CONTENT UPDATE to Page 186

Primo weather blogger Dr. Jeff Masters points out that I raise the expectation in the first two sentences of “Get Rid of the 5-Day Cone”, that I’m going to cite some research to support the statement, “The 5-Day Cone does more harm than good”. In my mind I was stating the obvious, given my experience in the hurricane zone talking to people and trying to understand why they felt over- or under-threatened when the cone was covering their town or aiming at their area. But, he’s right, the statement is misleading and needs more explanation.

Let me make try to my point clearer. I think the “cone of death”, as a general concept, has evolved into the best graphical awareness and preparedness device we have. A properly constituted 3-Day cone with clear labeling and without the insidious line down the middle is an excellent tool to communicate which areas have a substantial risk and expectation of being affected by a hurricane. (See the update to page 165.) If this tool were refined and standardized it would go a long way toward improving the understanding of the general public as to who is at risk and who needs to prepare, in my opinion.

The 5-Day cone, however, does not fill that role for 99% of the population. If the 5-Day cone is aiming at you, or even covers your city, so what? It’s hurricane season. Big news! For most people, it doesn’t mean prepare or even get ready to prepare. Given the state of modern hurricane forecasting science, the area covered by the 4 and 5-Day section of the 5-Day cone is so big that it’s not meaningful. The “warning” the 5-Day graphic delivers is most often false, so it weakens the credibility of the cone as a risk communications tool. Worse, it dilutes the potentially important function of the 3-Day cone to spur community preparation.

The folks at the National Hurricane Center would likely say that the issuance of a hurricane watch or warning should be the triggering mechanism for preparation. But, preparation is a process, and it begins with a community or an individual understanding the threat. First comes the mental process of evaluating risk, and it needs to start before a watch or warning is issued. In today’s system, the cone starts that process, and, in my opinion, it would work well if the 5-Day cone (and the generally poor interpretation of it by television weathercasters) didn’t dilute the narrow and easy-to-communicate rule that being “in the cone” means you are at risk and need to prepare.

Emergency managers I’ve talked to want the 5-Day alert for their internal preparation systems. The Navy also needs advance notice of a potential storm so they can position their fleet. But that’s no reason to screw up the public communications system to satisfy these needs.

As I say in the book, in my opinion the answer is using the “risk area” system. When a hurricane may threaten the coast, issue a Risk Area Alert. But, do it only when there is a substantial threat. The current 5-Day cone that covers your state for the possibility of a major hurricane is the same one that is used if the threat is from a tropical storm or depression. It’s no wonder a majority of the public says they didn’t understand their risk in survey after survey done after hurricane landfalls.