Speaker Notes:

• This schematic shows several features associated with supercell thunderstorms. The yellow line illustrates the rotating updraft. The light blue line is the forward flank downdraft, which brings wind, rain and sometimes hail. The red line is what is called the “RFD” or rear flank downdraft. More about the RFD will be mentioned later.

• Sometimes there is a lowering of the rainfree cloud based with a supercell thunderstorms. This is called a wall cloud, and if a tornado forms, this is where that formation will occur. Note, that only a small number of wall clouds produce tornadoes.

• To the far right, you will notice a ‘point’ to the cloud where the illustration “direction of movement” is printed. This ‘point’ is referred to as the ‘anvil’. The anvil usually indicates which way the storm is moving.

• Also notice above the yellow updraft the ‘bubble’ on top of the storm. This is called an ‘overshooting top’, and is a good indicator that the storm may be severe. This overshooting top is caused by the momentum of the updraft. Remember, the stronger the updraft, the stronger the thunderstorm.