THE IMPORTANCE OF THE EASTERN CANADA UPPER LOW AND CONFLUENCE FOR EAST COAST SNOWSTORMS
THE UPPER LOW NEAR THE MARITIMES HELPS TO HOLD THE UPPER LEVEL RIDGE AXIS NEAR THE GREAT LAKES REGION. THIS CONFIGURATION HOLDS CONFLUENT FLOW OVER THE NORTHEAST AND LOCKS THE SURFACE HIGH OVER THE NORTHEAST.
THE TRANSVERSE CIRCULATION ASSOCIATED WITH THE ENTRANCE REGION OF THE JET STREAK KEEPS LOW LEVEL NORTHERLY FLOW ALONG THE EAST COAST AND PROMOTES DAMMING
SHIFT THIS PATTERN TO THE WEST AND THE SAME PATTERN IS FAVORABLE FOR HEAVY SNOW OVER THE UPPER MIDWEST.
From Kocin and Uccellini, 1990