On the afternoon of November 1st ECMWF uncovered a technical problem that had been affecting the integrity of the some probability charts on the ECMWF web site (ecCharts output was not affected). This had happened for runs from all data times from 23rd October 12UTC.

The charts affected were the clickable probability charts from the ensemble (ENS), for max wind gust and for total precipitation.

On some charts the corruption was clear. On others it was not. Users must assume that all charts in these categories, for all areas, were incorrect.

We sincerely apologise to all users for this issue, which was discovered on the afternoon of 1st November. Following discovery we acted swiftly to rectify the problem and all output beginning with the 00UTC 2nd November runs is correct again.

During today (2nd November) ECMWF will be systematically over-writing all the corrupted charts, from the earlier data times, with corrected versions. We expect that this process will have completed by about 18UTC.