August 2, 2013, by Lucy

The National Snow Survey of Great Britain

Throughout the project we’ll be exploring some of the sources that can be used to explore past snow events in Britain. The subject of today’s post is the National Snow Survey of Great Britain.

At one of the first meetings of the Association for the Study of Snow and Ice held in October 1937, members noted that, “remarkably little information was available with regard to the frequency with which the higher uplands of Britain are covered with snow… Accordingly, the Association decided that a minor but useful part of its work was to try to fill this gap. A simple scheme was drawn up by which a number of observers in mountainous districts were to be asked to send in weekly a printed postcard on which a record was made each morning stating whether snow fell at the station and whether or not snow lay at the station or at 1,500, 2,000, 2,500 and 3,000 ft” (G. Manley, Observations of snow cover on British mountains, Quarterly Journal of the Royal Meteorological Society, Vol. 67, January 1941).

The papers of the Association indicate that the survey started with around 14 observers at the following stations:

(a)    Glendessary, Strathyre, Ben Lawers, Glenfeshire, Derry Lodge

(b)   Craigdarroch (Sanquhar), Eskdalemuir, West Linton, Soutra, Doddington

(c)    Glenridding, Garrigill, Stanhope

(d)   Crickhowell (Brecon)

We’re hoping that the observations from Garrigill and Crickhowell will be particularly useful for this project! In 1938-39 those 14 observers between them sent in 250 postcard records to the survey. Each postcard required the observer to note:

1)      Days on which snow or sleet fell at Station

2)      Days on which snow lying at 9am: at Station, at 1,500 feet, at 2,000 feet, at 2,500 feet, at 3,000 feet, at 3,500 feet

3)      Days on which snow drifts remain visible

4)      Average depth of snow around Station (inches)

Put a X for “yes”; and query ? for “Cannot see”; a nought O for “None”.

“Snow lying” means more than half of ground at this level covered with snow.

On the reverse there was space for ‘Remarks on character of storms at Station – day, wind direction, whether much drifting of blocked roads’.

The Association thus established a national survey of snowfalls and snow cover in Britain. Unfortunately “the year 1938 gave as a whole less snow than any other year in this century… so that it was difficult to maintain interest”  (G. Manley, Observations of snow cover on British mountains, Quarterly Journal of the Royal Meteorological Society, Vol. 67, January 1941). With the outbreak of War in 1939, the survey suffered further disruption and a temporary halt but post-war, in 1946, upon the Association changing its name to become the British Glaciological Society, the survey was resumed under the direction of Mr E.L. Hawke, then Honorary Secretary of the Royal Meteorological Society. In 1946, the Society announced its particular interest in recording the snow patches at high altitude which might remain year round. The 1946-47 report was based on the work of some 120 volunteer observers. Month by month summaries describe the weather conditions and are followed by diagrams of data for selected stations, the report capturing the extreme winter of 1947:

February 1947

Weather of excessive severity prevailed throughout the country.

There was no day throughout the month on which snow did not occur, even at low levels, in one or another part of Britain.

The records indicate that more than two-thirds and perhaps as much as three-quarters of the total area of England, Wales and Scotland lay continuously under snow from start to finish of the month.

Annual reports of the survey were published by the British Glaciological Society between 1946-47 and 1952-53. In 1953 the work of the Survey terminated, and the collection of the records was taken over by the Meteorological Office. The Meteorological Office published snow surveys for the period from 1953-54 to 1991-92.

The survey continued to draw on daily records compiled by a network of amateur observers, many of whom also submitted rainfall data to the Meteorological Office. Data were sent each month throughout the season from October to the following May, the main period of likely snowfall, although some observers submitted extra reports if snow occurred at other times of the year. The 1953-54 report explains:

“These records relate to a network of land stations distributed over the country, and are augmented by data extracted from the regular monthly returns from official weather stations and from voluntary climatological stations to the Meteorological Office. In addition, information on snowfall around our coasts has again been provided by the returns from lighthouses and lightships, made available by the courtesy of the Elder Brethren of Trinity House and by the Commissioners of Irish Lights, from and also by the returns of a number of ships at sea, supplied through the good offices of various shipping companies. Without the co-operation of all those responsible for these voluntary observations it would not have been possible to have prepared this report in anything approaching its present detail.”

If you’d like to read more, the Snow Surveys from 1953-54 to 1991-92 are available online from the Met Office website: http://www.metoffice.gov.uk/archive/snow-survey

To conclude, a quote from L.C.W. Bonacina (Fellow of the Royal Meteorological Society) who, in response to the publication of the 1946-47 National Snow Survey, wrote in a letter to the Journal of Glaciology, “Mr C.K.M. Douglas is quoted as saying that 1946-47 was undoubtedly the snowiest winter of which we have any precise record. This, however, is in itself a cautiously worded non-committal statement in so far as it does recognize the difficulty of making precise comparisons. It has to be remembered, too, that weather memories, even among meteorologists, are short, so that recent experiences tend to be over-estimated” (The National Snow Survey of Great Britain, Journal of Glaciology, 1948 part 4, 204, emphasis added).

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