wrote:

On Friday, July 24, 2020 at 10:39:51 AM UTC+1, Norman Lynagh wrote:
Here is one example of the sort of problems that I encounter:

If you have 20 years of hourly wind data from what is normally a
relatively benign location, but the data includes 6 hours of high
winds resulting from the passage of a hurricane, how do you
extrapolate the distribution to predict the once in 50-year wind
event? The short answer is that it is impossible.

The problem is that the winds produced by the passage of the
hurricane are not part of the same population as all of the other
(benign) winds and therefore the total wind environment cannot be
described by any single statistical function. In this case, what is
necessary is to determine the long-term hurricane climate of the
location and work backwards from that to produce an estimate of the
once in 50-year wind event.

Have you not considered using a technique similar to that used by
Nigel Cook. He uses several methods to project sea level rise. You
could use several databases to predict your 50 year wind event. The
first would be the total record, the second would be the periods
during hurricanes, and the third the total record less those during
hurricane periods. So long as you make it clear which set you are
using.

Unfortunately, this is not an academic exercise. My requirement is to
provided wind and wave data for offshore design purposes. The engineers
require a single number for each. They are not particularly bothered
how it is calculated. They most certainly do not want a range of
numbers. If that is what they are given they have to design to the
highest.


--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
twitter: @TideswellWeathr