Monthly and annual totals of RAINFALL 1971 for the United Kingdom .^~~ I B lit DATA UKMO Duplicate National Meteorological Library FitzRoy Road, Exeter, Devon. EX1 3PB Distribution; Recipients of the 1971 volume Monthly & Annual Totals of Rainfall for years 1969 and 1970 Addendum regarding the 1916-50 Average Annual Rainfall We regret that due to a mistake in the computer program which extracted the data for the main tables of data, all 'estimated averages 1 were in fact printed as well as worked and weighted averages. Thus, each station appears with an average annual rainfall and in some cases the estimated average published has proved to be unrepresentative for the station concerned. Monthly & Annual Totals of Rainfall for the year 1971 Note regarding the Average Annual Rainfall entries May we draw attention to paragraph 6 of the Introduction to the 1971 volume (being despatched herewith). The Average Annual Rainfall values being published in this volume relate to the new reference period, 1941-70. IletOS Braclcnell Met Office National Meteorological Library & Archive FitzRoy Road, Exeter, Devon, EX1 3PB Tel:+44(0)1392 88 4838 Fax: 5681 email: [email protected] www.metoffice.gov.uk Front cover photograph; A rainy evening in Richmond, Surrey by permission of Mr K. E. Woodley DUPLICATE WETEOhOLOG/CAL Met Office r National Meteorological Library & Archive ive Lor FitzRoy Road, Exeter, Devon, EX1 3PB Z UK Tel:+44(0)1392 88 4838 Fax: 5681 email: [email protected] www.metoffice.gov.uk This publication must be returned or renewed by the last date shown below. Renewal depends on reservations. Extended loans must be authorised by the Librarian. Publications must NOT be passed to other readers 21 AUG 2003 3 8078 0002 3831 3 (c) Crown copyright 1980 Published by the Meteorological Office London Road, Bracknell, Berkshire RG12 2SZ UDC 551.506.1(41-4) ISBN 086180 026 5 11 INTRODUCTION This publication 1. The present publication is the third in the new paper-back series which provides the information on rainfall over the United Kingdom that was formerly given in Part I of British Rainfall. It gives monthly and annual totals of rainfall and, where available, the rainfall on the wettest day of the year by amount and date(s). Station details 2. The publication includes the 'Hydrometric Station Number' for each station: this is the reference number used by the Meteorological Office to identify station data. 3. The county in which the rain-gauge site is located is given by a 'County Number'. A decode of the county numbers is given on page xi. (The counties in use in this volume are those in use in 1971, that is prior to the 1974/75 Local Government reorganization.) 4. The location of the rain-gauge site is given by National Grid Reference to the nearest 100 metres, and the altitude of the rain-gauge site above mean sea level is given to the nearest metre. 5. The name of the rainfall station is that used by the Meteorological Office under rules which require that the primary name should normally appear on the 1-inch Ordnance Survey map and/or its 1:50000 metric successor; the supplementary part of the name, which appears after a comma, is included to assist identification, e.g. 'York, Poppleton' and 'York, Acomb Landing'. For stations whose data were published in British Rainfall it is obviously desirable that there should be some continuity in naming; in a few cases this consideration has been given preference over the usual naming rules and the name adopted may not in fact appear on current Ordnance Survey maps. * Where a station name is prefixed by an asterisk, the rain-gauge is set with its rim at ground level, surrounded by a pattern of antisplash grid which is accept­ able to the Meteorological Office. #Where a station name is prefixed by a hatch symbol, the station is located in England although it is shown within the Hydrometric Areas associated with Scottish River Purification Boards; such stations fall within the data areas of the Northumbrian River Authority if in the north-east, or of the Cumberland River Authority if in the north-west. >Where a station name is prefixed by a 'greater than' sign, the data originated from a rain-gauge of a tipping-bucket type which provides data acceptable to Meteorological Office standards for data archiving purposes. 6. The average annual rainfall at stations for the latest reference period, 1941 70, is given in as many cases as possible. Estimated averages are not included. The ability to include values for this latest reference period arises solely from the delay in publica­ tion of the 1971 data; it is not usually possible to introduce new averages until a few years after the end of the reference period. Thus, values of percentage of annual average now printed will be somewhat different from those published for selected stations at an earlier date (e.g. the Monthly Weather Report for 1971), for which the averages relating to the 1916 50 period were in operational use. Representative figures (Table B) for the monthly and annual rainfall of 1971 in England, Wales, Scotland, Northern Ireland and the Isle of Man are given as percentages of the longer-period averages (1941-70) in Tables C and D. 7. River flow measurement stations, although in some cases allocated a 'Hydrometric Station Number', are not included in the publication. Rivers and streams 8. The publication follows earlier practice in that it endeavours to associate rain- gauges with particular catchments and accordingly names the associated rivers and streams. 9. It is not practicable to identify every stream in the country and some minor features have necessarily been ignored. However, in general, a stream is separately identified if it is more than four miles long and has, or has had, a number of rainfall stations within its catchment. 10. As with station names, a number of subjective decisions have had to betaken. The name of the river or stream not uncommonly changes throughout its course: a stream which enters and leaves a lake may thereby acquire a new name. In general, such rivers are identified by the name in use at the lowest reaches, that at the mouth or that at the confluence with a larger river to which it is a tributary. River authorities and hydrometric areas 11. Although changes in local government boundaries and changes in water authority organization took place in 1974/75 and this booklet is published after that time, the data are related to arrangements in existence at the time of the observations and to the river authority areas (in Scotland to River Purification Board areas) in 1971. Data 12. The unit of rainfall amount that is used is the millimetre (mm). Monthly and annual totals are the summation of daily and monthly totals in that unit. If for any station or any period the unit of measurement was the inch, the daily data have been converted to millimetres; the monthly totals now reported for such stations are the sums of the daily millimetric equivalents of the rainfall measured. 13. The data from each station have been subjected to the routine quality-control procedure in operation by the Meteorological Office at the time of data receipt. Any corrections or adjustments have been incorporated in the figures now presented. 14. Certain practices operating during the period of publication of British Rainfall have been kept, namely the retention in archives of all data as originally submitted, and the omission from the published information of data from stations which appear too unrepresentative of the rainfall regime indicated by the bulk of rainfall stations in the area. 15. The present publication continues the practice commenced with the first new paper-back edition, that for 1969, in that reports from stations from which data for the year are incomplete are included. Some stations opened or closed during the year and for others a local shift of site occurred which is thought to have been sufficient to raise doubts about the homogeneity of the old and new observations. New hydrometric station numbers have been allocated in the latter instance. 16. When data are missing in a random manner from the Meteorological Office data set for 1971, then the station in question will not, in general, be included in the lists of published data. In a certain limited number of cases, missing monthly totals are estimated and such estimated values are shown in the table by brackets around the totals. Where totals have been subject to substantial amendment during the quality- control process, this too is indicated by the presence of brackets around the rainfall IV totals. Such amendments, in addition to the treatment accorded to suspect daily values, could arise for example from the reapportionment of rainfall reported when the observa­ tion on the first day of the month has been missed, or because of adjustments arising from snowfall. 17. The maximum amount of rainfall in a rainfall-day is given in the last column together with the date of its occurrence. Should the amount be equalled on other dates within the year, those other dates are included, subject to a maximum of three date entries, shown in date order. For stations which commenced or terminated within the year (i.e. with some months' entries shown as dashes) the maximum daily amount is shown related to the period of available data. The maximum daily fall is not shown for stations whose data were received only as monthly totals or for which, for one reason or another, daily data are incomplete for the relevant period of record within the year.