Are You Guilty Of ‘Anchoring’ When Using Weather Forecasts?

Here in Georgia there is a major Senate runoff election on Tuesday. For the past week, I have been periodically checking the weather forecasts for December 6th. As a meteorologist, I know to evaluate the evolving forecast, but many people are guilty of “anchoring.” What is that, and are you guilty of it?

The formal term for anchoring is anchoring bias. There are several representations of the anchoring bias. The Decision Lab website describes it as, “a cognitive bias that causes us to rely too heavily on the first piece of information we are given about a topic.” This is something that I routinely observe with weather forecasts. We saw this recently with Hurricane Ian, and we routinely see it here in the South with snow forecasts.

People will look at the forecast 5 to 7 days out and then “anchor” to that very scenario even though weather systems are dynamic. The Decision Lab website goes on to say,”When we are setting plans or making estimates about something, we interpret newer information from the reference point of our anchor, instead of seeing it objectively.” That approach can often shape a bad decision or interpretation. For example, many people interpreted Hurricane Ian (2022) as likely to impact the Tampa Bay region, yet the Lee County area was in the cone of uncertainty and under storm surge warnings in evolving forecasts days ahead of landfall.

Simplypsychology.org describes anchoring bias as, “A faulty heuristic which occurs when you focus on one piece of information when making a decision or solving a problem.” However, the site does acknowledge that wrong final estimates or decisions are often anchored to initial values or information. Weather processes will always have uncertainty. That is why “percent chance of rain” and “hurricane cones of uncertainty” are utilized rather than specific information at an exact location.

From this point forward, try to adopt these best practices:

• Watch the evolving forecast if you have something planned several days to a week in advance. Do not “anchor” your plans on what you see a week ahead of time.
• If you are facing a rapidly evolving severe weather threat, review the situation before you go to bed or head out. Do not “anchor” in something you consumed earlier in the day.
• Always have a “night plan” for weather before you go to bed.
• Do not “wishcast” because the forecast you saw early on is consistent with what you are hoping for .