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Real-time early warning systems for shallow landslides are typically built upon real-time measurements and forecasts of rainfall and empirical correlations between past patterns of rainfall and landslide occurrence. Whereas these relationships describe whether certain combinations of rainfall and preexisting groundwater levels are of elevated risk of landslide triggering, not all combinations leading to landslide events necessarily have the same consequences in terms of landslide mobility (velocity and distal reach of the landslide). In this paper, the technique of geotechnical centrifuge modeling is used to quantitatively evaluate the hypothesis that the mobility of a landslide triggered under elevated antecedent groundwater conditions is higher than scenarios under drier antecedent conditions. Five identical slope models with a shallow depth to bedrock were subjected to different antecedent conditions ranging from zero groundwater flux to nearly saturated conditions prior to rainfall. The results from these scenarios show that higher antecedent groundwater conditions can result in landslides with velocities about three times higher and travel distances about eight times higher than low antecedent conditions due to static liquefaction of the soil at the base of the slope. [ABSTRACT FROM AUTHOR]