Are Hyperactive Seasons Historically Backloaded?

[Spacecoast]

Plotting the historical distribution of Hurricanes:
(June =4%, July =6%, August = 26%, Sept = 39%, Oct =20%, Nov = 5%)...

1991-2020 Average number of Hurricanes: 7.2 (black)
2022 Forecasted number of Hurricanes: 10 (Red)


Plotting distribution of 'hyperactive' years:
(1969, 1995, 1996, 1998,1999, 2003, 2004, 2005, 2010, 2017, & 2020)

Note that many of these years are indeed very back-loaded (1969, 2005, 2010, 2020) with very active late seasons.
Some follow the historical distribution (1995, 2004).
The Average distribution of these hyper seasons (Red)

Comparing the 1991-2020 Average season using historical distribution (black),
2022 Forecast using historical distribution (green), and
the ave. distribution of hyper seasons (red)....

draw your own conclusions, but it appears the hyper seasons tend to be back-loaded, (but not all back-loaded seasons are hyper).

The distribution of Hurricanes (front-loaded, normal, or back-loaded) are relatively independent of activity levels, but (on average), hyper seasons appear more active than the baseline for each of the six months, especially October.

[HoustonFrog]

Interesting information, thanks for compiling.

[Spacecoast]

Interesting information, thanks for compiling.

Thanks. I wasn't happy with the monthly resolution above, so I decided to parse /process HURRDAT2 data to get daily / weekly resolution...

Here is a daily plot of total number of hurricanes by day of formation (1950-2021):

Sept 11th & Sept 25th both had eleven Hurricanes form since 1950
Sept 1st had ten Hurricanes form since 1950
Sept 2, 5, 9, & 14 each had nine Hurricanes form since 1950


Here is a Weekly Historical % distribution (1950-2021):

This shows that historically, 11.8% of each season's Hurricanes form on the week ending 9/13.
In a typical year, 10.5% of the seasons' total would have formed by the week ending Aug 2nd.

Plotting Distribution Hurricanes per Week (higher resolution than the monthly above):