Even more alarming is the lead-up to the 'jump at Warp 9'.
VA charts for the preceding several days had all shown a consistent progression towards the supposedly-accurate chart for Monday 0600. OK - so maybe the data being fed into the VA modelling software was based on weather forecasts that turned out to be inaccurate.
But hang on a minute.....
Once the actual weather yields real data (wind-speed, mass-air-flows, etc.), then the VA model should be routinely re-run, to correct the effects of incorrect weather forecasts, and then only those results used for further VA movement predictions. Otherwise, there is every likelihood of errors that 'self-amplify'.
It looks possible that this was not done, leading to the chaos on Monday morning: accumulating errors leading to a series of increasingly inaccurate charts, over several days. Then comparison data from an ash research flight (when???) became available, and sudden and massive changes were unavoidable. What other explanation fits the facts?
It would be OK if this was just a bunch of boffins doing basic research. But it seems to me that the Met Office has lost track entirely of the massive cost and other consequences for airlines and customers when errors occur. And quite apart from the noted problem of VA actually being present in the white bits!