During the past 4 years noteworthy weather fluctuations of a persistent kind have occurred over large portions of the United States, the most prominent of which have been the deficiency in precipitation over the Northeast and the excess over the Southwest and the Northern Plains. The nature of these abnormalities is described with the help of seasonal frequency distributions of precipitation determined for 40 climatologically homogeneous areas of the country. From this and other material it is shown that the Northeast drought has been largely a spring and summer phenomenon at the same time when abundant rains occurred over the Northern Plains and Far Southwest.The large-scale upper-air currents favoring or inhibiting precipitation through interactions with air masses and storms are next described. The most consistent year-to-year feature of these upper winds in the quadrennial has been the persistence of one southward dip in the westerlies just off the eastern seaboard and another over the Far Southwest.A hypothesis is proposed for the cause of the aberrant upper-wind currents which considers the atmosphere and ocean as a complex coupled system. Abnormalities of sea-surface temperature are created by anomalous gurface wind drag and by extraction of heat by anomalous air masses. The ocean thus serves as a reservoir whose heat transfer affects sequences of atmospheric systems. An attempt is made to show that a feedback system of this type has been operating efficiently during the past 4 years so as to produce the observed anomalous weather patterns.

No abstract

Temporal coherence between monthly mean temperature patterns for the sea surface of the North Pacific is far greater than any known meteorological coherence, has a smooth non‐Markovian die‐away with increasing lag, and is greatest when preceded by cold season months. When stratified according to initial month, the data show a striking tendency for pattern recurrence from one nonsummer month to subsequent months out to two years except for summer. Apparently this pattern recurrence is due to storage of anomalously cold or warm water that is shielded by a shallow layer in summer but is stirred up to the surface by the increased wind stress during cold months.

No abstract

No abstract

No abstract

No abstract

No abstract