I am looking for a reason to explain the difference in interpretation between the professionals and some of the leading lights on the forum.So these show extremely limited convection with a low level inversion and very dry air above. If these forecast tephis turn out to be correct there will be nothing but v light showers as JH for one, has also been pointing out for some time. Some of the other posters say that with a wind in this direction and with forecast wind speed and the forecast uppers they will be astonished if there is not significant snowfall in the south east. Some of these seem to be implying convection potency from the upper temp charts. Now I am sure that with identical pressure charts in the past there has been significant snow fall, but I am equally sure there are occasions that have been dry. The difference might be explained by the upper air profiles. If the 850s are very low but the 1000-500 thickness is just so-so then surely the 1000-850 thickness is not going to be that special; the really cold air is shallow. On the other hand if 850s were -6 and the 1000-500 thickness was slightly lower, the depth of the cold air would clearly be much greater.The former case is very cold dry weather as forecast; the latter is possibly one of those "i remember when 850s were only -5 and we had a foot of snow from showers/streamers etc occasions that some of us fondly remember"
To try and demonstrate the case it would be grate if someone could dig up a tephi ascent from one of those recent heavy easterly snowfall events, like the surrey/south eas t event of late november 2009 or 2010.
I've of course no idea whether the forecast tephigrams are correct or could be subject to change but must admit I'm intrigued by the concept of launching a balloon 4 days into the future and sending the results back to present!
regards to all