Comparing In Situ Boundary Layer Measurements to High-Resolution Model Output

Understanding the boundary layer is critical to understanding the earth-ocean-atmosphere system and improve forecasts of turbulence, air quality, severe weather, and other atmospheric phenomena. Improved measurements within the boundary layer have the potential to significantly benefit the BL meteorology community.

Throughout 2018, we traveled around the country to visit universities with meteorology programs and meteorologically-related research interests as part of a radiosonde roadshow. At the end of each visit, the students assisted in launching a radiosonde. We launch radiosondes from our office in Louisville, Colorado, in association with customer visits and training, employee training, and in cases of hazardous weather potential. These flights give dozens of radiosonde flights from many regions of the country to analyze.

High resolution proximity model soundings from convection allowing models (e.g., HRRR, RAP) were downloaded for the same UTC hour as the balloon launch (1647 UTC = 17 UTC, for example). We plot the model sounding and the actual sounding on the same Skew-T diagram and compare the two boundary layers. Even at the resolutions of convection allowing models, in-situ soundings provide significantly more detail and accurate representations of the boundary layer. For operational forecasters, this additional detail in the boundary layer can prove useful during challenging forecasts.

This poster compares both model profiles and calculated parameters from soundings in different regions and different weather regimes. It shows the importance of not relying solely on model data to understand the boundary layer.