Impact-based forecasting In the news I UNIVERSITY OF OKLAHOMA RECEIVES US$1.4M GRANT FOR IMPACT-BASED WILDFIRE RESEARCH n February of this year, the Cooperative Institute for Severe and High-Impact Weather Research and Operations (CIWRO) at the University of Oklahoma received US$1.4m to conduct research into mitigating the impacts of wildfires across the country. CIWRO will use the grant to conduct two major studies: probabilistic fire weather guidance and fire weather observation analysis. Using 15 years of wildfire data, the probabilistic fire weather guidance project will identify a statistical relationship between the critical level of fire weather outlooks that are issued by the National Weather Service Storm Prediction Center (SPC) and fire spread rate, as well as the cost of fire suppression. “The resultant technology of this project will provide real-time guidance on anticipated cost and magnitude of fire suppression resources for a wildfire scenario as statistically related to the probabilistic critical level forecast of SPC fire weather outlooks,” says David Jahn, a research scientist at CIWRO and principal investigator on the project. “Such technology will be of real value to fire and emergency managers to anticipate the amount and cost of resources to address a specific wildfire event.” The fire weather observation analysis project aims to increase understanding and improve predictions of the structure, behavior and downstream impacts of both plume-and wind-driven wildfires in the USA, better characterize land surface conditions post-wildfire and enhance understanding of hydrological response to flash floods/debris flows post-wildfire. Using deployable radar and uncrewed aerial systems, scientists will collect unique observations of active wildfires and post-wildfire environments. This data will be used for detailed case analyses of wildfire-and post-wildfire-related events. It will also be used for the validation and development of the warn-on-forecast system for smoke, to improve short-term forecasts of up to three hours in high-impact fire weather events. Improved fire weather impact observations and forecasts are expected to aid decision making when determining where life and property impacts will be greatest and enable better mitigation efforts. Read more at: www.meteorological technology international.com Currently, NWS communicates risks via a product called the Impact-Based Warning. The warning takes the form of so-called ‘event tags’, which appear at the bottom of severe weather warnings issued by the weather service. In the case of a tornado warning, for example, the event tag will include tornado threat information such as the threat posed to life, business and property. Bieger notes that research from the WMO suggests that, “There may not be a one-size-fits-all way to conduct impact-based messaging. The point of this transition is to find ways to best meet the needs of specific populations, so different kinds of messaging systems may naturally result.” What influences a weather impact there were 61,410 wildfires on average annually in the USA ABOVE: From 2013 to 2022, the potential risks of different weather events. Among the risks associated with a medium-level impact for rain, for example, are injuries with danger to life, disruption to day-to-day routines and activities, and transportation routes and travel services affected. Weather tags at NWS Although NWS also uses color scales to depict weather risks and impacts, “There is no singular scale for all weather hazards,” according to Bieger. He explains that NWS is working with experts in societal, behavioral and economic sciences to develop “more clear and cohesive messaging of risks and impacts across a continuum of impact-based messaging”. There are many challenges to conveying the impact of a weather event, not least of which is the fact that weather is by no means the only variable influencing how a weather event affects a community. For example, the same volume of rainfall can have very different consequences depending on the conditions on the ground, notes Walsh. “If you have 30mm in a couple of hours, and it’s on completely dry ground at the start of the season, it might have no impact whatsoever,” he says. “But if it’s on saturated ground where you’ve had a winter’s worth of rain, that may generate a warning.” Another big influence on impacts are the demographics and the socioeconomics of the affected communities. To give a simple example, the elderly are usually much more at risk from extreme weather than young people. Also, notes Walsh, young people – specifically young men between the ages of 18 and 30 – are statistically “the most likely to not take any action off the back of a warning”. This brings us to another problem with impact-based warnings, which is the perception of risk and how it varies among different groups. “The perception of risks for a given weather event varies among the public based on a variety of external individual and socioeconomic factors including age, gender, education level, past experience and much more,” says Bieger. “Some events are more difficult to visually experience, such as excessive heat or cold, which in turn makes demonstrating impact challenging. “Moreover, some threats are discounted because they seem more controllable and less scary, even if they cause the most fatalities. Impact-based messaging is essential to bridge 28 • www.meteorologicaltechnologyinternational.com • April 2024