Goed stuk Wietse. Op basis van de kaarten is dat idd het meest waarschijnlijk en toch..
Ik vond nog een aardige visie van een van de experts (hij stelt oa weersverwachtingen van deze site op) van netweather. Vanmiddag had ik 'm al eens geplaatst.
The track of the weekends low and how it interacts with the LPs to our south west are crucial and a real headache for the models, this coupled with the modelling of the mid Atlantic high is making me suspicious of all output past that point. My guess is, that rather like the no show super storm, the low to the south west may not make it as far north as current output suggests.
The change is coming through greater flow over the top of the mean ridge. The coupled ocean-atmosphere system suggests that the ECM this morning blows heights to the north too fast and is an outlier. If so, that low to our SW is unlikely to have much of an impact and is incorrectly modelled at present.
The GFS Ensemble mean continues to suggest below average conditions for some time to come, not as much as in the last week or two, but still below average with snow potential.
The principle behind the upper low working its way north-east towards the UK is predicated on the block weakening and pulling back west.
The models may well be underestimating the persistent, particularly in the mid latitudes so the scenario being advertised by the 06z GFS comes into play where the upper low begins to eject shortwaves eastwards across the Channel and northern France leading to a significant undercut of cold air ahead of the fronts. Potential for a very snowy period if that's the case for much of central / southern England to start.
However, as per last week, the upper low may come under pressure and any westerly intertia may end up south of the UK. There is of course the other scenario whereby the upper low becomes one huge 'trigger low' for another renewed northerly outbreak.
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