First Guess Fields for WPC's Day 3-7 Hazardous Heat Outlook

First Guess Fields for WPC’s Day 3-7 Hazardous Heat Outlook

Zoe Benitez

Mark Klein, Bryan Putnam, Allison Santorelli

NWS, Weather Prediction Center

National Oceanic and Atmospheric Administration (NOAA)

The Weather Prediction Center is responsible for generating the Day 3-7 Hazards Outlook, which illustrates the location and duration of weather-related threats to operations, life, and property across the United States. Prevalent among these threats is Hazardous Heat, defined in the Hazards Outlook as a probability greater than 40% of exceeding widespread National Weather Service Heat Advisory Criteria. The criteria referenced are specific to the climatology of the region at the county level. First Guess Fields for the spatial and time scales of hazards are a vital tool that increase forecaster efficiency by summarizing data visually in a probabilistic format to highlight regions of interest and concentrate the efforts of skilled labor in operations. To create such fields, this project gathers data from the experimental NWS HeatRisk product, the Extreme Forecast Index (EFI) from the European Centre for Medium-Range Weather Forecasts, and Heat Index calculated from ensemble model forecasts. These datasets are analyzed probabilistically to produce a union where EFI exceeds 0.8, HeatRisk is Major or Extreme, or the Heat Index shows greater than a 40% chance of exceeding Heat Advisory Criteria. Ensemble data is collected from the Global Ensemble Forecast System, Global Ensemble Prediction System, and the Ensemble Prediction System models for multiple valid forecast hours per day and probabilities are calculated according to the fraction of ensemble members exceeding Heat Advisory Criteria for the valid forecast hour corresponding to the daily maximum heat index value. Information throughout the project is synthesized in interactive graphics layers in ArcGIS Pro and ArcMAP, the softwares currently employed by forecasters to generate the hazards product. These graphics were designed with color choices to intuitively emphasize the most relevant information while blending with the convention for existing products. This presentation will focus on the visualizations of Hazardous Heat developed for WPC, both for current operational products and newly developed probabilistic guidance.