There's an Open Skies inspection flight being conducted tomorrow by a Russian Air Force Antonov AN30.
Route will be from Chester heading north up the coast to Whitehaven then turn east to Scarborough via Harrogate (wonder why
)
It will then route South West back over the Pennines to Crewe and head back to Brize Norton. These flights are usually at about 4-5,000ft so it should be possible to get a decent blimp at it if you're anywhere along the way.
https://en.wikipedia.org/wiki/Treaty_on_Open_Skies
...forgot to mention. Due over Chester at about 10:50, Scarborough at Midday and Crewe at 12:30