Are you guilty of “anchoring” when using weather forecasts?

Here in Georgia, there is a Senate runoff on Tuesday. For the past week, I have periodically consulted the weather forecast for December 6. As a meteorologist, I know how to assess the evolution of forecasts, but many people are guilty of “anchoring.” What is it, and are you guilty of it?

The formal term for anchoring is anchoring bias. There are several representations of anchoring bias. The decision lab website describes it as “a cognitive bias that causes us to rely too much on the first piece of information we receive about a subject”. This is something that I observe regularly with the weather forecast. We saw it recently with Hurricane Ian, and we see it regularly here in the south with snow forecasts.

People will look at the forecast 5-7 days from now and then “anchor” themselves to that scenario even though the weather systems are dynamic. Decision Lab’s website goes on to say, “When we make plans or make estimates about something, we are interpreting more recent information from our anchor’s point of reference, instead of seeing it objectively.” This approach can often shape a wrong decision or misinterpretation. For example, many people interpreted Hurricane Ian (2022) as likely to impact the Tampa Bay area, but the Lee County area was in the cone of uncertainty and below storm surge warnings in the changing forecast days before landing.

Simplypsychology.org describes anchoring bias as “a faulty heuristic that occurs when you focus on a single piece of information when making a decision or solving a problem”. However, the site recognizes that erroneous final estimates or decisions are often rooted in initial values ​​or information. Weather processes will always be uncertain. This is why “percent chance of rain” and “hurricane uncertainty cones” are used rather than location-specific information.

From now on, try adopting these best practices:

• Keep an eye on how the forecast is changing if you have something planned several days to a week in advance. Don’t “anchor” your plans on what you see a week in advance.
• If you face a rapidly evolving threat of severe weather, assess the situation before going to bed or going out. Don’t “anchor” yourself to something you consumed earlier in the day.
• Always have a “night plan” for the weather before you go to bed.
• Don’t “wishcast” because the predictions you saw at the start are what you’re hoping for.