A spatiotemporal assessment of Tornado Warnings within Storm Prediction Center Convective Outlooks using Geographic Information Systems

The Storm Prediction Center (SPC) is tasked with monitoring, evaluating, and forecasting for severe weather over the continental United States. One product issued in particular is the SPC Convective Outlook, providing a narrative and spatial overview of locations where the threat for severe thunderstorms exist. The “polygon-based” tornado warning system National Weather Service (NWS) local offices use to delineate warned area based on the spatiotemporal estimates of threat locations. These warnings allow a forecaster to define and disseminate information with greater accuracy and clarity than the predecessor “county-based” warning system.

This study provides an empirical analysis of Tornado Warning spatial characteristics within different SPC risk classes. A 2 year dataset, January 1st, 2008 – January 1st, 2010, of polygon-based tornado warnings and SPC Day 1 Outlooks will be plotted together in a geospatial domain. All warnings will be classified within a specific SPC threat category, their spatial attributes will be extracted, and the resulting trends will be investigated.