In spite of the remarkably snow-free season, snow cover on our mountains was reported somewhere in every month from September to May, and in October the snow line was down to below 2000 ft. at each of the representative stations from Sutherland to South Wales, in marked contrast to the 1947–48 season when no mountain snow cover was observed in this month. The duration of snow cover in March 1949 considerably exceeded that of March 1948 at all mountain stations. Snow cover was first reported from the Cuillins and the Cairngorms on September 22nd, with the snow line down to 2000 ft.
Diagrams showing the distribution of snow cover relative to height are given on pages 368 and 369, the basis for these graphs being as set out on p. 131 of the 1946–47 Report.Footnote *
At Elphin the duration of snow cover was longest at all levels in February, reaching 10 days at all altitudes, an unusual distribution relative to height due to the snowfalls being followed by heavy rains which rapidly cleared the snow at all levels. No snow was reported to be lying at any level in November, December, January or May.
At Glen Brittle in the Cuillins some snow cover was reported in every month from September to May, with a maximum of 23 days at and above 3000 ft. in January. In Glen Lyon the snow line was down to 2500 ft. in every month except May, the duration exceeding 20 days at 3000 ft. in March. In Glen Livet the snow line was down to 1000 ft. on some days in every month throughout the season, with a maximum duration of 19 days at 3000 ft. in March.
In the Lake District, at High Close, no snow cover was observed in November or May, and in no month did the duration reach 10 days at any level, the maximum being 8 days down to 2000 ft. in March.
On the Caernarvonshire mountains snow cover was observed from Capel Curig in each month of the season, though in November it was confined to but one day at 3000 ft. At this station the maximum duration was 11 days at 3500 ft. in January.
At Llanfrothen no snow lay at any level in October, November or May, and in December the duration was but one day at all levels. The maximum duration at all levels occurred in January, reaching 5 days at 2000 ft. No snow cover was reported at any level from Tairbull, Brecknockshire, in November, February or May, and in January the duration did not exceed one day. The duration in March was 9 days at 3000 ft. and 7 days at 2500 ft. In the remaining months the duration did not reach 5 days at any level.
Fig. 1
Data from six representative stations are summarized graphically in Fig. 1 above by curves showing the total duration of the snow cover throughout the season. Above the 500 ft. level the duration on the Cuillins, as observed from Glen Brittle, exceeded that at all the other stations, with a maximum of 89 days above 3000 ft. It is of interest to note that the duration of snow cover on this range exceeded that of the 1947–48 season at all levels.
At the remaining stations the duration at all levels above 500 ft. was considerably less than in the previous two seasons and at none of the stations in England or Wales did the duration of snow cover exceed 35 days at any level.
D. L. C.
