Weather Station - Advice for a new one

If you are thinking of building a new weather station you might want to take some time to consider a few questions. A well designed station will be accurate, reliable and easy to use. You will not achieve this until you have a design (and installation) which can survive the problems it will encounter.

As you will soon learn, your intentions and your plans are not what does the work. They are good steps along the way, but it's the actual hardware and software installation that must perform.

Your original intention may be to start small. Along the way you may want to re-consider various assumptions and decisions. Changes in infrastructure, your knowledge, or advances in technology (or your budget) may make "the stuff of dreams" readily possible.

Bringing something new into existence requires a pioneer spirit. You will be doing something which, so far, no one else has either bothered with or has known how to do. This is an opportunity to catch people's imagination about what is possible. It can be an exciting adventure. It can also be a real pain. Like the pioneers, sometimes you run into unwelcome challenges.

From the perspective of one weather station's experience, here are a few issues you may want to consider:

Who is the customer?

You probably started with yourself, and may imagine a few interested people located nearby. Depending on your "user interface", you could have a much larger audience.

Your potential customers include anyone who can access your information. For a display on the wall, it's anyone who might wander by. For a web page, it's potentially anyone, anywhere, who has internet access.

Example: The weather station on Hoodoo Butte was originally envisioned as an aid to ski area operations. Made available on the web, it has since been used by campers, climbers, fishermen, forest fire investigators, weather forecasters, geophysicists investigating magma movement, and parasailers for flying conditions. And maybe a few others who haven't dropped us a note.

You are not a slave to this extended audience, but realizing that they exist is a start. It may help shape your plans for what you do.

What do they want (or need) to know?

Different types of customers will have different interests and needs. Understanding these needs, if even in a superficial way, may help you better understand what features a well-rounded weather station might include. This part of the process is meant to uncover new ideas.

Sometimes the customer doesn't realize what they need: Where one may spend hours out on a cross-country trail, would it be handy to be reminded when sunset happens?

Sometimes the customer has a different perspective: US-based sites may forget that a lot of the world measures temperature, air pressure and wind speed in metric units.

Knowing these needs, you can start assembling a list of the features for your site. Some parameters you may measure and report. Others information may be best handled with a reference to somewhere else. Web pages are built around the idea that linking to someone else's information is almost as good as having it yourself.

For a weather station, links to the local National Weather Service office are an easy way to access forecast information. Local web cameras add immeasureably to understanding what the weather is doing.

At some point you will realize that some features are impractical. For lack of time, money, access, or technology, some of these features will have to be moved to a "wish list".

Before you close-out your imagination, consider whether a "weather station" might be too limited. Consider if a "measurement station" may be what you really wanted. Weather variables might be a start, but what else might be of interest?

What do you need to measure?

Having determined the information of interest, what needs to be measured? What we are interested-in is normally directly measureable, but not always:

Rime icing is affected by temperature, humidity and wind speed. Where it forms depends on the wind direction. If you are interested in the "rime icing hazard", there are four basic parameters which need to be measured. Additional analysis will be necessary in order to state the magnitude of the hazard.

Some measurements may require interpretation before yielding what you want. If you measure overall snow depth, but want to report "new snowfall" amounts, you will need to keep some history of your snow depth readings. Reporting river flow rates, given a water depth gauge, would need an equation or look-up table.

Commonly-measured Parameters:

Those "non-weather" measurements could be a real challenge, but for now we're just trying to identify what might be interesting to measure.

Where will you measure it?

For every sensor, the measurement site (top of mountain, base area, ...) needs to be selected, followed by the specifics of how the sensor will be mounted.

Before you place a sensor, consider the location:

With a general location in mind, how will the sensor be mounted?

How will you measure it?

The conditions experienced at a site will affect what sort of instruments will function or survive. The top of a mountain is subject to high winds and rime ice; it is no place for a light-duty plastic wind vane. Creek beds may be scoured by flood waters and debris; not a good place for a free-standing measuring stick.

Consider sensing technologies which will survive the likely abuses.

How will you move the information?

How will you get the sensor information to some central location so that it may be stored or summarized for use?

How will you display the information?

Just because you measure or generate information does not require you to report it. A back-up air temperature measurement might be useful if the primary instrument goes bad, but until then redundant information just clutters the report. A "local" weather page used inside a ski area might include an analysis for rime icing or avalanche hazard. That's handy for the lift operators and public safety folks, but is probably not of interest to the general public.

You may want to create different products (i.e. web pages) for different customers.

What powers it?

At every location you have a powered device, consider:

Who is going to design the station?

Assuming you don't order a complete "station in a box", who is responsible for determining how it all fits together?
- If the wind sensor puts out a twelve volt pulse, but the datalogger can only handle a 5 volt signal, how do you make them compatible?
- What software is going to talk to the RS-232 serial port on the snow depth sensor?
- Since RS-232 is only good for maybe a hundred feet, how will you communicate with the snow depth sensor (or datalogger) if they are located thousands of feet away?
- What happens if lightning strikes a part of the system?

The design stage is when the strengths (and weaknesses) of a station are determined. Perhaps unwittingly.

The potential to gracefully accept some upgrades might be nice. Leaving enough room in a box, extra conductors in a cable or power supply capacity might make the difference between a simple addition or a significant extra project in the future.

Design is normally followed by ordering the hardware. Get this backwards, and you may be saddled with hardware which has no hope of surviving the environment. Go ahead and use what you're given, but have the understanding that it may have to be replaced if it cannot handle the severe service it may be exposed to.

Who is going to install the station?

The technical knowledge needed to install a station is comparable to the design effort. Issues not anticipated in the design may arise in the field, requiring on-site re-design (or re-writing of software).

The skills and knowledge used in installation would be useful when it comes (later) to maintenance.

Who is going to keep it running?

By the time you've got the station running you will have realized just how much work it takes to install and debug the basic setup. Keeping it running will be a continuing challenge,

Sometimes it may seem like there is a conspiracy between people, nature and software to bring the station down. These "challenges" should be more rightly viewed as issues which you failed to either anticipate or guard against. To restore the station the problems need to not only be fixed, but they should ideally be re-designed out of existance. Station design should be viewed as a process of continual improvement.

Assuming your station survives, you may decide to upgrade its capabilities. At that time some of the answers to the above questions will have changed, and so the station design will need to change.

While you don't need a full-time employee, you will need someone willing (and able) to tackle the occasional problem. Some problems might be easily handled coaching someone over the phone. Other problems may require an on-site visit from the technical folks.

To the extent you make access to the site possible, you will get assistance. Make it a pain, and you will probably feel it too. Example: Allowing the maintainer to have keys to the involved buildings, so they can be accessed in the off-hours. The times when you are available, and when your consultant is available, may not overlap.

Web Page Features

On a web page, consider including features like:

Parting Thoughts

A weather station can be an expensive and time-consuming hobby. It's not impossible to build, despite the impression you may have gained from reading these notes. It can be a useful and practical form of "continuing education" for the designer, builder & maintainer.

From the "customer" perspective you might be surprised by the number of people who find your station useful, and in the variety of ways it gets used. There can be great satisfaction in watching it operate in the face of truely nasty weather (as opposed to climbing up the tower to fix something ;-).

Remember that measuring instruments should be calibrated. Reporting false or misleading data doesn't help your reputation. While telling the truth may be annoying at times, it should more than pay-off when the news is good.