..........the statement
made by the commentator that 'There has been reduction of blocking Highs
across the U.K. thereby allowing the JetStream a freer access to Western
Europe' . Is that true ?
this is consistent with with the tendency to +ve values of the NAO index in the latter half of the
C20,though in recent years this seems to declined .However,I'm not sure the conventional NAO indices
reflect properly current storm track regimes.It's hard to find an uptodate blocking climatology,most
concentrate on cyclones.(tho I haven't looked exhaustively)
This recent paper may be of interest-

Trigo,R.M., I. F. Trigo, C. C. DaCamara, and T. J. Osborn, 2004: Climate impact of the European
winter blocking episodes from the NCEP/NCAR Reanalyses. Clim. Dyn ., 23 (1), 17-28.
online at-
http://www.nersc.no/MACESIZ/Papers/tri04.pdf

Also it's discussion of cloudiness and max/min temperatures may be of relevance to the perceived
decline in fog mentioned elsewhere,

--
regards,
david
(add 17 to waghorne to reply)