Influence of Northern Hemisphere Teleconnections on ENSO-Related Precipitation Patterns in the US (2013)

Undergraduate: Melissa Wrzesien

Faculty Advisor: Erika Wise
Department: Environmental Science

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Weather forecasts frequently cite the El Ni¿o−Southern Oscillation (ENSO) when projecting whether a region will experience wetter or drier than normal conditions. However, ENSO ¿ and other teleconnection patterns ¿ do not occur in isolation. While El Ni¿o is typically associated with increased precipitation in the southwestern portion of the United States, the presence of other teleconnection patterns could strengthen or weaken the expected precipitation signal. The North Atlantic Oscillation (NAO) has also been featured in weather forecasts in recent years since its negative phase leads to colder temperatures and snowy conditions in the eastern United States. The objective of this study is to determine the consistency of those impact patterns across the United States. How do ENSO and NAO interact? What are the spatial patterns of precipitation when other Northern Hemisphere teleconnections are taken into account? How can these spatial patterns be used to improve medium- or long-range forecasts based on these oscillations? We correlated a precipitation dataset (PRISM) with various teleconnection indices to see which regions are anomalously dry or wet. We anticipate that seasonal predictions of precipitation could be improved through incorporating multiple climate modes in a regional forecast. A focus on regionally important indices by weather forecasters could also serve as an educational tool concerning the complexity of the climate system.