Can an Impact-Based Forecast Product Help Communicate Risk of Severe Winter Weather in Alaska?

The Winter Storm Severity Index (WSSI) is an operational product for the continental United States at the Weather Prediction Center (WPC) that identifies the severity of potential impacts of an impending winter storm integrating components such as snow amount, ice accumulation, snow load, flash freeze, ground blizzard, and blowing snow. WSSI was developed in response to user needs for easily consumable forecast information and has been the focus of social science research to improve its design and utility. Previous efforts had been focused on CONUS but recent interest in extending the WSSI to Alaska spurred a new social science research study to investigate the distinct needs of Alaska that require different and additional components. This study sought to investigate how the WSSI components could align with the needs of Alaska Region stakeholders, and how the product’s definitions of and categorization of impacts could align with expectations surrounding impact severity levels (extreme, major, moderate, minor, etc.). Additionally, the study provided recommendations to WPC for product development and design and supported transition to operations, while developing lessons learned for adapting a national product to region-specific needs, findings that might inform other NWS product development.

Working towards achieving these goals, the Nurture Nature Center (NNC) and WPC/CIRES met with Alaska Weather Forecast Office (WFO) representatives from Fairbanks, Juneau, and Anchorage, along with other project partners to develop focus group scenarios specific to each of six regions: West Coast, Southwest/Bristol Bay, Southcentral/Anchorage, North Slope, Juneau, and Fairbanks. Scenarios were developed around severe weather events and the WFOs contributed briefings and other NWS products to build out the timelines of storm progression, while NNC created mocked-up versions of WSSI for Alaska for inclusion in the scenarios.

Six virtual focus groups were held in June 2022, recruiting stakeholders from each region including representatives from emergency management, transportation, aviation, schools, and more. Focus group participants completed pre- and post-session surveys and participated in a two-hour discussion about preparedness, actions, understanding, needs, and challenges associated with the forecasted weather and presented products. Data collected helped build understanding about the needs for weather forecasting products and what impacts matter the most to each of the regions, with a focus on the Alaska WSSI product and legend detail. The focus group transcripts and surveys were analyzed and shared with WPC to inform the development of a prototype Alaska WSSI product (with three case studies created: snow amount, ice accumulation, and freezing spray events). This prototype was tested with an online survey completed by previous focus group participants as well as new stakeholders identified by WFO partners. In addition, the prototype was tested in the 2023 Arctic Testbed and Proving Ground held in November in Anchorage, AK with forecaster representatives from the Alaska WFOs.

Overall findings suggest a strong need for inclusion of wind direction and speed, and the adaptation of impact category descriptions specific for Alaska (less emphasis on roads and more concern about visibility). Stakeholders and forecasters saw value in the WSSI Alaska product especially for providing situational awareness and a heads-up for where to focus attention, crucial for covering the large forecast areas in Alaska.

This presentation will describe how a user-informed and tested impact-based forecast product can inform risk communication of impending winter weather and meet the unique climate considerations of the various Alaskan regions. An overview of the methodology and iterative approach, along with findings will be shared along with key takeaways concerning how such a process can improve product design, understanding of communication challenges, and ultimately risk communication to end users.