The hurricane tracks are a new addition to Flowx but I believe it can be improved a lot. For example, you can color the dots by the hurricane category or wind speed. Better still, draw a heat map around each dot would generate a probability map for the hurricane.
The tracks come from one original simulation. If you look at the start of the tracks closely, you'll see the eye of the hurricanes diverge in a regular grid, so I'm guessing they are perturbing the direction and speed of the bulk movement of mass - I would have to research more.
So the initial conditions and early stages of the simulations are correlated, but each simulation is solved independently. The question is how long into the future can you consider each track less-correlated.
Given the met organizations release probability envelopes based on these track means it's a reasonable approach.
What I really want to do is weight the predicted wind speed with the probability map. I don't know if this will work. But you can imagine if a hurricane has a 75% change of going well into the continent it would weaken and cause less damage, but if the other 25% of the tracks go over sea and hit an island, it'll likely strengthen and cause more damage.
In any case, all the above will be interesting.