We need to change how we look at hurricane season.

Today is the start of the 2017 Atlantic hurricane season. The peak of the season climatologically is Sept 10th.  I have already seen headlines like this, and they make me cringe!

“The 2017 Hurricane Season is predicted to be bad”

Why because there might be an above average number of storms? Well the Atlantic is a huge ocean and the number of storms might increase our chances of getting hit, but not necessarily. It only takes one storm for it to be bad. We really don’t care about the number of storms but more if they will impact us. Seasonal hurricane forecast of the number of storms doesn’t do that. That is why I feel like we focus too much on Hurricane Seasonal Forecasts of named storms. For a long time, I have not been a fan of all the mass exposure the seasonal forecasts get. The number of named storms is just a horrible metric of seasonal severity and intensity. The general public does not care how many storms there are in the entire Atlantic they simply care whether or not they will affect them. So 15-20 “fish” storms are irrelevant to the public if none of them impact the U.S. Especially when all the news coverage seems to be a “bad” hurricane season based on the high number of storms forecasted. The problems arise when people think something is going to happen and it doesn’t they lose their sense of being prepared. 

There are countless examples of seasons where we get few storms, but 1-2 are impactful. Case in point was in 1992  when Hurricane Andrew was the 2nd most devastating storm to hit the U.S. It was just the 1st of only 6 named storms that entire season.

at1992

Then in 2010 we had 19 named storms which is the 3rd most active on record in the Atlantic. Though that year just 1 weak tropical storm made a U.S. landfall that season.

at2010

So to the public which season was worse? Andrew with a devastating impact and only 6 storms or 2010 with 19 storms and no impacts? I think the answer is pretty simple, but we continue to focus on the numbers of storms. The build up of the seasonal forecasts by the media further highlights the problems. Often missing in the coverage is the perspective on how big the Atlantic is and how the number of storms doesn’t equal intensity or severity of impacts on the U.S. Also missing is communicating the unknowns of seasonal forecasting and how they are still not proven accurate enough to gauge how hurricanes could or will impact you.

Inflation of Named Storm Numbers:

Another issue that is arising is the inflation of the number of named storms. It’s kind of a running joke that we seem to be naming any thunderstorm that swirls for a few minutes in the Atlantic. This isn’t some grand conspiracy by the government to meet their seasonal forecasts for named storms. It’s a simple matter of us having better tools to diagnose tropical systems then we have ever had before. With the modern satellite observations & coverage tools like Scatterometers along with GPS Dropsondes, Doppler Radar, Hurricane Drones, etc. We seem to have an ever-growing bevy of tools to name a storm system. We had a similar thing happen with tornadoes with the advancement in Doppler radar technology. The number of low-end tornadoes being reported to have increased tremendously. The Storm Prediction Center wisely knew there was an observational bias now and adjusts their numbers for this inflation. I think it’s time for the NHC (National Hurricane Center) to maybe think about something similar. I

I went back and looked at the 2005-2015 hurricane seasons and about 24% of all the storms that have formed in the Atlantic over that time period have had a minimum central pressure at or above 1000 mb. Remember this is the lowest pressure in the life span of the storm so many times the pressure was actually much higher.

This isn’t meant to be disparaging of the naming of any of these storms. It just seems logical that we are naming more weak storms than we have in the past due to our advancements in both observations and meteorological understanding of tropical meteorology.

Better Metric:

I’ve always been a fan of ACE or Accumulated Cyclone Energy to gauge how a season is going. The ACE of a season is calculated by summing the squares of the estimated maximum sustained velocity of every active tropical storm (wind speed 35 knots (65 km/h) or higher), at six-hour intervals. (Yeah Math) It’s really a measure of how strong each storm is and how long it sticks around. Here’s a look at how ACE matches up over the past several seasons globally?

( Graphic via Dr. Ryan Maue)

More focus on impacts and not labels:

As we saw last year with Matthew and in the past with Sandy people get caught up in what we call things and if it has a name. When in reality the impact of a storm are far more important to what we call it or it’s named. We already have this issue with wind damage where we argue over the tornado or straight line winds when all that matters is the wind speed and damage done. Like with Matthew a storm that technically never made landfall in the Carolinas. Yet it caused $1.5 Billion dollars in damage and killed 26 people in North Carolina alone. We should spend less time on the naming of a storm or it’s exact path and more on it’s impacts. The impacts to you and I are really the only way we can measure whether a hurricane season was bad or good. That fact isn’t known until the season is over not before.

  • emlit

    “(Yeah Math)”

    …had me in stitches. You go, weatherman.

  • Mr_McBud

    If a weatherman farts in Charlotte, could it cause a hurricane somewhere else?

  • tv22

    Glad you pointed out the issue with the number of storms. Up until relatively recently, storms were only noted by weather reports from ships in the area. Storms could have formed without anyone noticing. Part of the problem is everyone wants to read something into the weather every time it varies from an average. As we know, weather doesn’t work that way!