stormchazer wrote:Kerry04 wrote:So now we have 4 models going west? (GFS,UKMET,NOGAPS,NAM)
In the longer range, they all seem to show another turn to the NW or N after that W motion-- reflecting the influence of the next trough. They do show a western component but then, recurvature.
Yes, there is no doubt recurvature will take place - the key is what longitude? I think what's really interesting here is that the weather pattern at the upper levels is evolving as we speak. Yesterday, after trending west during the previous two days, the GFS was the first global model to predict that high pressure would fill in and block an early recurvature ala GFDL. Today, we have the NOGAPS, UKMET, and NAM joining the GFS. With the highly respected GFDL and the Euro still predicting an early recurvature we still need to drop back 10 and punt on its future track. However, if the mighty GFDL follows suit tomorrow, then we'll have some certainty that Helene will probably make it west of Bermuda - how far west is another entirely separate question because assuming the GFS scenario pans out, and by no means a done deal, we need to gaze into the crystal ball of the upper air pattern in 7+ days. Will the high pressure building and blocking Helene's northward recurve remain stationary or move off in a progressive fashion. Climatology would say its mid-late September and its gonna be progressive. On the other hand, a highly amplified deep western US trough that reloads would tend to build the eastern US ridge and be much less progressive - I'm going to be focusing on that SW-Central Plains trough this upcoming week - the Euro already holds back the trough while the GFS is more progressive with it moving it toward the Ohio Valley in 6 days - it appears that the 18Z GFS run has already backed off somewhat on the eastward movement and takes a piece of energy up thru the Great Lakes and NE around the northern portion of the east coast high pressure. The strength and persistance of the east coast high pressure in 5-7 days will determine if this storm will be an east coast threat - assuming that the GFDL early recurve solution is incorrect of course - still a big if.
I changed it.
