UDC 551.500.1:551.513.1(73)“1972.11” WEATHER AND CIRCULATION OF NOVEMBER 1972 Another Cold, Wet Month

• Main Author: Robert R. Dickson-national
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1972
• Subjects: Arctic; Canada; North Pole; Pacific; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.1192; http://docs.lib.noaa.gov/rescue/mwr/101/mwr-101-02-0182.pdf

at middle and low latitudes, and amplified ridges were observed near the North Pole and over Alaska (figs. 1, 2). The magnitude of the height anomaly in both the Arctic ridge and the central United States trough was unusual, approximating three standard deviations. This pattern evolved (fig 3) from October’s deep, highlatitude Lows and fast polar westerlies (Taubensee 1973). The midlatitude Pacific westerlies, which had been weak in October, were greatly energized during November (fig. 4) as cold air WRS driven to the Asiatic coast, sharpening thermal gradients and increasing the supply of available potential energy. Wind speeds were more than 5 m/s stronger than normal from the coast of China to the mid-Pacific. As the Pacific westerlies increased, circulation features from the east Pacific to the central Atlantic moved eastward. Mean troughs were observed in the mid-United States and off the east coast with a mean ridge over western Canada and Alaska. The midtropospheric westerlies over the United States were strong and displaced well south of normal; they were associated with a similar displacement of the storm track. 182 / Vol. 101, No. 2 / Monthly*Weather Review FIGURE 1.-Mean 700-mb contours in dekameters (dam) for November 1972. FIGURE 2.-DeParture from normal of mean 700-mb height in FIGURE 4.-Mean 700-mb geostrophic wind speed (m/s) for Novemmeters (m) for November 1972. ber 1972. Solid arrows show the observed axes of maximum wind speed, and dashed lines show the normal. FIGURE 5.--Departwe from normal of average surface temperature