The Importance of Soil‐Type Contrast in Modulating August Precipitation Distribution Near the Edwards Plateau and Balcones Escarpment in Texas

Abstract

The Balcones Escarpment in central Texas is a sloped region between the Edwards Plateau and the coastal plain. The metropolitan areas located along the Balcones Escarpment (e.g., San Antonio, Austin, and Dallas‐Fort Worth) are prone to heavy rain and devastating flood events. While the associated hydrological issues of the Balcones Escarpment have been extensively studied, the meteorological impacts of the Edwards Plateau and Balcones Escarpment are not well understood. The indeterminate impacts of the thermal and dynamic effects of the Edwards Plateau on August climatological precipitation are investigated in this study using the multisensor Stage IV precipitation data, high‐resolution dynamic downscaling, and short‐term sensitivity simulations. Analysis results indicate that the total August precipitation east of the Balcones Escarpment is suppressed and precipitation over the eastern part of the Edwards Plateau is enhanced. Locally initiated moist convection in the afternoon contributes most to the total precipitation during August in the region. The dynamic downscaling output captures the spatial pattern of afternoon precipitation, which is well aligned with the simulated upward motions. The clay‐based soil types that dominate the Edwards Plateau have great potential to retain soil moisture and limit latent heat fluxes, consequently leading to higher sensible heat flux than over the plain to the east. As a result, vertical motion is induced, triggering the afternoon moist convection over the Edwards Plateau under favorable conditions. In comparison, the sloping terrain plays a smaller role in triggering the convection. Short‐term sensitivity simulations for a clear day confirm and further prove such a diagnosis.

Precipitation Dynamical Downscaling Over the Great Plains

“…In the absence of a true fix to the model bias, one possible solution to prevent the systematic solution drift is to nudge the large‐scale fields within the simulation domain toward the external forcing. Interior nudging had proven successful previously in dynamical downscaling of regional climate (Hu et al, ; Huang et al, ; Mabuchi et al, ; Miguez‐Macho et al, ; Lo et al, ; Liu et al, ; Paul et al, ; Prein et al, ; Spero et al, ; von Storch et al, ). WRF supports two forms of interior nudging: analysis nudging (also called “grid nudging”) and spectral nudging (Miguez‐Macho et al, ; Wang & Kotamarthi, ).…”

Meteorological Conditions During an Ozone Episode in Dallas‐Fort Worth, Texas, and Impact of Their Modeling Uncertainties on Air Quality Prediction

“…The Noah land surface scheme (Chen & Dudhia, ) coupled with a single‐layer urban canopy model (Kusaka et al, ) is used to simulate land surface processes. Such a configuration was demonstrated to capture the thermodynamic and dynamic effects of urban areas in the Southern Great Plains quite well (Hu et al, ; Hu & Xue, ). The urban land use categories (Figure b) are derived from the National Land Cover Data 2011 (Homer et al, ), in which the urban land use is divided into three categories: low‐intensity residential (31), high‐intensity residential (32), and commercial/industrial (33).…”

Dynamical Downscaling of CO2 in 2016 Over the Contiguous United States Using WRF‐VPRM, a Weather‐Biosphere‐Online‐Coupled Model

“…Sun et al, 2016). We adopted the WRF dynamic downscaling configurations of our previous studies (Hu et al, 2017; Hu, Xue, et al, 2018) that have been shown to produce accurate downscaled climate over CONUS. The model domain has 47 vertical layers extending from the surface to 10 hPa.…”