Our first 2019 summer forecast

We are now ready with our first ever in-house forecast. It’s based mainly on dynamical forecast models from the Copernicus Climate Change Service (CS3), but it also includes the Bjerknes Centre’s own Norwegian Climate Prediction Model (NorCPM).

Without further ado, here are our predicted temperature anomalies for June:

fc_t2m_6

It requires a bit of explaining. The colours indicate deviations from the normal temperature, which means the average over the past 20-30 years, depending on the model. The first five panels show the predictions from the individual models, the sixth panel shows (more or less) the average of these, and the bottom panel is our own combination of the model forecasts (Multimodel+). For more details on how we do this, please go to our Methodology page.

In short, the forecast is that it will be ever so slightly warmer than normal, but no large anomalies are forecast. The reason for the not-so-exciting forecast is that the models disagree. For instance, the ECMWF model predicts a warm June, while the UK Met Office predicts a cold June.

A pertinent question is: how skilful are these models? To answer this, we have prepared so-called skill maps. Here’s the one for June:

skill_maps_6new

The short story here is that blue means high skill, whereas red means low skill. Deep blue means a 20% improvement on ‘climatology’ (details). The maps are based on the models’ re-forecast skill. Our Multimodel+ forecast is moderately skilful in June in coastal regions.