A Climatological Response of Weekly Surface Weather Observations in Nebraska After Drought Phase Transition

For an agricultural state like Nebraska, the economic, environmental, and social impacts of drought are severe. While precipitation is required to reduce drought conditions, the rate of drought improvement varies depending on both total precipitation over an area as well as antecedent soil conditions. To better understand the meteorological conditions that cause a region to transition to non-drought status, an analysis of the response of surface weather stations across Nebraska to drought transitions was conducted. A network of fifty-five Automated Weather Data Network (AWDN) stations divided between the eight individual climate divisions in Nebraska was used to generate a fifteen year climatological dataset of weekly observations. An analysis of these data was conducted for weeks when either the Palmer Drought Severity Index or Palmer Z Index transitioned from a negative anomaly (dry period) to a positive anomaly (wet period) by comparing the observations, which include precipitation, evapotranspiration, and soil moisture, with weekly improvements in the Palmer Drought Index and the Palmer Z Index. A statistical regression will be used in order to determine the relationship between index improvement and the observed variables. Characteristic results for each climate division will be generated and will provide a local representation of drought transition predictability.