We often cannot avoid value uncertainties when curating raw data to obtain a final visualization image. Although numerous studies maintain the importance of uncertainty visualization, there lack a standard means of depicting the information, especially in 3D flow visualization tasks. We introduce a novel glyph design referred to as the disk-tailed arrow which shows the trends and uncertainties in 3D vector fields concisely. The proposed design includes a glyph shape and modeling strategies which map statistical information to visual cues. Our scheme is devised so that the user can perceive 3D uncertainty information effectively. We also present a case study of the application of the proposed glyph to an actual flow dataset as an assessment.