The focal point for storms has been edging slightly west with each new set of model runs... this hasn't been seen for many, many years, and the reason why is because what we're looking at is a different breed of plume to those of the past 6 years or so;
Plumes in recent years, and also the one early in June this year, have featured a relatively weak ridge across Europe and a trough either to the south or west. The trough progresses N/NE then NE over the ridge, and tends to do so a little more quickly than the models initially predict, resulting in a shift east in the plume and region of greatest thunderstorm potential.
This one, however, features a robust block building to the NE, and this is something the models tend to underestimate at range, with corrections being towards more of a push from the east which then shifts the plume and highest thunderstorm potential west.
It's also the reason for temperatures in the S/SE not being knocked down below the mid-20's after the plume has cleared, and it currently looks like the block will then combine with a ridge from the SW to serve as a catalyst for some appreciable home-grown heat 
If you have any problems or queries relating to TWO you can Email
[email protected] https://twitter.com/peacockreports 2023's Homeland Extremes:
T-Max: 30.2°C 9th Sep (...!) | T-Min: -7.1°C 22nd & 23rd Jan | Wettest Day: 25.9mm 2nd Nov | Ice Days: 1 (2nd Dec -1.3°C in freezing fog)
Keep Calm and Forecast On