Fertilizer application is essential for maintaining agricultural productivity, but in the Midwestern US, extensive subsurface tile drainage expedites nutrient losses from fields to adjacent waterways, especially during storms when fields are fallow. The planting of winter cover crops (CC) can prevent dissolved N and P losses from fields, but their impact on storm-driven losses of total N and P is understudied. We hypothesized that nutrient loss reductions due to CC would be similar for nitrate (NO3--N) and total nitrogen (TN), because NO3--N dominates TN. In contrast, CC-driven reductions in total P (TP) will be greater than for soluble relative phosphorus (SRP) because TP loads are dominated by particles. We used a paired field design in two agricultural watersheds in Indiana, the Fleming Ditch (FFD) and the Shatto Ditch (SDW), using autosamplers on tile drains for fields with and without CC, collecting samples for multiple storms (SDW=8, FFD=7). In FFD, hourly NO3--N yields from the CC field were 56% lower than for NoCC (CC=679 vs. NoCC=1546 mgN ha-1hr-1), while in SDW, hourly yields were 82% lower with CC (CC=570 vs. NoCC=3290 mgN ha-1 hr-1). Similarly, TN yields with CC were 85% lower in SDW (CC=626 vs. NoCC=4239 vs. mgN ha-1 hr-1), confirming that the majority of TN was lost as NO3--N. In FFD, CC planting also reduced SRP yields by 31% (CC=6.7 vs. NoCC=9.8 mgP ha-1 hr-1), whereas SRP yields were 96% lower with CC in SDW (CC=0.6 vs. NoCC=19 mgP ha-1 hr-1). Contrary to our hypothesis, reductions in TP yields in SDW mirrored SRP, and were 98% lower with CC (CC=1.1 vs. NoCC=61 mgP ha-1 hr-1). Overall, CC reduce both dissolved and total N and P yields during storms, reinforcing their value as a strategy for preventing nutrient losses to streams in the agricultural Midwest.