A Collaborative Approach to Study Northwest Flow Snow in The Southern Appalachians

Steve Keighton, Laurence Lee, Blair Holloway, David Hotz, Steven Zubrick, Jeffrey Hovis, Gary Votaw, L. Baker Perry, Gary Lackmann, Sandra E. Yuter, Charles Konrad, Douglas Miller (+1 others)
2009 Bulletin of The American Meteorological Society - (BAMS)  
N orthwest flow snow (NWFS) in the southern Appalachian region occurs during periods of moist, upslope flow in association with northwest low-level wind, often resulting in significant snowfall in the absence of synoptic-scale upward vertical motion. Very sharp snow accumulation gradients are created by the superposition of the synoptic-scale flow across the long, but rather narrow, mountain range and smaller-scale upward and downward motions induced by the numerous ridges and valleys
more » ... ng at various angles. Snowfall totals can range from a trace to over a meter from event to event or even within a single event. The highly variable nature of the snowfall in terms of duration, spatial distribution, and amount is such that observational and forecast techniques were not conducive to providing useful advance notice of these events until fairly recently. Frequently, forecasts of post-cold frontal weather mentioned only "snow flurries," which implied no accumulation. Indeed, flurries often occurred, but many events also included  Improved understanding and forecasting of northwest flow snow is the focus of a unique team of academic and operational colleagues from several universities and National Weather Service offices. Detail of an AVHRR false color satellite image. See Fig. 4 for more information.
doi:10.1175/2009bams2591.1 fatcat:qbhnnzs4hza3nnsajfarhtbnuu