I'll tell you what it means. You take-off VFR. You plan to land somewhere and the forecast has to give you reasonable confidence you can do that VFR. You make this sound bizarre and unfathomable, but hold on.....it's what you do flying VFR. That's why it's an Enroute qualification.
Let’s examine how this might work in the UK.
Firstly, the TAF is not going to tell you “if almost certain VFR conditions” will exist at your destination.
It will tell you if the cloud is scattered, broken or overcast – at any rate so far as the lowest layer is concerned. It doesn’t necessarily tell you much about higher layers.
Now for the VFR pilot that is all fine and Dandy. His intention is to stay below the lowest layer. He doesn’t really mind if the scattered turns into broken or the broken into overcast. What he does care about is that the Met boys don’t get the base wrong and he finds himself squeezed between the terrain and the base.
The IMC pilot’s modus operandi is a little different. Our man is worried about getting himself up into the airways. He is not too bothered what he finds in the airways because within reason he can now fly through cloud. However he wants to ensure his let down is “almost certainly going to be VFR”. The forecast was scattered at 1,000 feet so that seemed good enough. The trouble was the met boys didn’t tell the clouds who decided a little more organisation was called for – scattered became broken, how often have we seen that. Now our man is flying the approach, but what should he do – he feels comfortable following the procedure, but there are more than a few pesky clouds in the way. Perhaps he will dodge around and between them – yep that should be fun. Trouble is no one told the radar controller that EASA had just invented the dodge and weave approach.
That is a simple example. In the real world there are all sorts of different examples why who ever dreamed this one up has no idea what they are talking about. The funny thing is they don’t even realise that some at EASA get exactly what they wish – the effective end of the IMC rating and no meaningful change to the IR. Its brilliant – Sir Humphrey at his best.
God save us if if we end up with this sort of silly instrument en route rating.