I was thinking along similar lines but there are some conditions lacking to
confirm it is. With a nocturnal LLJ, unlike one induced by a mid-latitude
cyclone, the cooling aloft (900-850hPa) can only occur through land at a
higher elevation. For example, the Great Plains is often used in examples
from papers I have read. However, is it possible that the urban heat from
London could have triggered an effect, such that there was a thermal
gradient between Bedford and London even to that height ?

But 30 Kt ?
http://weather.ou.edu/~oscarvdv/maps...hetae_eur6.png
shws a surface convergence zone fed by Slies/SElies, presumably a heat low which wld make a
gradient.
Sdgs for Watnall and Herstmonceux 0Z have strong inversions but no low level jet.

And another, Blackardar (1957), Boundary Layer Wind Maxima and Their
Significance for the Growth of Nocturnal Inversions,
http://twister.caps.ou.edu/MM2004/Bl...ar1957BAMS.pdf (14.3MB)

Have you read the latter ?Joe
Now,I like 'obscure' papers ,but that one has evaded me!
;-)

--
regards,
david
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