NOAA/NWS Western Region Experimental HeatRisk Project: Providing A New Heat Service for a WRN

Heat kills more people than any other weather phenomenon across the nation. In the NOAA/National Weather Service’s (NWS) Western Region (WR), heat kills more people annually than floods, lightning, and tornadoes combined. However, unlike with most high impact weather phenomenon, criteria and methodologies for issuing heat watches, warnings, and advisories vary significantly across NOAA/NWS Weather Forecast Offices (WFOs). This inconsistency results in a patchwork of heat products, sometimes within the same state, causing confusion and frustration from decision makers charged with response efforts. Additionally, it is becoming increasingly evident that any approach that attempts to create a single threshold that adequately addresses the diversity of decision points related to heat is challenging, if not impossible.

In 2013, the State of California Office of Emergency Services (CA OES) specifically requested a new and consistent approach to heat event identification and notification from NWS/WR for the state of California. To address the issues in our current approach toward heat event identification and to provide the increasing level of Decision Support Services demanded of the NOAA/NWS by its partners and customers, a multi-tiered framework was created to identify potential heat risk. This framework applies a consistent methodology nationwide, incorporating high-resolution local climatology and peer-reviewed heat science, to place forecast heat into a numeric and color-based heat risk system. This context can be useful for both identifying unusual heat in the upcoming forecast, and to place historical impacts into a probabilistic risk profile that can be useful to decision makers to take action. This unique approach was introduced across the WR in 2014 and has received positive reaction from many of those introduced to it over the past three heat seasons, including CA OES.

This presentation will introduce the NWS experimental HeatRisk Project. A high-level overview of the approach and the science used will be provided, along with feedback from several heat health partners and CA OES. This approach is expandable nationwide, with several offices in the Central and Southern Regions of the NWS testing out the approach over past heat seasons. Feedback from NWS offices outside WR will also be included in this presentation.