Abstract
A climatology of severe weather outbreaks occurring in areas of the contiguous United States where the mid-troposphere flow has a north of west component has been developed for the period 1962–77. During the 16 years, 163 outbreaks of severe weather have been identified that fit a specific set of criteria for “northwest flow”. Analyses of this data set reveal the diurnal, seasonal and geographical frequencies and characteristics of this phenomenon. The nature of “northwest flow” outbreaks is examined in relation to the effect on life and property.
