@deliacm
The trajectory of tropical storms or hurricanes predicted by ECMWF model is quite good. I observed it frequently.
But this model, like the other global models, is not so good at predicting the maximum wind speed near the eye of hurricanes. In any case it is better to rely on NHC advisories.
As you foresee long passage of several weeks, do you get broadband internet connection at sea, or do you stop every 2 or 3 days by calling at ports or mooring areas ?