Influence and Prediction Value of Winter U.S. East Coast Trough for Spring Cold Front Frequency Over the Middle and Lower Reaches of the Yangtze River

Abstract Cold fronts are an important meteorological system over East Asia, which generally lead to cold waves, extreme precipitation, and other weather phenomena. The climatology and variability of spring cold front frequency show the highest center in the mid‐low reaches of the Yangtze River (MLRYR), based on the objective identification method. The spring cold front frequency over the MLRYR is strongly associated with the variation in U.S. east coast trough axis during preceding winters. During the winters with eastward‐shifted U.S. east coast trough axis, the positive (negative) geopotential height anomalies are detected over the high‐latitudes and tropics (mid‐latitudes) in North America and the North Atlantic. Such atmospheric circulations can induce tripole SST anomalies in the North Atlantic via altering surface heat fluxes. The tripole SST anomalies persist well from the preceding winter to spring and induce a meridional tripole circulation mode over the North Atlantic, further triggering a wave train which propagates downstream and induces negative geopotential height anomalies over Northeast China, intensifying the East Asia trough. The enhanced East Asia trough favors more southward cold and dry flow, consequently enhancing the equivalent potential temperature gradient over the MLRYR. Such atmospheric changes correspond to more cold front activities over the MLRYR. Leave‐one‐out cross‐validation shows that the preceding winter U.S. east coast trough axis might act as a potential predictor for the spring cold front frequency over the MLRYR.