Farm weather forecasts: how do they work?

Sep 22, 2023 • 3 min read

At the heart of every farm, the weather plays a key role. It determines the course of every farmers day, influencing every aspect of their work, from field preparation to harvesting. Every cloud, gust of wind and drop of rain plays a crucial role in the success of their crops. But how do they come up with the weather forecasts that guide their actions?

Observation and data collection

When it comes to forecasting the weather, it is essential to have accurate measurements of current weather conditions. To do this, various measuring instruments collect data on a continuous basis.

Weather stations: These facilities continuously measure information on temperature, atmospheric pressure, humidity and wind, providing an overview of local and regional weather conditions.

Satellites: These orbit the Earth, capturing images and data on clouds, temperatures, winds and other features.
Radar: monitors precipitation and clouds in real time by sending out radio waves that bounce off water particles in the atmosphere, providing information on the intensity and movement of precipitation. On the Sencrop application, you can track the movement of rainfall using a visual representation of this data from rain radars.

Sounding balloons: These are equipped with weather sensors and released into the atmosphere to provide information on atmospheric conditions at different altitudes.
On-board sensors: These days, sensors are also fitted on board aircraft or ships to collect data in real time.

It is important to increase the density of observations, in particular by installing more weather stations. Indeed, to provide good weather forecasts, we need to be able to access current weather data from anywhere in the world. For example, to forecast what the weather will be like in Brittany next week, I need to know what the current weather is like in New York, Melbourne or Moscow, everything is interconnected

Modelling forecasts

Weather forecasts depend on what are known as "weather models". These models transform data collected from various sources into detailed predictions of future weather conditions. These are supercomputers that simulate and anticipate the complex movements of the atmosphere by combining physics, mathematics and computer science. Everything is simulated and predicted: temperatures, wind strength, cloud density, rainfall intensity, etc. Behind a weather model comprises of thousands of calculations, figures and equations to produce the most reliable weather forecast possible.

Today, there are many weather models. It was in the 1980s that the first weather models saw the light of day, in conjunction with the emergence of computer technology. The best-known weather model today is undoubtedly GFS, an American model. In France, Arome and Arpege have been developed by Météo France and are used to produce accurate, detailed short-term forecasts.

Each model has its advantages and limitations. Their reliability can vary from one region to another, from one country to another or even from one measurement to another. Although numerical models have made enormous progress, they are not infallible. The longer the forecast horizon, the greater the uncertainties due to the complexity of the atmosphere and sensitivity to initial conditions.

Integrating Weather Forecasts into the Daily Lives of Farmers

Weather forecasts are at the heart of farmers' daily lives, influencing their decision-making, helping them to optimise their resources, manage risks more effectively and cope with climate change.

Decision-making: Weather forecasts enable farmers to plan their various farming operations wisely: when to plant, treat or irrigate, for example.
Optimising resources: When it comes to spraying pesticides, for example, weather forecasts can be used to determine the optimum time to spray, in the right doses. This avoids product drift and the possible need for additional applications.
Risk management: Farmers are exposed to many weather-related risks, such as thunderstorms and frost. Weather forecasts are there to help them manage these risks. By anticipating the risk of frost, you can trigger your frost control system at the right time to protect your crops as effectively as possible, while limiting the cost.