The Winter Storm Severity Index at the Weather Prediction Center (57)
Joshua Kastman, CIRES/WPC, College Park, MD
James Nelson, WPC
Mark Klein, WPC
Sarah Perfater, IMSG/WPC
Beginning in October 2017 The Weather Prediction Center (WPC) took over responsibilities for the running the Winter Storm Severity Index (WSSI) from the National Weather Service (NWS) Burlington, VT weather forecast office (WFO). This was done to provide a more stable processing environment with increased computer and development resources. The WSSI is a tool designed to assist NWS operational forecasters in maintaining situational awareness of the possible significance of winter weather related impacts based upon the current official forecast.
The WSSI is achieved through the use of Geographic Information Systems (GIS) by screening the official National Weather Service gridded forecasts from the National Digital Forecast Database (NDFD) for winter weather elements and combining those data with non-meteorological or static information datasets (e.g., climatology, land-use, population) to create a graphical depiction of anticipated overall impacts to society due to winter weather. The WSSI has been developed to have a two-fold focus. One is as a tool to assist NWS operational forecasters in maintaining situational awareness of the possible significance of weather related impacts based upon the current official forecast. The second is to enhance communication to external partners, media and general public of the expected severity (potential societal impacts) and spatial distribution of winter weather.
Focus will be paid to ongoing developments of the WSSI at WPC. These developments include breaking the WSSI into 24 hours periods from the total 72 hour summary, including additional parameters (apparent temperature, wind speed and snow rates) and making the data available in GIS formats (KML, Shapefiles). Some examples from the 2017-2018 winter will be shown to highlight strengths and areas needing improvement.