Anemometers: Which record sustained (1-min avg) winds?

[Josh Morgerman]

What anemometers do you all use on chases?

I am interested in getting an instrument that can record the sustained (1-minute average) wind-- not only maximum gusts. I have been checking out the Davis line of products, because they come so highly recommended. But they only seem to indicate peak gusts at specific intervals-- not sustained winds. Complete data records are also important to me, and I notice the Davis instruments seem to only record at 1-minute intervals-- not continuously.

Do any instruments below $1,000 do all this? If not, how much do I have to spend and what is recommended?

Also, tips Re: mounting portable anemometers would be greatly appreciated! Thanks!

 

[John Diel]

I doubt that you will find anything in the sub $1K range to get what you want in terms of data logging. There may be something out there, but I don't know what it would be or how reliable.

As far as mounting, do a search in the archives for "Bernoulli Effect" , "Mobilie Mesonet" and you should find a wealth of information regarding this.

 

[Josh Morgerman]

Cool, thanks, John!

Do you recommend any models for logging that kind of detailed data? The $1K is not a hard limit, although like anyone I am pricewise and not wanting to get too nuts.

Re: mounting, I'll do as you suggest and check the archives-- I don't mean to re-hash old discussions.

 

[John Diel]

RM Young and Cambell Scientific seem to to the standards for the grade of data you want. They don't come cheap.

 

[B Ozanne]

I believe the Davis Vantage Pros sample the wind speed every 5 seconds, maybe every 2. Somebody tell me if I am wrong. To get anything better than this you are going to have to shell out a lot of money. Maybe you could pick up an RM Young to do this.

If you set the archive interval to 1 minute you will get the 1 minute average wind speed, also the peak gust during that miunte. Of course this is only going to tick off on the minute, you wont necessarily get the highest 60 second period.

 

[Josh Morgerman]

Hi Bill,

Thanks for the response! I had a long discussion with a very helpful technician at Davis. If you (or anyone else) is interested in the nitty-gritty details, read on...

If I understood the technician correctly:

• The Vantage Pro 2 wind sensor conveys readings every couple of seconds, but data can only be automatically archived once per minute (at the most frequent setting).
• With the archive interval set to 1 minute you will get the momentary wind speed every 60 seconds-- not an average speed for each 60-second period (which would be excellent). So, if I understood him correctly, you wouldn't even get the peak gust for that minute-- just the wind speed at the time of the 1-minute interval reading-- meaning your data could miss some spectacular 30-second gusts if they happen to occur between the archive intervals.

For hurricanes with very gusty and irregular winds, momentary data archiving every 60 seconds just won't do. In the last hurricane I chased (Wilma), the most intense eyewall winds happened in great 15-30-second bursts-- and a once-per-minute data pattern would have missed a lot the action!

As per John Diel's advice, I am talking to the folks at Young and Cambell to see what they have. If they don't have what I need (or they do but it's megabucks), I'll get the Davis Vantage Pro2-- it gets great marks on value and is reasonably priced, and it does remember the maximum gust for each 24-hour period, which is cool.

I am learning a lot in this process!

 

[John Diel]

Seems like the OKlahoma Mesonet, and a fair amount of NOAA stations use the RM Young equipment. At least that what it appears to be. I havne't crawled up on a tower to read the small print, but that seems to be about it. Also, look at the Mobile Mesonet vehicles used in the various Vortex projects. That looks to be RM Young or Cambell equipment. There's a few folks on the board that participated in those events or work much closer with data logging than I do. Hopefully they'll chime in and give some advice.

 

[Gary Shuford]

Data Logger

I just purchased a Nova Lynx desktop data logger for my station. Here is the link:

http://www.novalynx.com/195-ws-16.html

The logger is reasonably priced and has the sample rate you are looking for. Feel free to e-mail if you have any other questions.

Gary Shuford
Gulf Coast Weather Services
Gretna, LA
[email protected]

 

[Josh Morgerman]

Hi Gary,

Thanks very much for the cool suggestion-- that sure does look like a robust data-capturing solution. Some of the language is pretty technical for me, so if you don't mind, I will take you up on your offer and maybe eMail you a couple of questions. Thanks very much!

 

[B Ozanne]

I see what you are saying about the 60 second average, that makes sense. But, that' not the way it works for the gusts. Lets say my Davis samples the wind speed every 5 seconds and transmits it to my console. If a peak gust occurs at the time of the sample it is transmitted to my console and stored as the peak. If the gust is less than 5 seconds long and occurs between the sample periods it will be missed. BTW, replace 5 seconds for whatever the actual sample period is. I've sat around and watched my Davis so I know it does this.

Either way, I'd like to see what you come up. I would love better wind sampling at my hosue.

On another topic. From my experience on Mount Washington, a 30 second gust would be very long. Sure, we would have several minutes of higher sustained winds, but the gusts would still be short bursts above this. Mostly just a few seconds, a long gust would be 15-20 seconds. Occaisionally, they would be very short. Sustained winds would be in the 60's, and out of nowhere a gust to 100mph would come, maybe only last .5 seconds. Even the best electronic anemometers would miss this. The system on Mount Washington is about as close to continuous as you can get. The wind (air) flows down a tube and pushes up a column of water. The height of the column is measured and mechanically transferred to a rotating graph for a nearly continuous record of the wind.
None of which would ever work in your car.

 

[B Ozanne]

Ever think about a sonic anemometer? No moving parts.

 

[Josh Morgerman]

Hi Bill,

Funny you should ask that, because I've been doing a ton of research this week (since I posted this thread), and I've seen a few of these advertised. Are they considered "legimate"? Do they give accurate readings-- or is the standard cup anemometer the way to go? What are your thoughts?

I am a bit overwhelmed with all of the info I collected this week-- almost immobilized by the choices-- so any guidance is appreciated!

 

[B Ozanne]

Yes, sonic anemometers are the real deal. They can be incredibly accurate. If it wasn't for their high cost they would be rapidly replacing 3 cups. Also, a wind vane is not needed with a sonic. On Mount Washington we use a sonic during the summer months, but it can't take the winter icing. There are heated sonics, but they didn't work on Mount Washington...and you can't use a crowbar on them either.

I can't vouch for any specific brands though. I'm starting to see some consumer grade sonics for sale, but I don't know how they compare to the high end Vaisala models.

 

[Josh Morgerman]

UPDATE

OK, so I did a bunch of research and had a bunch of discussions with folks at Davis, R.M. Young, Campbell Scientific, and Novalynx.

Thanks, John, for recommending Young and Campbell. You were completely right-- to get what I really want would cost some good money. The customized solutions quoted by these two companies were several thousand dollars and pretty much out of my price range. (Maybe I will treat myself to this quality of solution if I sell a lot of DVDs this year. :wink: )

I am still talking to Novalynx, which seems to be less expensive-- and Gary (who posted on this thread) is happy with his Novalynx solution.

If that solution does not turn out to be viable, I will probably do the Davis Vantage Pro2 and just accept that I won't be able to log more complex data, like 1-minute averages and so on.

My only real complaint with the Davis solution is that-- if I understood the sales rep correctly-- the datalogger will not automatically record the highest gust for an archive period-- it will only log what is happening at the exact archive time. But this won't do-- for reasons Bill cites above. Also, my experience with Hurricane Wilma in October-- which had wildly fluctuating winds in the back side of the eyewall (i.e., up and down between maybe 30 kt and 80+ kt in very short periods)-- tells me I would miss a lot of great data with this solution. I would much rather know the highest gust for an entire archive period-- not what might be happening at one specific moment in time.

Wanting to log the max gust every 1 minute or every 5 minutes doesn't seem like such an extravagant wish to me. Is it?

Any advice, anybody?