Activate the following cheats by entering the corresponding codes during game play:

CHEAT FUNCTION - CHEAT CODE
Snow or rain - SHIFT + CTRL + Alt + S
Start Snowing - SHIFT + Q
Stop Snowing - CTRL + Q
Rain - SHIFT + CTRL + R
Toggle precipitation - SHIFT + CTRL + P
More injuries - SHIFT + CTRL + I
Make everyone fall - SHIFT + CTRL + F
Free money - CTRL + SHIFT + C + A + T
More money - CTRL + SHIFT + 4
Toggle build rate - SHIFT + CTRL + W
Avalanche - SHIFT + CTRL + X
All buildings available - SHIFT + C + A + T
Toggle menu options - CTRL + K
Smoother mountain - CTRL + SHIFT + S
Fast frame rate - CTRL + W
Slow frame rate - CTRL + Y
Change power range to 99999 - CTRL + SHIFT + K

This code overrides the requirement of having an advanced ski school before you can have a ski jump. However, you still must have enough money. Start the game with the unlock command line parameter.