My AWS figure was corrected for the snowy spell using totals from my snowdon - bringing the funnel inside every morning at 9am and letting the snow melt in to the bottle before measuring - a real painstaking experience. The total for the snow that fell on Sunday 20th was 9mm - consistent with the depth of 9cm (using the 1mm=1cm rule). it's fairly consistent with other totals close by - so I'm reasonably confident on accuracy