Have found a Met Office pdf showing a map of Cornwall with average days of lying snow for the period 1971-2000. It look like at least 50% of the county has 3 days or less. Interestingly, one of the snowiest parts is the Lands End Peninsula with up to 10 days over the high ground to the west of Penzance.

http://www.metoffice.gov.uk/media/pd...st_England.pdf


Dick Lovett

Sorry, those maps gaive a great impression of detail & accuracy, shame they are totally wrong. I suspect they are some sort of projection based on altitude and reports from up the County (Camborne etc.)

I can see the tops of the moors from just behind Penzance, and the only winter in the last 20 years where there has been 5 days with snow cover, even on the highest tors, was 2010 with 12 (give or take 1) Several recent winters have seen no days with snow cover, even at the highest levels.

In Penzance, since 1992,
2010 had 9 days snow cover
next comes 2009 with 2 days
All the others have 1 (4 years) or 0 (15 years!)

I've also kept note of snow cover both on the Penwith Moors, and the Lizard, visible across the bay.

The Penwith moors have surprisingly little snow. Whilst the notable snowfalls are easterly blizards (now a long time since the last 1 in '87) almost all the snow here comes from a northerly. The 'snow' normally actually falls as rain & sleet (if you see what I mean!) until it crosses the tops of the moors, the highest points are only 1 mile from the north coast and about 200m or so. The snowiest parts are just above places like Madron, a couple of miles behind Penzance on the SE facing slopes.

From my observations I would give the average snow cover days per annum on the snowiest parts of the Penwith moors to be around 2 days (3 days at an absolute push - but I seriously doubt that).

The Lizard plateau is significantly snowier. The average on the snowiest parts could well be around 5 days (MCC Stithians?) I have noted many days in a showery northerly when the Lizard peninsula is almost entirely snow covered, when the showers are falling as rain/sleet/hail even at the highest levels behind Penzance. The Helston to Redruth area being the snowiest. I've had discussions with Martin R. about this. I think there are 2 main factors

1. Distance from the onshore north coast in a snowy northerly.
2. The Land's End peninsula is virtually an island, and turbulence created in the northerly airstream caused by it seems to mix in warmer air from the sea surface. In a northerly Penzance is often warmer than Scilly. (Not so in an easterly!)

Sorry it's all a bit long, but these accurate looking but inaccurate maps irritate me. I still recall the time when Scilly double recorded rainfall for 10 months, and despite me reporting it (and the fault acknowledged to me through the 'back door' - together with an account of why) the monthly rainfall anomaly maps for the western half of Cornwall were something to behold.. THe computer obviously having problems in reconciling the conflicting Camborne & Scilly data! Poor old Penzance in the middle was shown having rainfall wildy out.

Graham
Penzance