Lewis Fry Richardson ( ) A famous British meteorologist Today we will explore his idea. The weather can be forecast by solving equations which represent the atmosphere.

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We will predict the temperature at each grid-point 1.Collect data about winds and temperatures at our grid-point and to the north and west. 2.Fill in information on computing form. 3.Complete calculation. 4.Communicate prediction to other grid- points and forecast central (me). 5.Repeat 4 times. Each calculation will predict one hour ahead, by the end of our forecast we will predict temperatures in 4 hours.

Computer Models Logical operators –IF TIME EQ 22 THEN GOTOBED=1 Loops –FOR TIMESTEP=1,4 DO PRINT,Timestep:,TIMESTEP Mathematical equations: In computer models there are a huge number of these IFs and DOs and equations describing different processes that all interact with each other over millions of grid boxes each time-step