Deep learning (DL) models currently represent the state-of-the-art in hydrologic prediction (Nearing et al., 2021;Shen et al., 2021), as evidenced by their unmatched accuracy in predicting streamflow (Liu et al., 2020), soil moisture (Li et al., 2021), evapotranspiration (Ahmed et al., 2021), stream temperature (Rahmani et al., 2021, and water quality indicators (Aldhyani et al., 2020;Zhi et al., 2021). For streamflow prediction, long short-term msemory networks (LSTMs, Hochreiter & Schmidhuber, 1997) have proven particularly effective due to their strong inductive bias toward storing information over time (Hoedt et al., 2021). This property is well suited for capturing hydrologic dynamics driven by multi-scale memory effects within a watershed, such as the persistence and release of water from soil moisture and snowpack. LSTMs trained across a large number of watersheds have been shown to outperform process-based hydrologic models by a substantial margin (Kratzert et al., 2018), even at hourly timescales (Gauch, Kratzert, et al., 2021) and for watersheds treated as unseen by the LSTM (Kratzert, Klotz, Herrnegger, et al., 2019). Given their high degree of performance, LSTMs are being considered for a range of hydrologic applications, including forecasting (Cheng et al., 2020;Sharma et al., 2021), streamflow estimation