| Description |
The Tug Hill Plateau of upstate New York rises approximately 500 m above Lake Ontario, observes frequent (often heavy) lake-effect snowfall, and is one of the snowiest regions in the eastern United States. This work presents a climatology of lake-effect precipitation created using data from the KTYX WSR-88D radar situated atop the plateau. Base reflectivity imagery was manually examined to identify lake-effect periods (LEPs) during each cool season (16 Sep - 15 May) from 16 Sep 2001 - 15 May 2014. The most active months for lake effect in this region are December and January. There is a tendency for LEPs to begin within a few hours before and after sunset in the spring and fall, with no such diurnal signal observed in the winter. Correspondingly, lake effect is slightly more frequent at night than during the day. Overall, the diurnal variability is weaker than found over smaller bodies of water such as the Great Salt Lake of Utah. Classification of events by morphological type revealed that broad coverage and long-lake-axis-parallel (LLAP) account for ~72% and ~24% of lake-effect hours, respectively. The diurnal signal for broad coverage (LLAP) events was less (more) pronounced than for LEPs in general. The near-shore areas south and east of Lake Ontario receive the most frequent lake-effect precipitation. The Tug Hill Plateau produces a strong orographic signal, with an echo frequency maximum on the western (typically windward) slope. Data from cooperative observer (COOP) sites and the Snow Data Assimilation System (SNODAS) corroborate these radar-derived results. The ‘broadening' of high echo frequency over the Tug Hill Plateau, as well as the existence of the lake-orographic morphology, may point to inland/orographic intensification and generation of precipitation during some LEPs. |
