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What is the climatological peak of hurricane season?

BOSTON — September 10 is the climatological peak of hurricane season.

More tropical storms have occurred on this date than any other when we take a look at the 100-year average.

According to Phil Klotzbach (Hurricane Researcher at Colorado State University), this is also a day that, about 75% of the time, at least 1 named storm is swirling in the Atlantic.

About half of the time we have at least one active hurricane.

But why is today the statistical ‘peak’ of the season?

The answer lies in the ingredients.

Hurricanes need warm water and low wind shear (shear being an increase in wind speed with height) to form and strengthen. This time of the year, all of the sun’s energy from the summer has warmed the water well into the 80s.  Wind is driven by differences in temperature that create differences in pressure, and without this sharp temperature difference (thanks to cold air being bottled up in the Arctic and hot, humid air ruling the tropical Atlantic), we have a recipe for tropical cyclone development.

New Englanders should continue to keep an eye on the tropics right through October.

Average hurricane tracks run from the Caribbean right up through the water just off the eastern US coast.  This is due to dips, or troughs, in the winds that steer hurricanes.  As these winds orient more south to north, there’s an increased chance to bring tropical systems closer to our coastline.

Now, it is unlikely that these systems actually make landfall in MA as history shows us. But even a glancing blow can bring damaging winds, storm surge, and flooding rain.

Many of us remember Hurricane Sandy that came ashore in New Jersey on October 29, 2012.  That storm brought 70 mph gusts and a 5-foot surge to MA.