Exploring the Relationship Between Monthly Climate Variation and Extreme Heat Index Event Frequency in the Southern United States

This study aims to explore the relationship between the frequency of extreme heat index events in the southern United States and climate variation as indicated by various climate indices.  Local data used for this analysis comes from ASOS airport ground stations and climate index data is taken from the National Weather Service’s Climate Prediction Center (CPC).  Five indices will be used for analysis:  the Pacific North American Index (PNA), the North Atlantic Oscillation (NAO), the Southern Oscillation Index (SOI), the Tropical Northern Atlantic Index (TNA), and the Pacific Decadal Oscillation (PDO).  Analysis will cover June through September over a 68-year period from 1948 – 2016.  A peak-over-threshold method will be used to identify heat index events, and multivariable linear regression will be used to explore the overall relationship.