Forecasting: Uncertainty
Answer: What's Your Risk?


The tropical cyclone probability forecast assigns a probability of 14% to your location, with landfall expected in 72 hours. It takes 30 hours to evacuate your community. What should you be doing now?

  1. Nothing, the hurricane has an 86% chance of missing us.
  2. Call for an evacuation to begin in 42 hours.
  3. Begin contacting agency heads and elected officials to get them to start thinking about what they need to do if an evacuation is ordered in the next 2 days.
The correct answer is #3. If you chose the first answer, you are not taking into consideration the maximum probability for the 72-hour forecast period; 14% is about the highest it can be in this period. That means that, at least for now, the forecast says the hurricane is headed straight at you. The actions in answer 2 are premature at this stage, given forecast uncertainty. Answer 3 is the best choice because you're getting people who will need to react started on their preparations, but can wait to commit to further actions if future conditions and forecasts warrent.