Offshore Atlantic hurricane-start wind-loss rates showed no clear era change after wind and latitude weighting in 1982-2023

We tested whether 24-hour wind losses of at least 30 kt became more frequent in offshore North Atlantic hurricane-start windows. We used fixed IBTrACS v04r01 data and compared 1982-2002 with 2003-2023. All five six-hour fixes had tropical status, latitude from 0 to 35 N and center distance to land of at least 200 km. There were 821 early and 1,059 late windows from 72 and 90 storms. The observed loss rate rose from 2.68% to 5.29%. With common starting-wind and latitude weights, the rates were 3.21% and 5.01%. The weighted change was +1.80 percentage points, with a 95% three-season block interval of -2.47 to +4.79 points. All eight weighted checks had intervals that included zero. Some raw checks gave positive intervals, so the result depends on the comparison used. These data do not resolve an era change in the weighted conditional rate. They also do not show equal rates. Overlapping windows, sparse strong-storm groups, selected surviving tropical records and changes in wind estimates limit inference. No ocean or atmospheric fields were used. The package gives source rows, hashes, code, block draws, a figure and an independent count audit.

North Atlantic · rapid weakening · IBTrACS · initial intensity · standardization · block bootstrap · null result