Analysis of data from the entire OWLeS period, individual cases, and 13 years of lake-effect periods identified by Veals and Steenburgh (2015), suggest that some key factors controlling enhancement include the strength of the cross barrier flow (i.e., the mean 975–850 hPa zonal wind speed) and the lake-induced low-level instability (evaluated using the difference between the mean lake surface temperature and the 850 hPa temperature). Higher wind speeds produce greater inland penetration of precipitation and more persistent precipitation over the plateau. In contrast, during weak flow, precipitation is largely confined to the lower slopes and near the lake shore. Low instability values favor a confinement of echoes to the plateau and inland areas, while high values favor areas closer to the shore and over the lake. Individual cases, however, exhibit significant variability in the effect of these variables on precipitation enhancement.
These results, along with ongoing analysis of the influence of lake-effect mode, capping inversion height, and other factors, help illustrate the mechanisms controlling the distribution of lake-effect precipitation in areas of complex terrain, with important implications for operational weather forecasting.