NYC Wind Speed – Fitting Distributions

Risk Modeling – NYC Wind

I just posted my first Mathematica model today.  It demonstrates modeling NYC Wind Speeds.  Look for it under the new Model entry under the main menu.  It is stored as both a notebook (.nb) and as a computable document (.cdf).  To use the CDF, you will need to install the Wolfram Mathematica CDF Player.

I am currently using Mathematica 11.2 and the notebook and CDF are  saved in Dropbox.


Windy Day
It is a little windy today isn’t it?


The workbook reads in the maximum wind speeds from NYC using the WeatherData Mathematica function. Those values are converted from km/hour to mph. From that converted data, Mathematica then fits several different statistical distributions and displays that fit.  I chose these distributions because of their various properties, such as positive support including infinite support such as normal or log-normal.  I also included the simplest distribution used within ERM, which is the triangular distribution.  I also fit the extreme value distribution for modeling extreme winds.  However, I find that these distributions don’t seem to get wind speeds in excess of 100mph, which is the certified wind speed protection that is required by NYC skyscrapers.

I also use the Mathematica function FindDistribution to find the best ten distribution to fit the data as well.  Here we look at the maximum, mean and the 98% quantiles of these ten distributions and examine the Economic Capital metric.   Even though Economic capital doesn’t make sense with a wind speed model, it is a means to determine what wind speed above the average wind speed would occur in a 1 in 50 year event.  This is measured by the 98% percentile of a distribution less the mean of a distribution.  Since,  98% = 100% – 1/50, the 98% percentile would tell you what the speed would be in a 1 in 50 year event.  The excess of this over the mean, would be the excess wind speed above the mean, that you would need to address, if you wanted to cover a 1 in 50 events.

Wind Risk Links

Below are several useful wind risk links:

Windstorms and Tornadoes Hazard Analysis for New York City


NYC – Coastal Storms Risk Assessment

Sandy spared New York’s skyscrapers, but high-rises carry high risk during hurricanes

List of NY Hurricanes

The 1893 NY Hurricane and the Disappearance of Hog Island

Skyscrapers May Shiver and Sway, but They’re Perfectly Safe (Just Stay Away From the Windows)

ATC Wind Speed by Location

Severe Wind Gust Risk for Australian Capital Cities – A National Risk Assessment approach

A simulation model for assessing bird wind turbine collision risk

Model-Based Estimation of Collision Risks of Predatory Birds with Wind Turbines

Managing Wind Pool Risk with Portfolio Optimization

Wind Gust Forecasting: Managing Risk to Construction Projects



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