THIS WILL BE VISIBLE FROM THE UK (conditions permitting).
From 0628 to 0652 UT there will be a very rare triple shadow transit of Jupiter by Io, Europa and Callisto when Jupiter will be c20deg above the Western horizon. Shadow times are:
Callisto: 0311-0800
Io: 0435-0652
Europa: 0628-0922
There is some interesting reading on triple transits here: http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=2002JBAA..112..287M&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES
For info: you can find the times of all the transits and occults of Jupiter's moons in 2015 in the attachment (source skyandtelescope.com).
Event details