Snow-fall event climatology: The finale

TitleSnow-fall event climatology: The finale
Publication TypeConference Proceedings
Year of Conference1992
AuthorsMahoney, J. L., and Brown J. M.
Conference Name60th Annual Western Snow Conference
Series TitleProceedings of the 60th Annual Western Snow Conference
Date PublishedApril 1992
PublisherWestern Snow Conference
Conference LocationJackson Hole, Wyoming
KeywordsClimatology, Colorado winter storms, Snowfall event, Synoptic scale patterns

Two distinct types of snowfall events that produce heavy snow along the Front Range of Colorado are discussed in Part 2 of the snowfall-event climatology. A 40-year snowfall-event archive was used as the basis for the study. The additional analyses of synoptic surface and upper air maps, soundings and quasi-geostrophic diagnostics led to the identification of two distinct synoptic patterns, which we shall refer to as a Four Corners Low and a Southeast Colorado Low.The Four Corners Lows were characterized by surface high pressure of arctic regions to the north of Colorado with a cyclone to the southwest of the state, shallow upslope below 700 mb capped by an inversion layer with southwesterly winds above, and lack of synoptic-scale forcing of vertical motion. The Southeast Colorado Lows featured an intense surface cyclone over the southern High Plains associated with a strong upper trough or closed low, deep upslope flow over northeast Colorado, a jet from the northeast quadrant 750 and 500 mb, and strong vertical coherence in the synoptic-scale forcing of vertical motion. We will present examples of each synoptic.