Looking at the current weather / atmospheric pressure readings today (Click on BBC link above) would suggest that this interference is caused by the current High Atmospheric Pressure which is centred over Europe. Also, current weather forecasts and predictions indicate that this High Pressure could last until this coming Sunday, at least.
While this current spell of cold but settled weather persists there is one very important thing to remember, if, at at any time, now or in the future you ever experience pixelation / breakup or a sudden loss of TV channels.....
Re-tuning a TV during periods of poor reception or loss of picture will usually only delete the TVs memory of frequencies / channels which were originally saved from the transmitter that your TV Aerial is pointing at, creating a bigger problem, often meaning you will be without TV pictures for much, much longer than people who didn't re-tune their TV.
With the exception of an on screen message suggesting a re-tune is necessary (For an example see my news item below, dated 22 August) or advise from someone like myself or TV retail shop etc, a willy-nilly re-tune of a TV in the hope that it will restore the channels should be avoided and is almost always counter productive.
The on-screen message "Weak or no signal" which sometimes appears on a TV screen while experiencing poor reception is NOT an invitation to re-tune the TV!