Anna Wanless - April 14

Weather and Climate Systems Seminar

Examining Extreme Rainfall Forecast and Communication Processes in the South Central United States

Anna Wanless

Wednesday, April 14^th

2:00 pm

Join Google Meet:

https://meet.google.com/jdv-kpfr-gnu

Extreme rainfall events have increased in parts of the country and climate models project that trend to continue. As such, forecasters must be able to effectively communicate the potential threats and impacts associated with these events to their users. How National Weather Service (NWS) meteorologists and hydrologists communicate with their audiences leading up to and during extreme rainfall events has not yet been widely explored. This study aims to help address that knowledge gap.

This research investigated how NWS forecasters processed and communicated information about extreme rainfall events that occurred in the South-Central U.S. between 2015 and 2019. An event was included in this study if the NWS Hydrometeorological Design Studies Center determined it to have an Annual Exceedance Probability of 1/500 or less. Therefore, nine events were included. Semi-structured interviews were conducted with 21 NWS forecasters about their experiences with the events and how they or their offices messaged the event. Study participants were asked event-specific questions about products disseminated by their offices leading up to and during the event(s) and how they internally processed and externally communicated model outliers and anomalous rainfall events overall. Interviews also explored forecasters’ perceptions of the relationship between these events and climate change and if those perceptions impacted the forecasts and messaging for the event. Using inductive qualitative analysis, components of sensemaking and decision-making conceptual frameworks were identified in the data and a simple forecast communication process model was created to illustrate the findings.