>>What you've related makes zero (nada, zilch) sense to me.

It's going to take a little bit of time (if it verifies, it will happen late Saturday night or early Sunday morning). Either a piece of the upper energy (low pressure mirroring a trof split), or the whole system is going to get pushed back southward, then Southwestward. There is model support for both ideas. Then again, you can find model support for about 10 other scenarios too. But we're going to have to watch. The 12Z UKMet from Friday kind of showed the scenario at 500 mb.

UK Met 500mb Vorticity

It might not make sense to you, but if you researched the different possibilities (and granted, I don't go around interpreting the 200/500/700mb charts every day), you would have seen the potential for what the UK Met is doing (or was at 12z).

Steve