Before supercell thunderstorms initiated on 16 May, NEWS-e output depicted dangerous storms forming and moving toward western Oklahoma. This output was displayed on WFO Norman’s situational awareness display, and a University of Oklahoma Cooperative Institute for Mesoscale Meteorological Studies scientist provided a briefing on the guidance in the operations area. Once storms developed, NEWS-e contributed to a high degree of forecast confidence that the storms would become long-lived supercells with a risk of tornadoes. Based on output from NEWS-e, WFO Norman issued an advisory stating “a high probability that tornado warnings will be issued” for parts of four counties in western Oklahoma nearly two hours before the deadly tornado struck Elk City.
This use of NEWS-e demonstrates the feasibility of the proposed Forecasting a Continuum of Environmental Threats (FACETs) approach whereby forecasters can elevate tornado probabilities well downstream from legacy warning polygons, giving greater advance notice. NWS forecasters and NSSL researchers have been testing these concepts in the Hazardous Weather Testbed since 2015.