Weather Measurements: A Comprehensive Guide

Weather Measurements: A Comprehensive Guide

Staying up to date with the latest weather forecast is a daily routine for many of us. But have you ever stopped to think about the terms used to describe different weather conditions? From high pressure to humidity, there's a whole vocabulary dedicated to understanding the atmosphere. In this blog, we will dive into the world of weather measurements and definitions, providing you with a comprehensive guide to help you make sense of it all. Get ready to become a weather expert in no time. So, grab a cup of coffee - it's time to dive into weather 101! 

Rainfall- the quantity of rain falling within a given area in a given time. Rainfall is measured in inches but is also commonly represented in millimeters (mm). A rain gauge is a modern instrument used to measure rainfall

Relative Humidity- the amount of water vapor present in the air expressed as a percentage of the amount needed for saturation at the same temperature. A Hygrometer instrument is used to measure humidity.  

Barometric Pressure- this is also known as atmospheric pressure. Both are defined as the pressure within the atmosphere of the earth. A barometer measures atmospheric pressure in units of measurement called atmospheres (atm) or bars.  

Station Pressure - also known as barometer reading or sea level pressure, is the pressure measured at a weather station, usually expressed in units of hectopascals (hPa) or inches of mercury (inHg). Station pressure is important in weather forecasting because it provides information about the air pressure at a particular location, which can be used to make predictions about the local weather. Station pressure is adjusted to sea level using a standard atmospheric pressure to account for differences in altitude, allowing for easier comparison between different locations and a better understanding of the weather patterns affecting a region.

Barometric Pressure vs Station Pressure

Barometric pressure and station pressure are often used interchangeably, though they have distinct meanings. Barometric pressure is the atmospheric pressure that measures the weight of air in a certain area. It helps indicate if weather patterns will change soon and can be seen on most everyday weather forecasts.

Station pressure on the other hand, is a measurement of air pressure taken at a specific location. It is typically read from a local weather station or any instrument specifically used for measuring atmospheric conditions like the KestrelMet 6000 weather station or Kestrel meters. Unlike barometric pressure, station pressure measurements are not standardized since they are taken directly from an individual location and may vary depending on altitude. As such, they provide a more precise level of information related to regional or localized conditions rather than global ones.

In summary, both barometric and station pressures measure air weight but at different scales: while barometric provides data on a large region or country, station pressures offer more detailed readings focused on particular locations - making them useful for those taking into account smaller-scale climate dynamics in their operations.

For more on this topic, visit our blog Barometric Pressure vs. Station Pressure: What's the Difference?

Wind Speed- the rate at which air is moving in a particular area. Wind speed is measured in miles per hour (mph) and is captured by an instrument called an anemometer.   

Wind Direction- is the true direction from which the wind is blowing at a given location. For example, a northerly wind blows from the north to the south. Wind direction is measured in degrees clockwise from the north. A wind vane is a common instrument to measure wind direction.  

Wind Chill- a still-air temperature that would have the same cooling effect on exposed human skin as a given combination of temperature and wind speed. In simple terms, the colder the air temperature, and the higher the windspeeds, the colder it will feel on your skin if you are outside. The wind chill index takes into account heat loss from the human body and is used to determine dangerous conditions that could lead to hypothermia or frostbite.  

Leaf Wetness- describes the amount of dew and precipitation left on surfaces. It is mostly used for monitoring leaf moisture for agricultural purposes such as fungus and disease control, detection of fog and dew conditions, and early detection of rainfall. 

Soil Moisture- soil moisture is the water content of the soil. It can be expressed in terms of volume or weight. Soil moisture can represent the water that resides in the pores of the soil and can be determined by a number of factors beyond weather conditions.  

Soil Temperature- is simply the measurement of warmth in the soil. The ideal soil temperatures for planting most vegetation are 65 to 75 degrees Fahrenheit. Soil temperature is also dependent on soil moisture and pore space.  

Solar Irradiance- the output of light energy from the sun, measured in the form of electromagnetic radiation. Solar irradiance is measured in watts per square meter (W/m2) in SI units.

   

Dew Point- is the temperature at which a given parcel of humid air must be cooled, at constant barometric pressure, for water vapor to condense into water. The condensed water is called dew. The dew point is a saturation temperature.  

Heat Index- heat index is what the temperature feels like to the human body when relative humidity is combined with the air temperature. 

UV Index- tells you how much ultraviolet radiation is at ground level on a given day, and its potential to harm your skin. UV radiation is a component of sunlight that can cause tanning and sun burn in the short term and cataracts and skin cancer in the long term.  

Wet Bulb Globe Temperature (WBGT)- measure of the heat stress in direct sunlight. This considers temperature, humidity, wind speed, sun angle, and cloud cover. This differs from heat index because it takes into consideration temperature and humidity.  

Cloud cover - Cloud cover refers to the fraction of the sky that is covered by clouds. It is expressed as a percentage, with 0% meaning a completely clear sky and 100% meaning a completely overcast sky. Cloud cover measurements are important for weather forecasting, as clouds can have a significant impact on temperature, precipitation, and other weather conditions.

Air quality - Air quality measurement is the process of assessing the levels of pollutants in the air, such as particulate matter, ozone, nitrogen dioxide, and sulfur dioxide. These measurements are used to determine the overall healthiness of the air and to determine if it meets certain air quality standards. Air quality measurements are important for public health and environmental protection, as air pollution can cause serious health problems, including respiratory and cardiovascular diseases.

If you want to nerd out on reading about lesser-known weather terms used in scientific research and meteorology, click to go to the last section.

Tracking Weather Measurements from Your Own Backyard

When you are looking to track a wide range of measurements, a KestrelMet 6000 weather station is your best instrument.

All of our handheld meters and KestrelMet weather stations ensure that you are fully prepared for the day or an upcoming outdoor event. These stations give you the ability to view the temperature, humidity, barometric pressure, wind speed, wind direction, rainfall, and much more. Everyone can greatly benefit from knowing the latest on what’s happening with their local weather.

KestrelMet 6000 Weather Station

The KestrelMet 6000 Cellular Weather Station is a reliable, cost effective, all-in-one professional weather station for commercial, industrial, educational, and research applications. Kestrel Instruments is making hyper-local weather monitoring affordable and easily deployable with its first weather station.

The KestrelMet 6000 offers a full suite of commercial sensors for accurately monitoring the following:

  • Wind speed
  • Wind direction
  • Barometric pressure
  • Relative humidity
  • Temperature
  • Rainfall
  • Optional Solar Irradiance, Leaf Wetness, Soil Moisture & Soil Temperature

View all your KestrelMet weather station data on your Ambient Weather Network (AWN) personal online dashboard or on the AWN app available on Google Play or the App store.

Kestrel 2500 Weather Meter

This Kestrel 2500 Handheld Weather Meter is a highly accurate, easy to use device designed for monitoring environmental conditions. It provides users with comprehensive measurements of both indoor and outdoor temperatures, humidity, barometric pressure, wind speed, and even the density altitude - making it an ideal choice for applications that require reliable data on a variety of conditions. 

Measurements

  • Altitude
  • Barometric pressure
  • Temperature
  • Wind chill
  • Wind speed/ air speed

Kestrel 5500 Weather Meter

The Kestrel 5500 Handheld Weather Station is the worlds most complete weather meter AND the world most portable weather station. This Kestrel meter does it all. The Kestrel 5500 measures every environmental condition plus wind direction, cross wind, and headwind/ tailwind. This platform offers a large, high-resolution display with ease of font readability. Like all Kestrel Meters, the Kestrel 5500 is drop-proof, dust-proof, waterproof and able to withstand harsh environments without damage.

Measurements

  • Altitude
  • Barometric pressure
  • Compass pressure
  • Crosswind
  • Density altitude
  • Dew point temperature
  • Headwind/ tailwind
  • Heat stress index
  • Relative humidity
  • Station pressure (absolute pressure)
  • Temperature
  • Wet bulb temperature
  • Wind chill
  • Wind speed/ Air speed

Kestrel DROP Data Loggers

Accurately monitor temperature, humidity, pressure and more indoors and outdoors and easily access current and stored data on your mobile device. Kestrel DROP Data Loggers are built to survive harsh environments while being simple and easy to use. The Kestrel LiNK App allows users to view their DROP data in real time, view charts, and easily send data via email or share on social media.

The Kestrel DROP D1 allows you to wirelessly monitor and log your temperature conditions with this tiny handheld unit. If you’re looking for something simple, this data logger is for you. With just measuring temperature, this is a great unit to start off with!

The Kestrel DROP D2 lets you know your temperature and humidity conditions everywhere. This specific data logger allows you to measure the following:

  • Dew point temperature
  • Heat stress index
  • Relative humidity
  • Temperature

Lastly, Kestrel DROP D3 allows you to get more advanced environmental monitoring. This Data Logger is designed to monitor and record a full suite of environmental conditions such as:

  • Barometric pressure
  • Density altitude
  • Dew point pressure
  • Heat stress index
  • Pressure trend
  • Relative humidity
  • Temperature

The weather is something that impacts our lives daily. It is important to know the basic terminology of weather measurements so you can get the most out of your Kestrel Sensors and Weather Stations.

Lesser-Known Weather Measurements for Meteorology and Forecasting

Weather enthusiasts often want to dig deeper into weather terms that add depth to our understanding of the atmosphere. For example, "dew point" is the temperature at which water droplets begin to form, and is often a better indicator of how humid the air feels compared to relative humidity. Another interesting term is "equilibrium level," which refers to the height at which the rate of moisture being added to the air by condensation is equal to the rate at which it's being lost through evaporation. And don't forget about "convective available potential energy" (CAPE), a measure of the amount of energy available for thunderstorm development. By exploring these and other lesser-known weather measurements and terms, we can gain a more nuanced appreciation for the complex and dynamic nature of our planet's atmosphere.

Convective Available Potential Energy (CAPE): CAPE is a measure of the amount of energy available for thunderstorm development in the atmosphere. It is calculated based on the temperature and moisture profile in the atmosphere and is used to predict severe weather events such as thunderstorms and tornadoes.

Equilibrium level - also known as the level of free convection, is a term used in meteorology to describe the height in the atmosphere where the rate of moisture being added to the air by condensation is equal to the rate at which it's being lost through evaporation. It is the height at which a parcel of air, lifted from the surface, will remain at a constant temperature and stop rising. The presence of a strong inversion layer at the equilibrium level can prevent further vertical development of clouds and thunderstorms. Understanding the equilibrium level is important for forecasting severe weather and for making decisions about air traffic, agriculture, and other activities that are sensitive to atmospheric conditions.

K Index - a measure of atmospheric instability used to predict thunderstorm activity. It takes into account temperature, dew point, and pressure readings to determine the likelihood of thunderstorms developing in a given area.

Vertical Wind Shear - a measure of the change in wind speed and direction with height in the atmosphere. It is important in predicting severe weather events such as thunderstorms and hurricanes, as strong wind shear can disrupt the formation and development of these systems.

Mixing Height - Mixing height refers to the height in the atmosphere where pollutants, such as ozone and particulate matter, become well mixed with the air. This measurement is important for air quality forecasting, as higher mixing heights can lead to increased air pollution levels.

Geopotential Height - Geopotential height is a measure of the height of a pressure surface above sea level. It is used to analyze and forecast large-scale weather patterns, such as fronts and ridges, and to identify areas of high and low pressure in the atmosphere.

These are just a few examples of lesser-known weather measurements that play important roles in weather forecasting and analysis.