It's quite obvious to most that during the last fifteen years or so average
CET's have risen. It has just dawned on me however that the average CET is
probably lower than it would otherwise be, if and I emphasize *IF*, it was
correlated to the average 850MB temps for the past 15 years over the UK. It
seems to me that CET averages in the past decade have been kept artificailly
low due to the inversion phenomenon. For instance in 1998 during a period of
"Bartlett highism"
a frost occured over most of the UK even though 850MB temps were 5C+,
sometimes reaching as high as 13C. The question I have, is there any
scientific body that compares average 850MB temps for the past 30 years?



It seems to me that for the UK to experience snow, unstable air has to occur
in the form of low 850MB temps. eg -5C and below. Apart from the occasional
brief Artic blast, genarally speaking for the past decade 850MB temps have
been above the neccessary threshold. Most of our sustained "cold" periods
have been due to "warm high" inversions. It's a worrying trend, that keeps
nagging me!


Regards


Sean Blowman