| To understand stream drying controls, we observed drying patterns using a dense spatiotemporal network of flow sensors interspersed between baseflow monitoring locations in two headwater streams at the Reynolds Creek Critical Zone Observatory in Idaho.Our findings include very fine-scale variations in drying, discontinuous surface flows, and locally variable baseflow fluxes. These indicate: 1) wet-dry diel cycles in streamflowprecede seasonal stream drying, 2) the timing of stream drying varies with controls on evapotranspirationwhen all other conditions for stream drying are met, and 3) a stable baseflow flux enables surface water to persist even when precipitation is low. Short lags between peak temperature and dryingsuggests local effects outweigh network effects.Future studies should 1) continuously monitor evapotranspiration in riparian andhillslopelocations, and 2)addspatially distributed hydraulic conductivity and geophysical imagingto improve stream drying predictions. Keywords: stream drying, intermittent, diel cycling, evapotranspiration, baseflow, subsurface characteristics, headwaters, topographic metrics, Reynolds Creek, Critical Zone Observatory, Idaho |