- Talk to Debbie.
- Go outside to the storm-chasing truck.
- Drive to either the nearest storm cloud or the windmill.
- Activate the Doppler machine.
- Open the side panel on the truck.
- Flip 3 switches at a time in order to activate the radar (when all the lights are blue).
- Numbering the switches from left to right, the top row being 1-6 and the bottom being 7-11, flip the switches in the following order:
- 1, 4, 5. Press the button on the right.
- 7, 9, 11. Press the button on the right.
- 2, 3, 11. Press the button on the right.
- 3, 8, 11. Press the button on the right.
- The scanner will work briefly, then dissolve into flames.
- Zoom into and open the gray container (next to the red cooler) in the middle of the truck.
- Arrange the cables and plugs properly, then press the button located at the bottom.
- See screenshot for solution.
- Debbie tells you to return to base.
- Go to the desk in Scott's Office.
- Notice a piece of paper sticking out of one of the drawers.
- Open the drawer with the key and read the note.
- Go to the cellar.
- Zoom into the piece of paper under the sink that reads Storm Weather Symbols.
- Check out 63: moderate rain, continuous.
- The symbol is made up of 3 black dots.
- See 89: light hail no thunder.
- The symbol shows 2 triangles.
- Finally, look at 99: severe thunderstorm with hail.
- The symbol appears to be a B with an open triangle on top.
- Check the Open Surface Charts binder on the lower shelf behind Frosty's desk.
- Look for the 3 storm weather symbols:
- 45+ dewpoint and continuous moderate rain.
- 85 degrees + with either light hail.
- 85 degrees + no thunder or severe thunderstorm with hail.
- They are found on:
- March 3, 8, 18, 21 and 26.
- April 3, 6, 10, 23, 29.
- May 6 and 12.
- Return to Scott's office.
- Check the wall calendar near his desk.
- Start at March.
- Use your own computer and type in the letters and numbers on the dates taken from the surface chart.
- The solution is: WM9A, GV2C, SH4A.
- Once typed in correctly, they will appear on a piece of paper.
- Click it to add it to your inventory.
- Return to the cellar and access the laptop.
- Check the gallery until you find the photos with the number/letter combinations listed above.
- They all have one thing in common. They're pictures of the windmill.
- Talk to Debbie.
- Drive to the windmill and see Scott there.
- After talking with Scott, Nancy blacks out.
- Nancy returns to consciousness and hears Debbie on the radio.
- Get in the car to talk to Debbie.
- Use the GPS to drive to the Grange.
- Once at the Grange, proceed to the storm shelter.
- Use the keys from your inventory on the lock to open the first shelter door.
- Enter the shelter.
- The second set of doors is locked.
- Click on the panel located to the right of the door to open it.
- Select the 4th key from the left in the top row to unlock the doors.
- Wait in the shelter until the storm has passed.
- Exit the shelter.
- Follow the storm truck: the arrow on your map shows you where it is.
- Be sure to avoid debris and the raging tornado!
- Follow the truck until it eventually crashes at the springhouse.
- Pick up the crowbar lying on the ground and use it to pry the boards off the door, then enter the shelter.
- Congratulations, you've finished Nancy Drew: Trail of the Twister!