Plumes - the very best of British summer weather imo! Plenty of warm or hot weather, warm nights (yes I do love those!), abundant sunshine (albeit hazy sometimes) and good chance of thunderstorms too. Hope to see plenty of them May-September this year as they've been fairly lacking in recent years from what I remember.
The 850 charts show them up well like this one from August 2003:
http://www.wetterzentrale.de/archive/ra/2003/Rrea00220030806.gif
Just looking at it makes me feel warm