High-latitude watersheds are experiencing rapid warming, resulting in changes to permafrost extent, seasonal thaw regimes, hydrological connectivity, and precipitation characteristics. In permafrost catchments, frozen ground restricts infiltration and percolation of water, confining flow paths to the shallow subsurface, promoting rapid runoff responses. As thaw progresses, deeper more heterogeneous flow paths develop, altering storage-discharge relationships and the efficiency of runoff generation. Despite these well-established concepts, event scale hydrological response in headwater catchments remains poorly constrained across gradients of permafrost extent. This study examines spatiotemporal controls on rainfall-runoff response across seven headwater catchments in NWT and Yukon, Canada, spanning a gradient from mostly permafrost underlain to largely permafrost free conditions. Using high frequency hydrometric data from 2001-2025, individual streamflow events were extracted and characterized using power law recession analysis to describe catchment sensitivity of discharge to changes in storage. Event metrics including runoff ratio, antecedent wetness, rainfall intensity, and concentration-discharge indices were used to evaluate controls on runoff generation across space and time. Results indicate that catchments with less permafrost exhibit more non-linear recession, consistent with greater subsurface storage and hydraulic connectivity. Random Forest analysis identifies slope, day of year and permafrost region as strong predictors of recession behaviour rather than individual storm properties. This demonstrates that the evolving subsurface connectivity and catchment structure exert stronger controls on event-to-event hydrological response to events in permafrost influenced headwater systems. Our results provide insight into how runoff generation and storage dynamics may reorganize as permafrost continues to thaw under a warming climate.