Exploring Winter Storm Watches from a National Perspective During the 2017 Winter Weather Experiment
Benjamin Albright, Systems Research Group, Inc. & NOAA/NWS/WPC, College Park, MD
Sarah Perfater, IM SYSTEMS GROUP, NOAA/NWS/WPC
Michael Bodner, NOAA/NWS/WPC
James Nelson, NOAA/NWS/WPC
Mark Klein, NOAA/NWS/WPC

Abstract
The 7th annual 2017 Winter Weather Experiment (WWE) took place over four weeks from January 17-19 and January 30-February 17, 2017 at the Weather Prediction Center’s (WPC) Hydrometeorology Testbed (HMT) in College Park, MD.  The experiment brought together researchers, modelers, and forecasters from across the country to explore experimental winter weather guidance and forecasting techniques.  For fiscal year 2017, WPC was tasked with an Analyze, Forecast, and Support (AFS) Office milestone of planning and prototyping a collaborative WPC and weather forecast office (WFO) Winter Storm Watch process.  Working toward this milestone, WWE participants practiced issuing two different types of winter storm watches throughout the experiment from a national perspective.

Participants used WPC’s watch collaborator tool during the creation of a traditional 24-hour Winter Storm Watch that covered the Day 2 period.  The WPC watch collaborator tool displays the probability that an area will exceed the local WFO watch criteria based on WPC’s probabilistic winter precipitation forecast (PWPF).  Participants also took into consideration where their Day 2 deterministic snow and ice forecasts exceeded local WFO snow/ice criteria when determining the watch area.  Winter Weather Alerts were the second type of watch issued and they again covered the Day 2 period but were not strictly tied to WFO snow/ice criteria and could be in effect less than 24 hours.  The alerts focused more on impactful events and/or multiple impacts that may get lost in a traditional 24 hour Winter Storm Watch.  Joint probability guidance created by WPC developers, which combined probabilities for snow, ice, temperature, and wind in various combinations in six hour intervals, were used heavily as guidance for these alerts.

This poster will show WPC’s first step in exploring a collaborative WPC-WFO Winter Storm Watch process.  Examples of both types of watches issued will be shown along with some of the guidance that was used to create them.  Finally, future steps and lessons learned will be discussed.