SOME FEATURES OF THE CIRCULATION AT THE 10-MB. SURFACE JULY 1958 THROUGH JUNE 1959

Abstract

A recently published set of 10-mb. charts, analyzed six times monthly, is used as a basis for the discussion of circulation and temperature patterns during the year from July 1958 through June 1959. Comparison with events that transpired at that level throughout the previous year is made, and the most pronounced differences are investigated. The transition of the extremely stable summertime easterlies to the more intense wintertime circulation of predominantly westerlies is found to be orderly and closely related to radiation cooling in northern latitudes. In contrast, the timing of the highly complex springtime reversal can vary considerably from year to year, appearing to be influenced by the timing of wintertime developments such as ?explosive warmings? and accompanying circulation changes. During the winter of 1959, data coverage over the Caribbean area was sufficient to allow delineation of low-latitude disturbances. A 10-mb. shear line system, moving northward through the area during January, is briefly discussed.