A Case Study of a Mesoscale Vorticity Center

On the afternoon of July 11,1987 a weak short wave moved east through the Ottawa valley of Quebec and Ontario. It appeared to be the triggering mechanism for a convective cluster, that moved through the Ottawa Valley, and into the St. Lawrence Valley of New York during the late evening. The convective cluster then moved south into the Adirondack region. This cluster produced a " Mesoscale Vorticity Center" (MVC) (Johnston, E.C.-1982), which appeared to be the triggering mechanism for a convective outbreak and 2 severe storms over eastern New York the afternoon of July 12th. This paper is a case study of the event, and how satellite interpretation was used in locating the MVC, and outflow boundaries in real time at the WSFO.