Breakdown: Why tropical activity usually peaks in late summer

Why tropical activity peaks in late summer

MEMPHIS, Tenn. (WMC) - While the Atlantic Hurricane seasonal officially began on June 1, we are now entering the “season within the season,” described by the National Oceanic and Atmospheric Administration.

This eight-week period is often called the most active and dangerous time for tropical cyclone activity.

Tropical Frequency
Tropical Frequency (Source: WMC Action News 5)

According to NOAA, from Mid-August to Mid-October, the activity spikes, accounting for 78 percent of the tropical storm days, 87 percent of the category 1 and 2 hurricane days and a whopping 96 percent of the major category 3, 4 or 5 hurricane days.

The reason why the activity begins to peak deep into summer is the environment that these potential tropical cyclones tend to encounter. Wind factors, along with temperature and moisture factors, all play a role in tropical storm formation.

Wind shear can tear disturbances apart before they strengthen, which gradually fades latter in the season, reaching a minimum in mid to late August. The lack of shear combines with the increase in air temperature, water temperature and building moisture in the tropics.

All components are in sync from mid-August to early October, meaning when African tropical waves form, they can easily strengthen. The statistical peak of hurricane season is September 10.

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