Nov 19, 2026: BC Branch: Probable Maximum Precipitation and Flood Estimation Under Climate Change
Date: Thursday, November 19, 2026 12PM-1PM (PCT)
Topic: Probable Maximum Precipitation and Flood Estimation Under Climate Change
Speakers: Elise Legarth
Description:
Probable maximum precipitation (PMP) and probable maximum flood (PMF) estimates are the foundation of dam safety design. Traditional estimates assume a stationary climate and an upper bound on precipitation, but it is increasingly important to understand how the PMF may change as the climate warms. This talk gives an overview of current science on climate change and extreme precipitation and floods, reviews how PMP and PMF are estimated today, and examines where these methods may fall short under future climates. Research will be presented that applies CMIP6 derived pseudo-global warming perturbations to a numerical weather prediction model to assess the impacts of climate change on atmospheric rivers and the PMP, before assessing how the resulting PMF for the Alouette watershed in British Columbia would change. The findings show that scaling precipitation by the Clausius–Clapeyron relationship or by CMIP6 projections can either underestimate or overestimate the PMF, depending on storm duration. The talk will give engineers, hydrologists, and dam owners a clearer picture of the uncertainties in current practice, along with practical considerations for developing PMF estimates in a future climate.
