Staring at a hailstone helps to determine various characteristics, such as shape or size. However, from the physics point of view, one of the most important characteristic is the type of growth. Each of the stone’ elements (nucleus, lobes, rings) is conductive to explaining the environmental behaviour of its formation and development stages. The thermodynamic variables derived from the upper-air soundings or the numerical weather prediction simulations can help us understand the differences between the different growth modes. In this way, the hail type has been analyzed according to its shape and size. The study has comprised 151 hailstorms that occurred in Catalonia (NE of the Iberian Peninsula) between 2017 and 2020. We have characterized the events according to different properties. The size of the stones (small, large and, huge), the shape (embryo, spherical, and irregular), and, the season of occurrence (spring, summer, and autumn) are the selected characterizing elements. Maximum vertical updraft velocity, vertical wind shear, and precipitable water content are the variables that explain better the behaviour of each category. •Knowing the hail shape in the future hours facilitates improving the nowcasting of hailstone properties.•The research has consisted of combining ground-based observations with simulated thermodynamic atmospheric profiles.•The analysis has been made dividing the hail dataset into different categories, based on season, size, height, and shape.•Shape and size present a good correlation, but no significant trend was found regarding to the stone’s height collection.•Combining thermodynamic parameters (max. estimated vertical velocity and precipitable water content), improves nowcasting.