It's very difficult to forecast a sting jet from the synoptics available to the public. The MetO would have more up to date info coming in, so they could anticipate this. On a few occasions, when storms have good timing with the FAX chart updates, you can sometimes see a back-bent occlusion on them- which is usually the sign that a sting jet occurred. The term tends to get banded around a lot now, as soon as a deep-ish low develops and heads towards the UK.
Just to add; The strongest winds will be on the southern flank, so if one were to occur, it would be likely that Benelux would take the brunt of it, with a low risk of the far SE corner catching some of it.