Comparing distributions of overshooting convection in HRRR forecasts to observations

These distributions show mean, median, and maximum echo tops 2-3 km lower than observations, both in absolute and tropopause-relative space, with evidence of updrafts losing momentum too rapidly above the tropopause. Diurnal cycles show accurate times of maximum and minimum overshooting, but significant errors at model initialization and evidence that some simulated overshoots continue too late into the overnight hours.

Despite these deficiencies, distributions of simulated levels of maximum detrainment show decent agreement with observations. All results, including the severe underprediction of echo top heights, persist at shorter forecast lead times. This indicates a need to improve representation of overshooting storms in weather and climate models, even those that are convection-permitting, or introduce a transport parameterization.