Analysis of End User Access of Warn-on-Forecast Guidance Products during an Experimental Forecasting Task Weather, Climate, and Society

Convection-allowing model ensemble guidance, such as that provided by the Warn-on-Forecast System (WoFS), is designed to provide predictions of individual thunderstorm hazards within the next 0–6 h. The WoFS web viewer provides a large suite of storm and environmental attribute products, but the applicability of these products to the National Weather Service forecast process has not been objectively documented. Therefore, this study describes an experimental forecasting task designed to investigate what WoFS products forecasters accessed and how they accessed them for a total of 26 cases (comprising 13 weather events, each worked by two forecasters). Analysis of web access log data revealed that, in all 26 cases, product accesses were dominated in the reflectivity, rotation, hail, and surface wind categories. However, the number of different product types viewed and the number of transitions between products varied in each case. Therefore, the Levenshtein (edit distance) method was used to compute similarity scores across all 26 cases, which helped to identify what it meant for relatively similar versus dissimilar navigation of WoFS products. The Spearman’s rank correlation coefficient R results found that forecasters working the same weather event had higher similarity scores for events that produced more tornado reports and for events in which forecasters had higher performance scores. The findings from this study will influence subsequent efforts for further improving WoFS products and developing an efficient and effective user interface for operational applications. 2021 Atmosphere Social Science Ensembles Forecasting Forecasting techniques Numerical weather prediction/forecasting Operational forecasting Probability forecasts/models/distribution OAR (Oceanic and Atmospheric Research) NSSL (National Severe Storms Laboratory) CIMMS (Cooperative Institute for Mesoscale Meteorological Studies) NWS (National Weather Service) SPC (Storm Prediction Center) Submitted https://doi.org/10.1175/WCAS-D-20-0175.1 Other 1948