Besides individual model runs, there are two other types of model-based maps you might see on the internet. They’re both “spaghetti plots,” which depict many forecast tracks. In general, these provide a better sense of the potential path of a storm than a single model does.

One type of spaghetti plot shows the forecast path of several computer models, like the Euro and G.F.S., and several other hurricane-specific or global forecasting models. There are typically around five to 10 models on a plot like this. While you might think that these capture the full range of uncertainty, they often do not. They’re even more prone to understate the total uncertainty than the National Hurricane Center “cone.”

Another type of spaghetti plot shows an ensemble forecast. Unlike a typical “determinist” forecast, which takes current conditions and simulates a single scenario forward, an ensemble model varies initial conditions slightly and then simulates, propagating uncertainty through the forecast. The European ensemble includes 50 different ensemble forecasts, called “members,” each beginning with somewhat different initial conditions. The G.F.S. has 30. The calibrated Euro ensemble comes much closer to representing the full range of uncertainty than the “deterministic” runs of a few different models.

The National Hurricane Center forecast track is typically based on all of these models. The forecasters use their judgment in deciding how much weight to give to certain models, or how quickly to react to changes in the models, but the official forecast rarely deviates very much from the model consensus.

Right now, the major models are as close to a consensus as they’ve come. Both the G.F.S. and the Euro place Irma right next to Miami on Sunday, heading north up the Florida coast toward South Carolina or Georgia. That’s exactly where the National Hurricane Center forecast track goes.

But the ensembles, which are fairly tightly clustered, betray the greater uncertainty. Irma is forecast to make a sharp right turn to the north somewhere near Florida. But since the Florida peninsula itself runs north to south, the exact timing of the turn takes on a lot more importance. A 50-mile difference in when Irma turns north might not be much from a meteorological perspective, but it could make the difference between a direct landfall on Miami or Charleston, S.C. — nearly 500 miles apart. The same problem emerges if the storm heads farther west. Then suddenly the Gulf Coast could be at risk. You can see the ensemble forecasts for yourself here, but in general the official cone of uncertainty is still the best way to consider the range of possibilities at a glance.