The amplitude and placement of the eastern CONUS trough next week on the 00z Euro tonight has trended wholesale toward the GFS solution, especially in comparison to runs from earlier on Wednesday and on Tuesday. Despite still being way east of the GFS and still going into Florida, the 00z Euro has shifted left, with a landfall in the Big Bend of Florida instead of south of Tampa. Looking closely, it seems the differences between the GFS and Euro happen in the first 72-96 hrs. The CONUS pattern mid next week is now almost identical between the two. That tells me that a lot of the final outcome for this system will be determined by now and Saturday/Sunday. The wave skirting South America today, with all the convection being restricted to the southern downshear side because of the northerly wind shear from Fiona, and the overall tendency for disorganized systems to move more left/west in general (because of the low-level trades in the Caribbean and the Coriolis force) would lead me to believe that there is a chance the GFS may be onto the right idea unless there is significant organization within the next 36-48 hours. GFS tended to lead the way with Fiona's more right/easterly track early on compared to the Euro. GFS, despite having a high false alarm rate for genesis of systems in the extended range, has pretty much led the way for the last few seasons in terms of track compared to other models (including the Euro and even the GFS ensembles) once it was working with a system that would develop. There was a statistical report put out about it earlier this year, in fact. Many more 00z GFS ensembles headed left toward the operational idea tonight. The NHC concensus model (TVCN) 06z run, based off the 00z globals, has shifted left and at 168 hrs is south of the MS coast and is pointed NNW, 00z ICON shifted solidly toward the GFS tonight. 18z Euro ensembles had also shifted left today, and the 00z UKMET shifted left tonight. I don't necessarily think the 00z GFS is right with a track into Louisiana (at least yet), but I do think a left lean but within the eastern 1/2 of the Gulf is probably a better idea versus a sharp northeast hook early on.
I'd feel much more confident in a sharper northeast hook earlier on if there was a trough axis west of the system as it comes up. That is not the case. This is just a system turning into a remnant weakness left over behind a departing trough (with upper-level heights actually rising with time in said weakness). That would still allow the northward turn for sure, but those situations usually have a more gradual rightward bend instead of something sharp and fast. Those are also cases where the ridging that fills back into the weakness sometimes trends stronger as we get closer, and it's sometimes a situation where a stronger hurricane can sometimes enhance that from "ridge pumping" with its outflow and subsidence on the outer northern side of the circulation. Climatology supports a right hook and fast northeast turn early on, but that climatology is also driven by those cases happening with troughs that dig down into the western/northern Gulf to grab those systems. This very much isn't that. We'll see what happens...