September 10th: What does peak hurricane season mean?

It is well understood that September 10th marks the peak of the hurricane season. But, what does this mean?

Officially, the Atlantic Hurricane Season runs from June 1st through November 30th, but statistically, September is the month that produces the most tropical storms and hurricanes.

The date, September 10th, is significant because it is the climatological peak of the season. Meaning that on this day, on average, you are most likely to have a tropical storm present in the Atlantic basin.

Tropical storms thrive when there is relatively low wind shear (i.e., change of wind speed and direction with height), high humidity and warm ocean temperatures. The sweet spot occurs when most of these ingredients are simultaneously present, that is, from late August through mid-October.

According to Phil Klotzbach, a hurricane research scientist at Colorado State University, about 75 percent of Atlantic seasons have had one or more named storms. Meanwhile, about 50 percent of seasons have had at least one hurricane active on September 10th.

Although it is more likely than not that a named storm is active in the Atlantic basin around September 10, this does not mean we are guaranteed to experience hurricane impacts on this day. Deadly hurricanes can happen at anytime during the hurricane season.

One example is Hurricane Audrey, which made landfall coincidentally near the Texas-Louisiana border as a Category 4 hurricane on June 27th, 1957. The storm brought 8 to 12 feet of storm surge that penetrated as far inland as 25 miles.

Rising waters were responsible for most of the 400-plus deaths from Audrey, and the cost to the United States was an estimated $1.4 billion (in today's dollars) worth of damage.

Another reason why it's not worth concentrating on just one single day of the year, or peak for that matter, is that peaks are relative to the data we look at.

Brian McNoldy, a senior researcher at the University of Miami, points out that there is not one single peak of hurricane season, but many different peaks or secondary peaks, depending on which years we look at and how active each of those periods is.

Our team of meteorologists at Weather & Radar will be watching the tropics closely throughout the season and will bring you prompt updates and forecasts.