How to replace the missing temporal data of the ocean tidal levels for hydrodynamic modeling of an estuary?

I am modeling the hydrodynamics of an estuary with a 3D model, to use it for sediment transport and quality purposes. The model extends from the inland river till the ocean, and the total length of the model is approximately 500 km. I have to run a simulation for 1 year period but one of the boundary conditions of levels in the ocean is missing 15 days of data. There is another station with values in those 15 days at an approximate distance of 100 km (inside the model), and there is overlap of information outside of that time period in order to study them together or correlate them. Would it be possible to estimate the 15 days missing values with the tidal values of the other station? Both are oceanic stations. Could you please, suggest me which would be the best procedure to follow?