Raw GFS data interpolation - calculating precipitation at a specific altitude?

Question

The GFS model gives 'total precipitation' for a grid cell (I am assuming that this is the average value for across the cell, rather than for a given point within the cell). This 'total precipitation' is for ground level (I am assuming that ground level is the average ground elevation across the cell, rather than the ground level of a given point within the cell). The model also gives Relative Humidity and Temperature for a grid cell and these values are given at a number of set altitudes (I am assuming that the value is an average value across the horizontal area of the cell).

The 'total precipitation' value is give only for ground level. I'd like to get a 'total precipitation' value for a certain altitude within the cell. Can I interpolate the data using 'height' which I have, the 'temperature value' and the 'relative humidity' values that the model gives? If so how can combine these to calculate precipitation?

Also are my above assumptions correct?

Many thanks in advance

Answer 1

I actually think the model output values are values at the grid point...and not averages of the cell...but I could be wrong.  

I'm not sure why you would want to compute total precipitation at some location above ground level though, and I don't even think it is realistic.  If you think about it, what constitutes precipitation above ground level?  If you're 5000ft above ground level, for instance, you can have precipitation moving in all directions due to turbulent air flow.  I suppose you could define precipitation as water with downward trajectory, but I can't even imagine how you would begin to quantify that, and I think you would need more than temperature and RH to do so.  

May I also suggest trying a more meterology-specific website for these questions?  There are some knowledgeable people here...but you probably would reach a greater number of meteorologists with technical model experience by posting on a weather specific message board.  I personally use http://www.easternuswx.com .