The only thing that's certain is the current 240 hour forecast will has a less than 5% chance of actually verifying, there are large players to be determined. Just look at a forecast trend of the last 4 runs of the 00z ECMWF @ 144 hrs (not even going to touch a 240 hour forecast trend, too much variation):
The models have consistently overdone troughing this season, and we only have to go back 3 weeks to Barry to see this (early forecast was for a FL panhandle landfall, but ultimately this ended up going much further west):
For this particular system, there are quite a few atmospheric influences we need to pay attention to. I hate to use a 240 hr forecast, but using the current ECMWF, the 3 main things to focus on:
1) Ridging extending over the CATL into the Caribbean will have a major influence. Not only can a stronger high pressure to the north accelerate the forward speed of the wave, it could also keep it on a further southerly track. When/where the main vorticity is established along the wave axis also plays a role here.
2) Large trough extended over the Northern Atlantic. The position, tilt, and strength can both amplify subtropical ridging above this wave (a further west track), or further erode the western periphery and allow for a quicker recurve.
3) Shortwave trough over the East Coast/NE U.S., again the strength, timing, placement, and orientation play a massive role here in steering. If this is displaced further NE, it could have little influence and allow for this wave to go much further west. An orientation more NE to SW could even allow for a recurve very near the EC (or possible landfall).
Bottom line, there's a lot of players that determine steering (not including downstream implications mets have been discussing this morning), and a -NAO doesn't guarantee a recurve, it just slightly enhances the chances.
I on the other hand if anything, I think that both the Euro and UKMET have over done on ridging across the eastern US in their 96-168 hr forecast.
