Building a Mobile Mesonet

[john.sibley]

I'm building my first mobile mesonet for the upcoming hurricane season and I could really use some pointers for the equipment to use. I've seen pictures of people's meso's, but if someone could point me in the right direction of what instruments I need, that would be awesome! Thanks everyone.

 

[Joey Ketcham]

I think before you go spending all the money and time into building one, you need to ask yourself what purpose your mobile mesonet will serve. What do you plan to do with the data collected from it? How will having this better you as a storm chaser?

If you are going to do scientific research, then you will need to spend a couple thousands of dollars on the equipment alone. If you are planning to use consumer brand equipment, forget it. It's not 100% accurate and it'll break.

In my bloody opinion, mobile mesonets serve no other purpose than to draw attention to the storm chasers who uses it. It's a way for them to scream out "HEY, LOOK AT ME.. I STORM CHASE". It's true. This of course doesn't include people associated with Vortex 2 or those involved in legit scientific research. I've been chasing for 13 years and not once have I ever felt that having a mobile mesonet would make me a better chaser.

It's a waste of time and money, just my .02 cents.

 

[Skip Talbot]

Well, instead of preaching my own agenda and disregarding the original poster's intent I can offer some insight. What's definitely not a waste of time and money is knowing the wind speed when you are chasing hurricanes (or supercells for that matter). I use an Inspeed Vortex anemometer. it works quite well and the accuracy is acceptable for personal use (about 2% I believe). The sensors are definitely cheap enough for entry level use. The plastic cups are fragile, however. Although they can withstand winds well over 100 mph, if any debris hits them, you're probably going to damage them. They also have a serial port connector for interfacing with your laptop as well as software to display and log the data and various mounting options. Its a decent start for an entry level weather station.

 

[Joey Ketcham]

Well, instead of preaching my own agenda and disregarding the original poster's intent I can offer some insight. What's definitely not a waste of time and money is knowing the wind speed when you are chasing hurricanes (or supercells for that matter). I use an Inspeed Vortex anemometer. it works quite well and the accuracy is acceptable for personal use (about 2% I believe). The sensors are definitely cheap enough for entry level use. The plastic cups are fragile, however. Although they can withstand winds well over 100 mph, if any debris hits them, you're probably going to damage them. They also have a serial port connector for interfacing with your laptop as well as software to display and log the data and various mounting options. Its decent start for an entry level weather station.

Ok, so even if you buy an Inspeed anemometer, tossing it on your vehicle without any research of the aerodynamics of your vehicle and mounting it so that the air flow around your vehicle doesn't effect the data isn't going to give you much. You can't just toss equipment on your vehicle and call it good. You need to study the aerodynamics of your vehicle, how the winds flow around it and mount your equipment in a position so that it's not effected by the winds flowing against and around the vehicle. If the OP isn't willing to take the time to research this and mount the equipment properly, then what does he expect to do with the inaccurate data collected? How will this help?

Ask any of the engineers who designed and built the mesonets for Vortex, they spent a lot of time and money researching how the aerodynamics of a vehicle effected the data collected by meteorological instruments. They invested a lot of time and money in making sure that the equipment was mounted just right so that the data collected would be accurate. Is the OP willing to invest the time and money for that? If the answer is no, then what is the point of having a mesonet if the data you get is inccurate?

 

[Stuart Robinson]

Can I add my 2 cents worth?

For Hurricane chasing some form of mobile weather recording is an advantage to the chaser. But I agree may be off little real use scientifically. I normally like to record peak wind speed and pressure. Surface Temp and Dewpoint is a secondary consideration.

I use an RM young Anomometer head coupled to a Wind tracker display. I have written my own custom USB enabled data logger to record wind speeds to my laptop. (Note that you need the 0-2.5volt output wind tracker, as the common 0.5V output Wind Tracker peaks output at 100mph)

For Pressure I use a Davis Vantage Pro Console. This I have set the pressure to be accurate at sea level + 20 feet. Depending on your actual height above sea level, the pressure reading will fluctuate if you are mobile and going up and down hills.

Temp and Dew point is recorded from the Davis external ISS sensor which I have cut down to remove the rain bucket etc.

The advantage of my system is that is VERY small as it all has to be packed into a flight case (I live in the UK)

If I was to re do this – I would pick an Ultra sonic Anemometer head – just because they are smaller.

 

[john.sibley]

Thanks for the feedback. I've had the Inspeed Anemometer for two years now and it has held up really well to two trees that have fallen on my vehicle. For $89, it has been worth it. I guess my question is if I'm going to be doing research, should I drop the big bucks on a V2 setup or stay at a consumer level with basic equipment.

 

[Skip Talbot]

If you are doing research, then yes you will have to get scientific grade instruments, which aren't cheap. Simply buying a high end anemometer is not going to result in an accurate measurement, however. Joey is right, you'll need to calibrate it and take into account the turbulence your vehicle creates. I can't recommend a research worthy setup, as the one I've created is for my own personal use and for reporting severe wind events back to the NWS.

 

[John Wetter]

What instruments you get completely depends on the research you're hoping to do. The project manager would want specific payloads with specific response parameters. If this is something personal, just stick with the basic stuff you're doing now.

 

[Aaron Kennedy]

Keep in mind research grade instruments need to be routinely calibrated too... can't just slap them on your vehicle and call it good for the life of the instrument.

 

[Seth Price]

Instrumentation

I am planning on using some National Instruments instrumentation and a LabVIEW program I wrote. I'm still picking out the sensors that I'd want to use. My purposes are strictly for my own fun- answering the question "Can I develop and deploy a set of instruments in this type of (moving)environment?"

I am probably just going to take temperature data this year (and maybe dew point? it's in the works), as it's easy to interface a simple J or K thermocouple, and less easy to develop a decent routine for calculating wind speed and direction in a moving vehicle.

I've thought about getting two anemometers, mounting them at right angles to each other and doing the vector math to figure out wind speed and direction, though they will still go nuts as you drive.

 

[David Wolfson]

Seth, I think that dual anemometers/vanes would be redundant since you need vehicle direction and speed from another independent source, i.e. a GPS. Given that, computing true wind is a rather simple vector calculation.

Google USBTenki, for a sensor I'm experimenting with, FWIW.

 

[Bill Tabor]

Tyler was talking about integrating chaser mobile mesonet with Spotternet or another type of network for online data collection on a large scale. Perhaps you should talk with him about what he requires and how far along that project is.

 

[Chris Heater]

I have a Davis Vue and so far I like it quite a bit. Temperature, wind, dew point, barometer, rainfall (rate and total) is all measured by it, and it was pretty cheap. And no...I'm not out there to say "HEY LOOK AT ME!!! I'M A STORM CHASER!". I want to be ACCURATE when I submit a report and not estimate all the time. I'm sure the NWS like a measured report rather than an estimated, although both are valuable

 

[Jason Foster]

I've used the Davis Monitor II (even trying to sell it) and currently using a Davis Vantage Pro. I know somewhere else I've posted pictures of it, but here is an old blog with photos of my unit. Link to blog.

Like some have mentioned, getting it up above the vehicle as much as possible is important. My doesn't scale high like a V2 mesonet but it's a good 36 inches or more above the roof....enough to make it fairly accurate. So many other things can interfere with the reading that have nothing to do with the station itself (like buildings, trees, etc.).

However, one thing I learned from Chris Collura's "WeatherLab III" is to have at least the anemometer removable from the station. This is exactly how my station is design. I will mention however that if you are chasing lots of cold weather (like I did though these past storms in DC), a polycarb type cutting board will break with all the ice build up, snow, and high wind load from the resistance of the station itself. Stick with PVC, steel or aluminum.

Who have you researched for the various mesonet designs? I'm always looking for ideas myself.

Add: Here is a photo of the station on top of the car in the first DC Mega snow storm:

 

[Ryan McGinnis]

I caught a great presentation last year by one of the guys who worked on the V2 mesonets -- the one thing that really stuck in my mind was that if you want accurate wind measurements, you have to get your instrumentation waaaay up above your car's roof in order to get it out of the car's slipstream. A lot of the setups I see from chasers aren't that terribly high off the roof of the car. That doesn't make them useless, of course, but if your goal is to get accurate measurements, you've got to have it way up there. I think the NOAA probes were 11 foot off the ground and the CSWR stuff was 15 feet.

They all seemed rather fond of Young anemometers for wind; I suspect Young is the gold standard when it comes to accuracy and performance.