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The plots below show the tropical cyclone activity for 31 August to 1 September. Already in the earliest forecast (from 24 August) the probability for a tropical cyclone in the northern part of Gulf of Mexico was above 20% and in the forecast from 25 the probability increased to above 50%. However, in the subsequent forecasts the probability decreased again. This change was connected to the whether the cyclone should form already in the Atlantic, which it did not. But later Hermine formed in the same tropical depression.
The intensification of Hermine that was in early forecast once it starts moving over the open sea did not materialize. When Hermine made landfall on Friday, 2 September, it lost a lot of its intensity and more or less it's kept it later when it moved again over the ocean whilst some early forecasts suggested intensification especially the HRES. The good point is that the reported core pressure falls within the ENS range although at the upper tale of ENS distribution. It's also worth mentioning that the ensemble spread was quite large and the HRES was also within the range of the ensemble but at the lower tail. Regarding the track, Hermine moved north-eastwards at some point it changed the direction approaching the north-east US coast. That turn in thr direction was given by a number of ensemble members as well.
Verification of Hermine's track forecast based on 2 September 00UTC run. Red dots represent the reported core pressure of Hermine.
3.4 Monthly forecasts
3.5 Comparison with other centres
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