C21F -0902: Can a Hydrometeorological Warning System Be Used to Characterize Glacial Lake Outburst Flood Risk?

Glacial lake outburst floods (GLOFs) pose significant hazards to downstream communities and infrastructure, necessitating effective early warning systems. Warming global temperatures have led to widespread glacial retreat, increasing the size and number of glacial lakes worldwide. In situ measurements supporting high-resolution glacio-hydrologic models can help to meet this need, but their cost, the large number of glacial lakes, and the remote terrain where GLOFs occur ensure that many glacial lakes will not be monitored. This study explores the ability of an existing hydrometeorological warning system, the Flash Flood Guidance System (FFGS), to characterize the risk of GLOF occurrence, in combination with other available data sources. While the FFGS was not designed to predict GLOFs, it provides forecasters with ready access to relevant information and has extensive coverage in areas where they commonly occur, such as High Mountain Asia. We utilize inventories of glacial lakes and historical GLOF occurrences and extract FFGS hydrometeorological outputs and satellite-based remote sensing products at these locations to understand the prevailing hydrometeorological conditions leading up to these events, and develop a statistical characterization of GLOF risk. This case study points to a promising, low-cost means to give forecasters a better indication of the threats posed by GLOFs, particularly in regions with minimal existing capacity to forecast these events.