Weather stations, which sensors to use and when

When organisations deploy weather monitoring systems, they often focus on the wind speed due to the potential damage from strong winds, especially when it is not monitored. However, greater insight about the weather is possible by monitoring other variables in addition to the wind.
Weather conditions such as extreme temperature, rainfall and snow can also be disruptive, but they do not happen within seconds like a gust of wind. Thus, organisations have more time to react when a weather forecast warns about these events.

Measuring Wind Direction with a Weather Vane

An anemometer by itself can only measure wind speed, but not its direction. Even if wind speed is measured with high accuracy, the user cannot get a complete picture if the wind direction is unknown. The potential effects of wind change depending on the direction from which it blows, and this is very important in applications like structural design and wind power projects.

Due to the importance of wind direction, many anemometers come with a built-in weather vane. However, if you only have a basic anemometer set up, adding a weather vane is strongly recommended for static systems.

Wind speed and wind velocity are not equivalent concepts. Wind speed is simply the value that describes how fast the wind is moving, while velocity is a vector quantity that has both speed and direction. An anemometer by itself only measures wind speed, but velocity can only be measured with the combination of an anemometer an a wind vane. This concept is very common when calculating wind turbulence intensity, wind vortexes and funnelling.

Adding a Second Anemometer to Your Weather Station

Wind conditions vary by location, but they also change with altitude. As a result, wind measurement at a single height does not provide a complete picture of site conditions.
The variation of wind velocity across a short distance is called wind shear, and the wind profile for a given site can be extrapolated from measurements at different altitudes.
When a weather station is equipped with two anemometers at different heights, its data can be used to analyse wind shear.

Wind shear must be considered when designing a high-rise building, since the wind load varies significantly from ground level to the upper floors.

Tracking Atmospheric Pressure with a Barometer

Atmospheric pressure has a significant impact on the weather. When the pressure reading on the barometer is lowering, precipitation is likely; on the other hand, rising pressure indicates that weather conditions will improve.
With low pressure, air rises and carries humidity from ground level. Air cools down as it increases, and its capacity to hold moisture is gradually reduced. Air humidity condenses into clouds, and precipitation follows.

Air tends to descend towards ground level with high pressure, minimising the formation of clouds. This is why high pressure systems bring clear skies.
The combination of low pressure and high temperature normally brings the most severe storms. Since warm air holds more humidity, more water is reaching a high altitude and condensing into clouds. As a result, increased precipitation can be expected.

The Importance of Relative Humidity

Relative humidity is another weather variable that influences the thermal sensation for humans, and it can be monitored with a relative humidity probe for your weather station. As explained above, air humidity also influences precipitation - if a low pressure system meets humid air, rainfall is likely during the following days.

For us humans, air humidity changes the perception of both hot and cold temperatures, I'm sure you have experienced this during holidays:

• If the air is warm and humid, sweat cannot evaporate from human skin quickly because the air is already saturated with moisture. The weather feels hotter because humid air limits the speed at which the human body can release heat.
• When the weather is cold and humid, humidity tends to condense on clothing, reducing its insulation capacity. Since body heat is lost faster, the weather feels colder.
• Consider that low humidity is not comfortable either, since it can irritate the skin, eyes and respiratory system. Particles can also stay airborne for longer when humidity is low, which favours the spread of dust and viruses.
• In addition, low humidity causes the accumulation of static electricity, which can damage sensitive electronic equipment. This is often a worry when working in countries like Spain or Italy.

How do I add all these sensors to my WINDCRANE and why?

Businesses with outdoor operations are normally concerned with wind speed; being unpredictable and capable of changing in an instant, the wind is one of the main weather risks. However, monitoring other weather variables provides greater insight about the conditions that can be expected. For example, if a barometer registers a downward trend in atmospheric pressure, unfavourable weather is likely in the following days.

WINDCRANE Max can be your favourite weather station as it is able to connect up to 14 sensors. In case you didn't know, WINDCRANE origins come from the Wind Energy sector where the systems were used and deployed by Logic Energy to be full advanced remote weather monitoring systems left in the middle of nowhere for over 2 years. The data collected during all this time then was used to calculate the efficiency of a potential wind farm. In these cases accuracy needed to super, as not only wind speed increases by a factor of 3 for energy and loads but also it adds to the compounding effect of the life of the wind farms over years.

This is why WINDCRANE has an accuracy of 0.00002%