, and yet that period was so cold and snowy for the UK. January 1984 is the classic example of how a positive NAO can still bring colder conditions to the UK.

I would welcome insights in the key to understanding why January 1969 was so mild despite a negative NAO compared to why January 1984 was so much colder despite a positive NAO.