ronjon wrote:
Actually KWT, the pattern depicted by the models doesn't look progressive at all - its blocked up with the trough and huge low getting stuck off the mid-atlantic coast for literally 5-7 days!
The upper level is still rather progressive though I agree its getting slower with time and the pattern does become a little slack towards the start of September.
Aric, yeah I agree with all you say there is of course things that could throw a spanner in the works but even a weak sheared system will likely recurve...take a look at Colin the models forecast the trough to be of similar strength, that still recurved and it barely was a TC at times, a strong hurricane which this very likely will be by day 6-7 will recurve I'm pretty sure.
As for the GFS, I rememer it trying to do the same trick with Bill...the ECM got it bang on that time with the troughing and this time round the ECM hasn't once shifted from the east coast trough in the last 5 days...when you've got 10 runs all showing more or less the same broad evolution (granted there are differences in exact placement) it really brings big confidence, esp when its doing the same thing with both a weak and a strong system and all models do the same thing...its not like we even have one model that is showing anything other then the odd run here and there that does anything different.
best we can do is current analysis after that its all hopefully an educated guess lol the error actually starts with the current analysis by anyone, so its best to only go 48 hours out at the most especially with just an area of disturbed weather. A series of short term forecast add up to a long term forecast 