Any type of northern Gulf of Mexico threat from Tropical Storm Ernesto has now come and gone. I mentioned as early as Thursday and Friday (Aug 2-3) that global guidance would likely win as far as forecast track. It appears that indeed was the case.
However, an interesting graphic developed over the weekend by NOAA Scientist Corey Pieper (@Geostrophic) reveals, in fact, the National Hurricane track guidance will go down as a complete success. Although the actual track of Ernesto hugged the southern region on the original “cone of uncertainty”, it never meandered out of that highlighted yellow region.
An average 5-day forecast from the National Hurricane Center can range over 230 nautical miles. So, while it may “seem” that Ernesto’s track was a whiff, indeed it turns out that possibly the tropical guidance was a whiff. The GFDL and the HWRF both had strong turns northwest into the Gulf of Mexico – a theory that never played out.
As we have said before, it never really has been a problem with forecasting WHERE tropical cyclones go, rather how STRONG they become. There are so many micro variables that have to go just right to get strengthening in a tropical cyclones. Those micro variables, right now, are nearly impossible to simulate in forecast models on that run on a regional or global scale. It is likely we will never see a model(s) that ever forecasts tropical cyclone strength with any skill in our lifetime.