Analysis and Verification of 1300 UTC Storm Prediction Center Convective Outlooks

Storm Prediction Center (SPC) convective outlooks for severe weather, specifically tornadoes often are utilized (among other resources) for the determination of target areas by severe weather researchers as well as storm observers and spotters. Convective outlooks issued at 1300 UTC from 23 January 2003 through 31 December 2013 were examined and outlooks that called for a 10% or greater chance of tornadoes within 25 miles of a point were included in the analysis, along with all categorical moderate and high-risk outlooks. These outlooks were examined qualitatively for verification purposes; if the number and density of tornado reports agreed well with the geographic area outlined by the SPC for a heightened risk of tornadoes, that outlook was considered a successful forecast. If the number or density of tornado reports did not agree well with the geographic area outlined by the SPC, however, that forecast was considered to be an unsuccessful forecast. For such events, additional analysis of radar and satellite imagery, surface observations, and upper-air data will be completed to determine the likely mode of failure for these forecasts. It is hypothesized that common modes of failure will include lack of significant surface-based convection within the outlook area and lack of expected convective mode (convection took the form of lines as opposed to discrete cells). Statistics on these modes of failure will also be presented in an effort to help improve future forecasts for these difficult forecast situations.