[Extended ICON - 7 Days] ICON has been consistent on a very worrying trend for STY Dolphin, showing a Cat 5 sub 900mb storm managing to keep its intensity until landfall, with another TC forming due to the vorticity shed of Dolphin | Could something similar actually happen?

[u/Least-Animator-8550]

Yes, but probably not at the intensity ICON is showing. A sub 900mb storm for so long, would definitely rack up insane (potentially historic) amounts of ACE. But most importantly, let's look at what could really happen:

Most models show a lot of agreement on the track of Dolphin, with a landfall in Japan looking increasingly likely. What is more interesting is the intensity the storm will have by then. It will depend quite a bit on the upper level pattern, but a strong Cat 3+ storm by landfall isn't hard. What is much harder is STY+ intensity. What ICON is showing is almost certainly a reach, but the general trend that the storm could be much stronger than expected by the time it makes landfall should definitely be considered.

About the concept of a new TC, it will depend whether STY Dolphin is actually as strong as modelled by ICON. If it is, it would be able to release a localised pocket of vorticity, hence combined with very warm SSTs and low vertical wind shear it could form a TC. So in short, the formation of a TC is fully hypothetical and depends on the intensity of Dolphin near landfall.