Preliminary assessment of timing differences between convective initiation and severe initiation

Using a similar definition for convective initiation (CI) as was used during the 2012 Spring Forecasting Experiment (SFE), the time between CI and severe storm initiation (SI) was studied. This time interval can be of importance to operational severe weather forecasting and warning activities, yet this topic has not yet been systematically explored. Fifteen cases of observed “clean-slate” afternoon CI occurring across the CONUS (with a bias toward the Great Plains) during the spring of 2011 were collected for the initial sample. Storm objects based on observed radar attributes were tracked through space and time, and matched to local storm reports (LSRs) to determine the elapsed time between their initiation and when they first produced a severe report to the nearest 15 min. Histograms and probability distribution functions (PDFs) of timing difference between CI and SI are presented, separated by LSR type. Given the increase in radar based attributes and detection of severe storms, and the increase in the ability of convection allowing models to predict convective storms, exploring SI gives yet another avenue for extracting information from models that can be used for verification.