What am I seeing?

[Hat Monster]

Looking to the east, I can see flashes in the sky behind the clouds, one perhaps every twenty seconds. Space.com's aurora display shows low activity. http://www.space.com/spacewatch/aurora_cam.html
The flashes are white, and brief, often coming in pairs but not always. No sounds heard, and it's pretty quiet here.

[Donnie B.]

Location? Time of day? Weather conditions?

A thunderstorm more than a few miles away will produce silent flashes of light. The sound doesn't propagate nearly as far as the light does, on a dark night.

[Christopher Ferro]

Sometimes distant strobe beacons on radio or cell towers can be seen from far off, especially if there are low clouds or fog. I've seen impressive flashes like that on the way to eastern NC.

[Hat Monster]

I've been thinking it's lightning, yes. It's a clear night except from the bit of cloud in the east.
I'm in central UK, it's dark and I was having a look at Jupiter when I noticed.
http://www.nottingham.ac.uk/meteosat/D2.JPG
Live image, you can see the cloud bank on the east of the UK. I'm to the west of that, but not by much.

[Pi Man]

... Or, it could be an actual UFO sighting!!!
You didn't get it on tape, did you? /phpBB/images/smiles/icon_eek.gif
(Joking /phpBB/images/smiles/icon_biggrin.gif)

[roidspop]

Maybe the RAF is playing?