Unveiling WARIS code, a parallel and multi-purpose FDM framework. WARIS is an in-house multi-purpose framework focused on solving scientific problems using Finite Difference Methods as numerical scheme. Its framework was designed from scratch to solve in a parallel and efficient way Earth Science and Computational Fluid Dynamic problems on a wide variety of architectures. WARIS uses structured meshes to discretize the problem domains, as these are better suited for optimization in accelerator-based architectures. To succeed in such challenge, WARIS framework was initially designed to be modular in order to ease development cycles, portability, reusability and future extensions of the framework. In order to assess its performance, a code that solves the vectorial Advection-Diffusion-Sedimentation equation has been ported to the WARIS framework. This problem appears in many geophysical applications, including atmospheric transport of passive substances. As an application example, we focus on atmospheric dispersion of volcanic ash, a case in which operational code performance is critical given the threat posed by this substance on aircraft engines. Preliminary results are very promising, performance has been improved by $8.2 imes$ with respect to the baseline code using a realistic case. This opens new perspectives for operational setups, including efficient ensemble forecast.