Plot a validation sample after long rollout

[sahahner]

Is your feature request related to a problem? Please describe.

When wanting to evaluate the stability of the trained model, we might want to have a look at a long rollout for a validation sample.

Describe the solution you'd like

For the validation sample, for which we already plot the forecast and forecast errors for the rollout steps used during training, plot the forecasts for selected longer rollouts.

Describe alternatives you've considered

Evaluating longer rollouts is done in inference right now and uses a different tool.

Additional context

No response

Organisation

ECMWF