Why Nepal's rare, deadly flood struck without warning

Nepal recently experienced a devastating flash flood that left thousands missing and hundreds dead, striking unexpectedly with little warning. This tragic event highlights significant shortcomings in the existing warning systems, which typically focus on extreme rain and river monitoring but fail to predict sudden glacier-driven floods occurring even under clear skies. Such "blue-sky floods" are not just a concern for Nepal but also pose risks in parts of the U.S., especially in Alaska and the Pacific Northwest, underscoring the need for improved, comprehensive alert systems.