### Author Topic: Percentage of Zero Recorded Wind  (Read 376 times)

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#### kaymann

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##### Percentage of Zero Recorded Wind
« on: December 02, 2017, 12:52:31 PM »
A nice breeze can often counter a hot temperature. I have said we usually have a slight breeze going on in this neck of the desert. With 109 days of at least 90°F it was time to check the data!  What percent of the time did we have no wind? My PWS collects data in 5 minute increments or 288 samples a day. So I have no choice but to define Zero wind as maximum wind speed zero in a given 5 minute block. Next I examine all blocks and count only the ones with Zero wind and divide by the total number blocks counted. I was shocked to find we have much more time in the day when we there is no breeze to help cool us down. Now I have to find out if the nighttime doldrums are skewing the results... BTW we have had 16,456 five minute blocks of Zero wind or ~57 days worth YTD
« Last Edit: December 10, 2017, 04:08:19 PM by kaymann »

#### GregJ

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##### Re: Percentage of Wind Zero
« Reply #1 on: December 02, 2017, 01:04:03 PM »
Interesting work.  I may do the same just out of curiosity....  On another note, I wish my clear sky chart had that nice shade of blue like yours....  It's been a long time since I have seen anything but white....

Greg
Davis VP2 with VWS

"Everybody talks about the weather, but nobody does anything about it." -- Mark Twain

#### kaymann

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##### Re: Percentage of Wind Zero
« Reply #2 on: December 02, 2017, 01:16:14 PM »
Greetings,

Blue is my favorite color!

If you want I can send you the formulas and Pivot Table info to segregate the data - but I am betting you will have more fun creating it yourself from scratch!

#### GregJ

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##### Re: Percentage of Wind Zero
« Reply #3 on: December 02, 2017, 01:36:30 PM »
I have been using Power Pivot on my data...  I would be interested in seeing a snippet or two of your code if you are willing to share....  You could PM me....

Greg
Davis VP2 with VWS

"Everybody talks about the weather, but nobody does anything about it." -- Mark Twain

#### GregJ

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##### Re: Percentage of Wind Zero
« Reply #4 on: December 02, 2017, 07:36:32 PM »
Interesting exercise Randall.  I did a 4 year analysis with the same 5 minute increments.  I just threw this together and haven't had time to really analyze it, but the number that jumps off the page for me is that we just had the "least calm" month in the last 4 years.  It has been a nasty month.....  Haven't had time to do the conditional colors yet, but the data is there....

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Thought I'd Share,

Greg

Davis VP2 with VWS

"Everybody talks about the weather, but nobody does anything about it." -- Mark Twain

#### kaymann

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##### Re: Percentage of Wind Zero
« Reply #5 on: December 02, 2017, 10:51:05 PM »
Greg, thank you for the comparative numbers and you kill Marana with a lot less calm!

#### kaymann

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##### Re: Percentage of Wind Zero
« Reply #6 on: December 05, 2017, 07:29:07 AM »
Greg I missed the post about code are you still interested and yes I use a combination of Pivot Tables and very lengthy formulas at times....

#### GregJ

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##### Re: Percentage of Wind Zero
« Reply #7 on: December 08, 2017, 12:03:35 PM »
Thanks Randall....  Actually I was able to put this together fairly easily with PowerPivot.  I still use that since I have Office 2010....  They dropped PowerPivot in Office 2013....  I guess they call that progress at Microsoft....

Greg
Davis VP2 with VWS

"Everybody talks about the weather, but nobody does anything about it." -- Mark Twain

#### hankster

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##### Re: Percentage of Wind Zero
« Reply #8 on: December 08, 2017, 05:27:15 PM »
I would venture to say that there is little to no time when you have no wind. Just that you have time where wind is so low that your anemometer doesn't spin. Depending on the station that can be anywhere where speeds are lower than 1-2 MPH.

If you want to test this, when you are getting reading of zero go outside and start a piece of paper on fire and see if the smoke is going straight up. Here is an example where most anemometers would be showing zero wind speed but obviously there is a breeze for most of this time.

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« Last Edit: December 08, 2017, 05:34:34 PM by hankster »

#### kaymann

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##### Re: Percentage of Wind Zero
« Reply #9 on: December 09, 2017, 02:01:40 PM »
Hankster, I noticed you have a Davis Vantage Vue listed in your WeatherLink. Greg and I are both Davis as well.
Greg's and my anemometer are well placed with the slower speed large cups by Davis Vantage Pro Plus.
I wrestled with the title of this post and toyed with "Percent Absent Cooling Breeze".

If I can't feel it's cooling effect (hazards of Arizona) I am not very interested in measuring it.
Don't get me wrong one of those very expensive three point electronic anemometers would be more awesome than awesome.
However, not worth the expenditure for me personally.

Randall

#### hankster

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##### Re: Percentage of Wind Zero
« Reply #10 on: December 09, 2017, 02:58:00 PM »
However, not worth the expenditure for me personally.

There will soon be one available on the market that is much more affordable. Funny that some worry about making sure their temps are within 1 deg (or less) even though there is no way they can feel the difference. I would hazard to guess winds below 1-2 MPH has as much effect as 1 degree.

There have been a number of studies done (mainly on birds) that shows there are evaporative effects with speeds down to their lowest tested speeds of 2 m/s. Not starting an arguement and I would have agreed with you until I started to look into it more. I have found that if I really focus on it I can feel winds down below 1 MPH. I think if it can be felt there is an effect not only on our bodies but on the environment.

#### kaymann

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##### Re: Percentage of Wind Zero
« Reply #11 on: December 10, 2017, 03:49:25 PM »
Hankster, all excellent and valid points. I do have to say my favorite "breeze" is a 5 mph "cooler".
Also I would take an inexpensive one if it were available simply for the geek factor.

I do have to mention be careful what you wish for:
On Pearl Harbor Day (20171207) we had eight hours of 20 MPH average wind speed and and several gust in upper 40's
Much more cooling than I need...

Randall

#### kaymann

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##### Re: Percentage of Zero Recorded Wind
« Reply #12 on: December 10, 2017, 04:09:26 PM »
Hankster - changed the title to a more accurate data evaluation!

#### Old Tele man

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##### Re: Percentage of Zero Recorded Wind
« Reply #13 on: December 10, 2017, 07:12:52 PM »
WINDY, when Mother Nature attempts to keep-up with Washington Poly-tick'shuns.
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