In-situ Soil Moisture Coupled with Extreme Temperatures: A Study Based on the Oklahoma Mesonet

The relationship between observed (in-situ) soil moisture and percent hot days (%HD) in Oklahoma is examined using quantile regression. Consistent with results from previous modeling studies and observational studies using precipitation deficits as proxy, soil moisture is found to most strongly impact air temperature in the upper quantile of the %HD distribution. The utility of soil moisture for forecasting extreme heat events in Oklahoma is also assessed. Our results show that %HD can be predicted with reasonable skill using soil moisture anomalies from the previous month. These soil moisture-based forecasts of extreme temperature events can be used to support public health and water resource planning and mitigation activities in the Southern Great Plains region of the United States.