,268 MONTHLY WEATHER REVIEW JULY. 19M) THE WEATHER AND CIRCULATION OF JULY 1958' Heavy Precipitation Associated With a Trough in Central United States

• Main Author: Carlos R. Dunn
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Pacific; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.394.8080; http://docs.lib.noaa.gov/rescue/mwr/086/mwr-086-07-0268.pdf

The outstanding feature of the monthly mean circulation pattern at 700 mb. for July 1958 was the large-amplitude wave which extended from the central Pacific to central North America (fig. 1). The circulation in the remainder of the Northern Hemisphere was characterized by blocking over the North Atlantic, with the westerlies strong and displaced well to the south. Over Eurasia a weak flow of rather chaotic nature existed with many truncated troughs and ridges. Another striking characteristic of this July's circulation was the large percentage of troughs and ridges which were located in climatologically infrequent positions. Klein and Winston [2] have showed that 30-day mean troughs and ridges have climatologically preferred regions of occurrence (fig. 2). A prominent aspect of their statistics is