Heavy rainfall from tropical cyclone remnants in mountainous regions can cause mountain streams to overflow, overwhelm flood-control infrastructure, wash trees and other debris downstream, and prompt evacuations and emergency protective measures such as sandbagging.
October 11, 2025
high
temporal
Typical hydrologic and emergency-response outcomes when tropical moisture impacts mountainous terrain.
Moisture from tropical cyclone remnants can increase precipitation and, at high elevations with cold temperatures, can contribute to snowfall.
October 11, 2025
high
temporal
Interaction of tropical moisture with seasonal or elevation-driven cold air leading to mixed precipitation types.