I don't know of any confirmed UK sightings for July 19-20 or 20-21. However, a 'very weak' display was observed from Germany on 19-20 (full details still to arrive). Has been fairly quiet lately and the weather here in Scotland has been dire for most of the month...
AZI from Rostock, Northern Germany was ~ 003° - 020°, good visibility, better visible before on IAP Ruegen NLC Camera Network.
The night 2010-07-20/21 - I am sure - there was a display seen on the IAP Kühlungsborn Camera (0041 + 0053 UTC). Weak diagonal structures low above horizon - no gaps in the haze. This camera is only approx. 20 km west of my position. My own images are not a real proof because in this low area details sunk in the twilight very soon (first try to get an image was at 0101 UTC).
Best regards, Olaf
My observations of Aurora Borealis, NLC + PSC, additional hyperlinks to weather satellite images: 3sky.de