These Met Office models were never designed to be interrupted, and BOINC has several ways to do just this, to help with running other projects. So it will help to turn off these interruptions.
Plus some other ideas.
(These settings can be found, and used, on the project's web site in your Account preferences, and also in the menu of the BOINC manager. The latter settings take preference over the former settings.)
Leave tasks in memory while suspended? Set this to yes, to minimise the amount of recalculations needed each time the model gets interrupted after a switch to a different project.
Suspend work if CPU usage is above (Used for reducing heat buildup.) But NOT a good idea in cpdn. Set it to zero to turn it off.
Instead, limit the number of cores available for models. If necessary, use the Venues setting to use a different lot of options here, to what you use on other projects.
Use at most
Can be used to reduce CPU heat
Again, not a good idea, as it works by turning the tasks on and off in different proportions.
Set this to 100%