National Weather Service Issuance of Polygon-Based Snow Squall Warnings and Dust Storm Warnings and Dust Advisories for High-Impact Events

Snow Squalls and Dust Storms are unique, extremely localized extreme weather events that can result in high impact to the public and commerce. Previously, hazard messages for these events had been issued via generic Special Weather Statements (SPS) that are not enabled by Valid Time Event Code (VTEC) nor are their respective Common Alerting Protocol (CAP) elements populated with values which would foster enhanced dissemination. In sharp contrast, these new products are short-fused, polygon-based, and leverage VTEC and CAP to facilitate dissemination, achieve more widespread distribution, and effective Decision Support Service.

There has been a long-standing need for the National Weather Service (NWS) to effectively disseminate this highly-localized information to our partners who depend upon VTEC and CAP to recognize and parse our warning products for their customers. In addition, the capability to define localized areas of threat (e.g., as is available for severe thunderstorms, tornadoes, and flash floods through the use of NWS WarnGen software) improves communication to the public via Wireless Emergency Alerts (WEA) and dissemination via the Emergency Alert System (EAS). The polygon-based Snow Squall Warning (VTEC code SQ.W) and Dust Storm Warning and Dust Advisory products (VTEC codes DS.W and DS.Y, respectively) provide critical, life-saving information for these short-term, highly localized, extreme hazardous events to our partners in machine-readable formats, and enables our users to parse the products and make them available to their customers.

During January 2018, the NWS began an operational demonstration for the highly localized Snow Squall Warning at the following six Weather Forecast Offices (WFOs): Binghamton NY, Burlington VT, Cheyenne WY, Detroit MI, Pittsburgh and State College, PA. The first issuances occurred at the Binghamton, NY WFO on February 2nd. The operational demonstration for the highly localized Dust Storm Warning and Dust Advisory began during Spring 2018 at WFOs Phoenix and Tucson, AZ. The software which provides the capability to issue these products was then implemented in a phased manner to all NWS applicable offices through the end of 2018.