While the general winter effects of the El Nino-Southern Oscillation (ENSO),North Atlantic Oscillation (NAO), Arctic Oscillation (AO), and Pacific Decadal Oscillation (PDO) in the Ohio and Tennessee Valleys are known, this study digs deeper into the analysis of how the phenomena work in synergy to modulate winter weather conditions in the area. In an effort to develop a climatology-based forecasting tool, historical temperature, precipitation, and snowfall data since 1950 were analyzed in comparison to different phases of these larger circulation patterns. This analysis was performed for 123 Local Climatological Data (LCD) and Cooperative Observer Program (COOP) sites within the area of study. The study utilized many resources, including xmACIS2, the Local Climate Analysis Tool (LCAT), Climate Prediction Center (CPC) database, R statistical software, and ESRI Geographic Information System (GIS) programs.
The first phase of the project calculated standard deviations and averages for each station and weather variable in the study region. Results highlighted the importance of considering the joint effects of larger circulation patterns on seasonal prediction, as they can either reinforce the effects, cancel out the impacts, or have no effect on future prediction. These results fostered a curiosity in quantifying the impact of each larger circulation pattern on the wintertime weather of the Ohio and Tennessee Valleys. We hypothesize that a certain combination of these patterns will be able to give significant indications of the typical weather patterns of the area of interest and any potential for dangerous weather in the upcoming seasons.
This multi-faceted study will allow forecasters to identify upcoming seasonal trends to facilitate a Weather-Ready Nation by answering customer questions as they prepare for unique cyclical weather challenges. In addition, forecasters will be better equipped to anticipate day-to-day weather patterns and storm behavior based on ENSO and NAO phase combinations to enhance user decision support
