The 1993 Superstorm Cold Surge: Frontal Structure, Gap Flow, and Tropical Impact

In the wake of the eastern United States cyclone of 12-14 March 1993, a cold surge, originating over Alaska and western Canada, brought northerlies exceeding 20 m s 1 and temperature decreases up to 15C over 24 h into Mexico and Central America. This paper addresses the multiscale aspects of the surge from the planetary scale to the mesoscale, focusing on 1) the structure and evolution of the leading edge of the cold surge, 2) the reasons for its extraordinary intensity and equatorward extent, and 3) the impact of the surge on the Tropics, specifically, on the strength of the trade winds and on the sea surface temperature in the eastern Pacific.