Systems and methods include a method used in drilling wells. A three-dimensional (3D) uncertainty cube is generated for a subsurface geological structure containing a well target for drilling operations of a well. The 3D uncertainty cube defines an uncertainty of a geological position relative to a 3D structural model. The 3D uncertainty cube is dynamically updated in real time while drilling the well, including parameterizing the 3D uncertainty cube for a distance ahead of a drill bit. A probability that the well target will be hit is determined using the 3D uncertainty cube. The drilling operations of the well are dynamically re-planned and re-steered based on the updated 3D uncertainty cube, including updating a direction of the drilling operations of the well using the 3D uncertainty cube and the probability. Drilling and acquiring new information are continued to iteratively continue dynamic updates and continued drilling.