Is there a "warming hole" in Eastern US equivalent temperature?

Several recent studies have investigated a period of cooling (or lack of warming) in the eastern United States, which is commonly referred to as a warming hole. The lack of warming has been attributed to disparate factors, such as atmospheric aerosols, feedbacks related to surface hydrology, and even large scale modes of climate variability. However, a clear definition of the warming hole (i.e., it’s temporal and spatial extent) has not been presented and potentially limits further exploration of physical drivers. Furthermore, the warming hole has traditionally been defined using air temperature, rather than alternative metrics, such as equivalent temperature, that combine temperature and humidity to better reflect the total heat content of the lower atmosphere. Here, we present initial results from an analysis that addresses both of these issues. Specifically, high resolution (4 km) monthly PRISM data are used to compute annual and summer (JJA) averages of air temperature and equivalent temperature for each year from 1948-2015. We then compute annual and summer temperature and equivalent trends for US regions using a range of start and end dates to better define the warming hole and determine whether it exists within an equivalent temperature framework.