Sonde Balloon Landing Probability Analysis

I need a statistician to calculate probabilities for Sonde Balloon landings in an area of the UK. So I need you to tell me how you will go about this. I need it done by Monday. There are 3 actual balloons we need calculated, but they do a number of interesting things... (Budget: $30 - $250 USD, Jobs: Statistical Analysis, Statistical Modeling, Statistics)