Nerd out: RPG weather.

I am going to write a "iphone" web app.  it will actually run for any smartphone or tablet, but i have an iphone so that is where it will be tested.  what I am going to write is a "Game weather generator".  I have the following idea down.   Select a world city that is closest to what your "world location" is like as a random seed starting point of weather or set your own starting point..  all I care about is the barometric pressure and temperature.   From those two I will generate the weather and wind as well as temperature.   a random number generator will generate from -1 to +1 this will move a scale of  -5 to +5 and each 1/2 hour passed the barometer will change that amount.  As the barometer get's lower the weather will get worse, as it get higher it get's better.  Now based on the barometer and another random number slider the temperature will also change.  if the barometer is high then the temperature will  be encouraged to trend upwards but not forced. two successive negative will move it negative.  also temperature will follow a typical day/night curve with the 2 hour delay like we see in real life.

Wind I need to think about. to do it right I need to simulate fronts. so if it was trending up but is now trending down  the wind will be out of the  prevailing wind direction.  the other way will have the winds reversed. with some north-south randomness.  

it's a start,  hopefully I can find some better weather simulation rules to base my code off of.


Now the GM can select, "4 hours have passed" and now they will get the new current conditions.