Arrived in London for the Diamond Jubilee Weekend only to find horribly overcast and lightless light! Some mediocre photographs definitely required manipulations before uploading but, what a fantastic weekend, no weather could spoil the wonderful spectacle and atmosphere that was London this weekend.
I've found that a little HDR on three fused exposures can make an otherwise poorly lit image really pop. Your pic is just fine! Moody, and the clouds look great!