Atlantic Weather Charts

Abstract

THE Meteorological Council has just issued a folio of synchronous weather charts for the North Atlantic Ocean and the adjacent continents, those now published forming the first part of a series which embraces the thirteen months from August 1, 1882, to August 31, 1883. The whole series is to be issued in four parts, Part 1 containing the charts from August 1, 1882, to November 7, 1882. Two charts are given for each day—one shows the barometer, wind, and weather, whilst the other gives the air- and sea-temperature, and weather, the weather being given on both charts for the purpose of easy comparison with other elements. The isobars, or lines of equal barometric pressure, are drawn for each tenth of an inch, and figures are given in the central areas of the several depressions to show the lowest reading of the barometer recorded by vessels passing through these disturbances. The direction and force of wind are shown by a system of arrows which fly with the wind, and the different forms of arrow exhibit very readily where the wind reaches the force of a gale, whilst the winds at high-level stations, where the elevation is 4000 feet or upwards, are indicated by red arrows. The air- and sea-temperatures are shown by different coloured isotherms, or lines of equal temperature, which are drawn for each 5° F. The weather, such as rain, fog, or mist, is shown by different methods of shading, and, as mentioned above, is given with each style of chart. The synchronous hour for which the observations are charted is noon Greenwich time, except in the case of air- and sea-temperature, where local noon has been taken in preference. No letterpress has been published with the charts except a few explanatory notes, in which it is stated that the study of the weather of Western Europe for many years has established in a manner that is beyond question that the atmospheric disturbances, on which the changes of weather are in a great measure, if not mainly, dependent, reach our western coasts after having passed for a longer or shorter distance over the Atlantic. The Meteorological Council undertook the investigation with a view to ascertaining as far as possible the conditions under which such disturbances either originate in or traverse the Atlantic, and the extent to which the direction of their course, their magnitude, and persistence, may be influenced by the general meteorological conditions of the area within which they are generated, or of the regions which surround that area.