Syracuse University SURFACE Dissertations - ALL SURFACE December 2019 Snowstorms in Upstate New York: synoptics, spatial modeling and temporal variability Justin Joseph Hartnett Syracuse University Follow this and additional works at: https://surface.syr.edu/etd Part of the Social and Behavioral Sciences Commons Recommended Citation Hartnett, Justin Joseph, "Snowstorms in Upstate New York: synoptics, spatial modeling and temporal variability" (2019). Dissertations - ALL. 1120. https://surface.syr.edu/etd/1120 This Dissertation is brought to you for free and open access by the SURFACE at SURFACE. It has been accepted for inclusion in Dissertations - ALL by an authorized administrator of SURFACE. For more information, please contact [email protected]. ABSTRACT This dissertation examines the characteristics of snowstorms that affect Central New York, a subsection of the eastern Great Lakes region, in a series of chapters organized as journal articles. The first article develops a classification scheme to categorize snowstorms in Central New York from the 1985/86 season to the 2014/15 season. Twelve different snowstorm types were classified by their connection to the Great Lakes, the presence or absence of a synoptic low, or their area of cyclogenesis. The second article uses the 2055 classified snowstorms to examine their relative contribution to seasonal snowfall totals. Although lake-effect snowstorms are the dominant snowfall contributor for most of Central New York, their contributions vary considerably across the region. These storms contribute approximately 50% of the seasonal snowfall totals in the Tug Hill, and only about 25% in southeastern Central New York. Instead, Nor’easters are the dominant snowfall contributor in southeastern Central New York. Model results can accurately estimate seasonal snowfall contributions using a location’s latitude, longitude, elevation and distance from the lake, or its latitude, longitude, and 5 km elevation exposure. The third article examines the typical snowfall distributions and synoptic conditions associated with the different snowstorms. Localized snowfall patterns are most common when there is a surface high pressure over the United States and a low over northeastern Canada. This setup combined with cold air (< 20˚C), often initiates the formation of lake- effect or lake-enhanced snow, potentially leading to the localized snowfall patterns. Regional-wide snowfall was most common with cyclonic snowstorms (Nor’easters and Rocky lows). These storms are often associated with an omega-blocking pattern, and heavier snowfall is common when air trajectories pass directly over the long-axis of Lake Ontario. The fourth and fifth articles examine how snowfall totals for the different snowstorm types have changed over time, and potential causes for these changes. This is the first study to directly assess seasonal snowfall trends for individual snowstorm types. Lake-effect snowfall significantly ( ≤ 0.05) increased in areas furthest from the lake from 1985/86 – 2014/15, while snowfall from clippers decreased across the entire region. Snowfall from lake snowstorms also increased in Region 3, but trends were inconsistent. Snowfall significantly increased in the late-1980s and late 1990s, but significantly decreased in the mid-1990s. The variability in trends may be linked to environmental conditions, as air temperatures were incorporated in 21/35 of the significant models. The Great Lakes also influenced seasonal snowfall totals mostly in Regions 1 and 3, while precipitation and average temperatures are the most influential factors in Regions 4 and 5. Teleconnections affect seasonal snowfall the most for Nor’easters, as above normal snowfall often occurs with the positive phases of the AO and PDO and the negative phase of the NAO. Lake-effect snowfall is mostly influenced by the WP, while teleconnections in the Atlantic Ocean and Arctic largely affect snowfall totals from storms originating in western Canada. Together, these articles highlight the importance of examining individual snowstorm types in the Great Lakes region and showcase potential forcings behind seasonal variations. This study also highlights the importance of understanding the seasonal snowfall contribution of different snowstorm types and how it is changing, so that accurate predictions can be made for future climate scenarios. SNOWSTORMS IN UPSTATE NEW YORK: SYNOPTICS, SPATIAL MODELING AND TEMPORAL VARIABILITY by Justin Joseph Hartnett B.S., Coastal Carolina University, 2011 M.S., University of South Florida, 2013 DISSERTATION Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Geography Syracuse University December 2019 Copyright © Justin J. Hartnett 2019 All Rights Reserved ACKNOWLEDGEMENTS This work has been a long, arduous process, one that could not have been completed without the help from a number of people. First, I would like to thank all the people that have helped mold this work and my education. I would especially like to thank Jennifer Collins for always believing in me and helping me become the successful academic I am today. Your guidance has been invaluable, and I cannot thank you enough for it. To my advisor, Susan Millar, thank you for all the guidance on this work and the countless hours spent reading it and providing feedback. I am proud of this work, and you helped shaped it tremendously. To Wendy Lascell and those at SUNY Oneonta that gave me a chance to thrive as an educator and helped mold my dissertation, I thank you as well. Oneonta has taught me so much on how to be an academic and I cherish all the connections I have made so far. I would also like to thank Jake Bendix who has acted as my second advisor throughout this process. I appreciate all the work that we have done together, but more importantly the mentoring that you provided me. This dissertation has also been enriched immensely by my committee members Adam Burnett, Peng Gao, and Jane Read. I especially want to thank Adam and Art Samel for all of their insights into lake-effect and for taking me under their tutorage. I would like to thank all the people that have supported me through this process. Without each and every one of you, I would not have accomplished this tremendous feat. I could not have asked for better friends to surround myself with, encouraging me and helping me through the process. I especially want to thank Emily Bukowski, Pat Oberle, and Maddy Hamlin for all the conversations, venting sessions, and fun times that we’ve had. I would also like to thank everyone that helped me enjoy my time at Syracuse including Forrest Young, Joe (Philly) Hunter, Alyssa Almeida, Erik and Tori, Maeve Lanning, the Santoferrara family, and many more. All of you helped provide some sanity throughout this process. Lastly, I want to give a special thank you to my family. Thank you to everyone that has supported me through this process, while also helping me enjoy it. Thanks to all my cousins, aunts and uncles, and grandparents. I especially want to thank my parents, Ted and Chrissy, for always supporting me and giving me the tools necessary to succeed in life. Thank you to my brother, Derrick, for always being my inspiration. To Jerry and Sulley, I cannot thank you two enough for putting up with my stress, late-night sessions, and sitting in front of the computer for countless hours. I appreciate everything that you both did for me to keep me sane and I love you more than can be described. I can gladly say that it is now over, and it would not have been possible without any of you. vi TABLE OF CONTENTS List of Tables ........................................................................................................................................... x List of Figures ....................................................................................................................................... xii Chapter 1: Introduction ......................................................................................................... 1 1.1 Purpose of the Research ................................................................................................. 8 1.1.1 Resolving the Percent Contribution of Lake-Effect Snow to Seasonal Snowfall Totals ..................................................................... 8 1.1.2 The Influence of Atmospheric Variability on Snowfall Contributions ............................................................................................. 11 1.1.3 Storm Trajectories .................................................................................... 14 1.1.4 Historical Snowfall Trends .................................................................... 16 1.1.5 The Influence of External on Forcings on Seasonal Snowfall Contributions .......................................................................... 19 1.1.6 The Influence of Internal Forcings on Seasonal Snowfall Contributions .............................................................................................. 22 1.2 Research Objectives ....................................................................................................... 27 Chapter 2: Data and Methods ............................................................................................ 29 2.1 Study Area ......................................................................................................................... 29 2.2 Snowstorm Identification and Magnitude ...........................................................