Hi,

You need to be a bit more precise. Wind speed is continuously recorded. Then speed is averaged using one hour time scale (also 3 second and one minute are used). The maximum value is reported as the hourly wind of the day.  This hourly wind is good for something which doesn't move much. 

For sensitive structures another wind speed is used which is known as the gust. Gust is about 3 second average wind speed (some countries use one minute average). There are correlation between gust and the hourly mean. Codes simplify this by adapting a gust factor (about 2), which you multiply the hourly wind speed.

I don't know Fryberger's and Dean  formulae. But is gust you need to use and it doesn't come from one measurement per day. If you have a series of them, do you use the maximum or the average?  I suggest  you investigate how they define it want it, i.e.  hourly mean, 3 second mean one minute mean or something else, for example  requires 99% percentile. They are numerically different.

To complicate the issue, American use another measure which is the "fastest mile"

Information your seeking may be publicly available. 

Read more here.

https://en.wikipedia.org/wiki/Wind_speed

I would say the answer depends on 2 factors:

1) If there is a diurnal cycle in the wind, then a single measurement at 12:00 every day will miss the variability over the full day and bias your results.  I would expect most locations to have some diurnal cycle in wind-speed, especially if they are close to a coast and especially in summer-time.

2) Assuming there is little or no diurnal cycle in the wind, you would need data from more days to compensate for the paucity of data within each day to obtain reliable estimates.

Which would provide "better" data for your purposes: 2920 measurements, taken once a day for 8 years; or 2920 measurements, taken every 3 hours (8 times /day) for 1 year?   You have the same amount of data either way.  The first data set would provide some information on interannual variability but miss any diurnal cycle, while the second data set captures the diurnal cycle and so would give better estimates within a year, but miss out on interannual variability. 

Ideally, you would really like to have the 2920 measurements per year for 8 years or more, to get the best of both worlds....

As mentioned by Sirius Yasseri, it is unusual to have just 1 wind measurement per day.  Most weather-stations do much better than that.  Still, we have to work with the data we've got; in your case it's probably a good idea to just keep in mind the caveat that the data you have is missing whatever diurnal cycle might really be present.

Dear professor Yasseri, Dear professor O'Brien, thank you so much for answering, It was well explained and extremely beneficial.

Greetings.

Nouar.

As I have seen from Meteosat pictures from sand storms over North Africa and Near East, sand storms can develop and pass over quite large areas in several hours, so, having only one wind measurement per day, you risk not mention such events or have inaccurate data on their duration.

One measurement per day for wind is not a good idea, i.e. not if there is a significant diurnal cycle and if it is a coastal location as mentioned above.If possible, you should try to get other data from your coastal area to understand how the diurnal cycle looks like. It might be possible to "construct" wind speeds for your location using a diurnal cycle from nearby.

There was just a comparable discussion here how changes in the number of observations per day will affect your data. See the link below. I think it is crucial to take correct wind data. Otherwise your results are just flawed.

https://www.researchgate.net/post/What_happened_to_wind_speed_in_coastal_New_South_Wales_Australia_during_2000-2015_mostly_La_Nina_or_neutral_conditions

Dust storms can be caused by the collapse of thunderstorms which typically occur in the afternoon. So, IMHO, one measurement at 12.00 is likely to miss many major dust storms.

Hi Nouar,

I must congratulate you. Your question has attracted a lot of discussion.

Dear professor Yasseri, a good question could contribute on well understanding, and consequently on producing accurate and reliable knowledge, herein manifestes the impact of beneficial assistance of high level experts as you are professor. My gratutude and respect.

Nouar.