Examination of Mesoscale Feedbacks on Convective Scale Predictability during MPEX

A primary objective of the Mesoscale Predictability Experiment (MPEX) was to quantify upscale feedbacks from deep convection and assess the impact of these feedbacks on numerical model simulations. Analysis of upper air soundings collected during MPEX reiterate that surface cold pools are an effect of deep convection on the mesoscale environment that may persist for extended time periods. Arguably, appropriate representation of these cold pools is necessary for accurate prediction of severe convection occurring in multiday episodes because of the potential for cold pools to persist and significantly contribute to inhibition of surface-based convection.

Experiments employing the WRF-DART data assimilation system are used to examine this hypothesized relationship between cold pools and subsequent mesoscale-convective predictability. Data assimilation experiments are initialized at 15 UTC using NCAR ensemble data assimilation system analyses. Assimilation cycling occurs from 16 UTC to 03 UTC before launching forecasts. In these experiments, surface observations and radar reflectivity data are assimilated onto a 3 km convection-permitting domain. Furthermore, suppression of convective development will be attempted by assimilating radar reflectivity data that have been edited to remove convective storms. Aspects of the mesoscale environment will be verified with a focus on the supplemental MPEX observations, and characteristics of severe convection will be verified using conventional observations and radar data.