https://www.sciencedaily.com/releases/2022/08/220809141142.htm

A new study revisits the deadly event with the goal of testing how hyper-local modeling can improve forecast accuracy for mountain events. The runners ran into trouble because hourly weather forecasts for the race underestimated the storm. The steep mountain slopes had highly localized effects on wind, precipitation and temperature at too small a scale for the weather forecasts for the event, according to the new study, which is published in the AGU journal JGR Atmospheres.

Hourly forecasts for the 2021 race were based on relatively large-scale atmospheric processes, with models running at a resolution of three kilometers -- sufficient for most regional predictions, but too coarse to capture the "hyper-local" weather like the storm that struck the course, says Haile Xue, a climate scientist at China's CMA Earth System Modeling and Prediction Centre and lead author of the new study. Even though a wind and cold temperature advisory had been issued the night before, it lacked the resolution required to pinpoint the danger zones on the course.