In FI ...you see a very good example of cold blocking, In looking at the surface pressure chart below you would think the atlantic would push East, with ease
Until you see the cold 850hpa temperatures that are just to the East of the UK,
cold air is denser than warm air, so the warmer air finds it a lot harder to push through the block HP.
Most on here know this, thats why we all love a good Easterly because when the cold air is in place, in can take a long time to get rid of, if not weeks.
And when the atlantic tries to push East against the cold blocking, HERE in the UK we can have some very good snowfalls, as you can see below.
Just a note, this is a simple guide and just for folk that don't fully understand what blocking is about..... hope it helps.